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How can we prevent this deterioration?

There are several ways that shelf life can be extended, but these remedies inevitably change the texture, making it more soft.

• Add butter or vegetable oil, up to a level of about seven percent of the total batch weight. Then, even if the patties lose moisture, the texture remains fairly palatable. In addition, the fat has a “doctoring” effect on the sugar crystallization, which delays the formation of white grained patches.
• Add highly humectant ingredients, such as a sorbitol solution, invert sugar or high fructose corn syrup. They should be added up to a level of about five percent of the total batch weight.
• Substantially increasing the corn syrup will lengthen the shelf life, but will make the pralines chewy rather than short-textured. This may be partially offset by the use of 60 DE corn syrup, or partial replacement with high fructose corn syrup.
• Some producers have tried coating pralines with confectioners’ glaze, as is used for panning.

Glaze is not easy to apply. It must be sprayed on, and if the bottoms are not coated, then drying out will still occur. Glazing is moderately effective, but it gives the pralines a rather artificial appearance.

Pralines are seldom produced on a large scale, because the timing of the patty-forming stage is rather critical.

Only in the South do we have that much patience! END

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For this method of production, the water content of the premix is far lower than in the traditional kettle cooking formula. There is no opportunity to add certain ingredients late in the cooking stage, so all are included in the premix. Gelatin may be degraded because of the high cooking temperature.

The cooking time is brief through this type of system, and so there is potentially less starch gelatinization. This may be compensated by addition of modified starches to the formula.
Cooker-Extruder Cooking

In this case, it can be possible to cook to the final target moisture content. About 3% of moisture is flashed off or removed by a vacuum section in the cooker. Here again, far less water is included in the premix, and gelatin may be excluded in favor of modified starch. Because of the extreme shear action, gelatinization is better than in a scraped-surface cooker, even though the cooking time is brief.

A Unique Texture

Licorice is unlike any other candy because of its cooked dough texture. From licorice “allsorts” to cherry twists, a wide range of varieties is possible.

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Figure: Invertase hydrolyzes sucrose into glucose and fructose

The more common use for invertase is to soften or liquefy fondant cream centers, or cordials, which are chocolate coated. Invertase acts specifically on sucrose in solution. It has no effect on other sugars or on crystalline sucrose.

Fondant Cream Centers (Cordials)

In a freshly-made fondant cream center, or a cordial, the texture is firm and handleable. By adding invertase, at a level of two to six ounces per 100 pounds, a gradual softening or liquefaction occurs. The effect of the invertase is not instantaneous, so there is time to form and chocolate coat the centers before significant softening occurs. Complete softening, or liquefaction, requires about three weeks at the normal storage temperature of 65 degrees F. Lower storage temperatures will slow or delay the process.

Fondant cream centers are a two-phase system. The liquid or continuous phase is composed of water, corn syrup and sucrose in solution. The dry phase is composed of small crystals of sucrose. Invertase converts the dissolved sucrose to dextrose and fructose. These monosaccharide sugars together have a higher solubility than sucrose alone. So, some of the sucrose crystals can then dissolve, and the invertase “inverts” this sucrose. The process stops when the liquid phase is fully saturated with a combination of corn syrup and invert sugar. Dependent on the formula, softening or complete liquefaction may be achieved. END

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The particular vegetable oil used will determine the tempering conditions for coating. END

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Recalibration in boiling water (212 degrees F at sea level) may not be sufficiently accurate. The thermometer may read correctly at this temperature, but may be incorrect at 245-250 degrees F. So, it is preferable to calibrate at the normal use temperature range.

This may require an oil bath and the production thermometers should be calibrated by comparison with a certified laboratory thermometer. Many thermometers become inaccurate because steam or water enters the mechanism. Waterproof thermometers are preferable, or remote reading models where the dial or digital read-out is well away from steam or water splashing.

The bulbs of thermometers should not rest on the bottom of a kettle when reading the desired temperature. The heated surface will be higher in temperature than the cooking batch, and by conduction the thermometer will read a higher temperature than is the case.

The location of the thermometer bulb is important. It should be in a well-agitated area of a batch or product flow. This will help prevent the bulb from becoming coated, and thus insulated. A coated bulb will read lower than the actual product temperature.

Thermometer dials should be large enough for easy reading in single degrees. Many supervisors use small pocket dial thermometers that are marked in increments of five degrees F for process control checks. These are not sufficiently accurate for most purposes.

There are still candymakers who decry the use of thermometers and claim that judgment is more reliable. The thermometer is not the only control instrument in use, nor is it perfect for every application. But this one instrument has probably contributed more to consistent control of processing than any other which we use.     END

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These candies require the addition of measured quantities of acid or acid salts.

In the case of pectin jellies the pH range for proper setting is critical, and in the all-sugar products the weak acid salt causes a controlled level of inversion during cooking.

Water dissolves salts during its progress through soil and rock to rivers or reservoirs. The level of dissolved salts (or “hardness” of water) varies considerably from area to area, and may vary from season to season. The dissolved salts are generally alkaline so they will tend to partially neutralize acids used in formulations.

Therefore, in processes where control of pH is critical, the hardness of the water should be frequently monitored. For any such formulations, a graph can be constructed to determine how much acid to use dependent upon water hardness.

The taste of water varies considerably from district to district, and in some cases, has a distinctly unpleasant smell. Where this is so, it may be quite difficult to make candies with “clean” flavors.

Another case in point, was a project to help a small manufacturer improve the flavor of fruit-flavored chocolate centers. I made several samples using known, popular flavors, but nothing tasted as it should. I then tasted the homemade fondant, and it also had a distinctly unpleasant flavor.

Finally, the water itself was tasted and found to be the real culprit.

In such cases, it may be necessary to use bottled water in the formulations or install a water purification system.  END

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Some yeasts and molds can grow in the Aw range 0.60 to 0.70, but by the addition of acid and/or salt, and/or anti-microbial preservatives, there is little danger. Above Aw 0.75, we must be concerned.

We can increase the proportion of bound water by increasing the humectant level. This will lower the Aw, but it will also soften the texture. This may be compensated for by the addition of gums that have strong, water-binding properties. But there will be textural effects because gums increase viscosity or produce gel-like structures.

Salt and acids are frequently added to candies. They will have some influence on lowering the Aw, but they tend to create conditions hostile to microbial growth.

If we cannot formulate products at a totally safe Aw, it is product to add a preservative such as sodium benzoate or potassium sorbate. Aw is normally measured at 20 degrees C. It should also be noted that at higher temperatures, the Aw will increase.

Calculation of e.r.h. is quite complex, although computer software is available for this purpose. Measurement of the Aw using a meter and sensor can be done quickly on a sample of product. END

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A limiting factor on the degree of aeration is viscosity. As the batch becomes aerated, it becomes more viscous, largely due to the cooling effect on the incorporated air. It may then become too viscous to flow from the outlet port.

The kettle mixing gear must be sufficiently robust for very viscous masses.

In some cases, aeration may be achieved with the use of a stiff frappe. Some moisture will inevitable be added with the frappe, and this approach may not be suitable for all pulled products. Crystallization may be initiated by addition of fondant or powdered sugar.

Some viscous masses may be aerated in vertical batch beaters like those used for marshmallow. Alternatively, a batch pressure beater or a continuous pressure beater may be used.

Success depends largely upon the fluidity of the mass at the aeration stage and its resistance to crystallization under conditions of high shear-rate mixing.

I have successfully pulled caramels by the use of a continuous pressure beater. Additives such as flavors and fondant can then be incorporated by the use of injection pumps and static pipe mixers.

Continuous tubular or trough mixers may be used instead of pulling, but it is usually hard to achieve enough residence time to obtain sufficient aeration.

Sigma-blade batch mixers have an action and speed similar to pulling machines. The main problem is the difficulty of discharging, unless the mixtruder type is employed.

Mixing and extrusion equipment designed for chewing gum can incorporate air into chewy masses but may cause crystallization.

We should really be thankful for the vertical pulling machine. The prior alternative was by hand, which was back-breaking work.

END

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In hard candy, if the proportion of inversion is too high, the candy will be excessively hygroscopic and may even distort or flow in storage.

If there is too little inversion, spontaneous crystallization may occur.

I have known batches to become a solid mass of crystals while still in the vacuum kettle or to crystallize as soon as they were poured onto a cooling table.

In fondant or cream centers, too much inversion will cause slack syrup batches, whereas too little will lead to coarse, dry, grainy batches.

When making grained mints, unless the proportion of inversion falls within a very narrow range, then the desired “meltaway” texture cannot be produced.

There is no doubt that products made by causing inversion during cooking have excellent texture when correctly processed.

If, as an alternative, a measured quantity of invert sugar is added to a formula, some discoloration (caramelization) may occur in cooking, so the finished product may not be as white as when the inversion method is employed.

However, except in very well controlled, continuous processing, if inversion is caused by the use of acid ingredients, it is difficult to ensure consistent product.

For most types of product, the use of corn syrup as a “doctor” material, or to “cut the grain,” is a more reliable method of control. END

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The usual sequence is to place all of the sugar and starch into the mixer and than add the adhesives, color and flavor while mixing until a homogeneous mass is produced.

The next step is to form the shaped lozenges. The equipment that is normally used forms a continuous sheet of about 1/2-inch thickness by means of a horizontal multiple-screw extruder.

The sheet is then rolled down to the required thickness by passing through multiple pairs of horizontal rollers.

The sheet is heavily dusted with dry starch to prevent sticking to the rollers.

Next the sheet passes beneath a set of vertical cutters that stamp out the required shape as well as imprint a product name or company logo on the surface.

The shaped lozenges are delivered onto starch-dusted trays and the web is reworked through the extruder.

In the preceding formula the moisture content is approximately 7.5 percent.

The lozenges must be dried to between one and two percent moisture to make them hard.

The lozenges are spread in trays that have perforated bases to assist the removal of moisture. There should be a sufficient gap between the trays to permit free circulation of drying air.

The trays are held in rooms where the temperature and relative humidity are controlled to maximize the rate of drying.

Depending on formulation and thickness, drying may take days. Drying rooms should have fans to circulate air between the trays.

If drying is too rapid, a hard skin may form that will delay drying of the inside.

If the temperature is too high, the lozenges may expand and lose their flat appearance. At a high temperature, there may be much loss of volatile flavoring.

Typical drying room conditions will have a temperature of about 100-110 degrees F and a differential of about 25 percent between the equilibrium relative humidity of the product and relative humidity of the air.

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Sweating back is due to compaction and arrangement of the crystals, which squeezes syrup to the surface.

This syrup must then be dried off with more sugar before the next application of syrup.

If regular refined granulated sugar is used, the coating will be coarse and gritty. It is customary to use an extra fine grade of crystalline sugar. Typical particle distribution is:

• Retained on U.S. sieve #30 – not more than two percent;
• Retained on U.S. sieve #40 – not more than 2.5 percent;
• Through U.S. sieve #70 – at least 40 percent; and
• Through U.S. sieve #140 – not more than eight percent.
This grade of sugar will provide a pleasant texture and a semiplastic coating.

If powdered sugar is used, then the coating is likely to be hard.

By using powdered sugar, the syrup must be spread over a larger surface area.

Syrup films between particles will be thinner than with crystalline sugar. Consequently, the coating will have little plasticity.

Not every particle of powdered sugar will be coated with syrup, but the effect will be a much harder coating.

Powdered sugar is only used for the final coating to fill in hollows between crystals of sugar and provide a smooth surface.

Hardness is caused by excessive drying between coating and final smoothing.

Normal conditions would be 70 to 75 degrees F, and 45 to 50 percent RH for overnight drying.

Hardening may also occur in storage if the conditions are too warm or of very low humidity and if the packaging does not provide good moisture barrier.

Some manufacturers use high maltose corn syrup to extend shelf life.         END

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temperature may drop well below the boiling point, causing the pectin to come out of solution. If this occurs, the pectin may burn on the inner surface of the kettle, leading to inefficient heat transfer, slow boiling, and a weak gel.
10. Add the color, and boil to 226 degrees F.
11. Shut off the steam. Add the flavor.
12. Only when the batch is ready to be placed into the depositor should the last half of the citric acid solution be added, and thoroughly mixed in. If all of the acid is added too soon, dropping the pH to between 3.2 and 3.5, the batch may begin to set prematurely either in the kettle or in the depositor, especially if the temperature drops below 190 degrees F. If the gel has begun to set before depositing into the starch moulds, the agitation from the pumping action through the nozzles will disturb the set, thereby causing a weak structure in the finished piece.
13. Deposit into starch, and set for at least three hours.
14. De-mould, steam, and sugar-sand.

END

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In some cases, the gelatin is hydrated in its own weight of water, then stirred into a boiled syrup of 80-85 percent solids. In other cases, the gelatin is hydrated in twice its weight of water or more, then warmed to a solution.

This solution is mixed into a syrup of about 90 percent solids.

If the stirring is gentle, the latter method produces fewer bubbles. The amount of water added to the gelatin is governed by the desired solids and viscosity for depositing.

Whichever method is employed, there are techniques that can be used to remove the bubbles.

If the mix of hydrated gelatin and boiled syrup is prepared in a bottom-outlet steam kettle, then clarification is easier.

In the clarification stage, occasional shots of steam are let into the kettle jacket to cause convection currents that accelerate the movement of bubbles to the surface.

The clarified syrup that is then drawn off from the bottom of the kettle is virtually bubble-free, and the scum remains in the kettle. A vacuum kettle can be used to remove the bubbles after mixing, and this method is very effective.

However, one effect of the vacuum stage is to cool the syrup and increase its viscosity.

Removal of bubbles by vacuum must usually be accompanied by additional heating to maintain a suitable viscosity for depositing.

A modern development for processing gummi jellies is the pressure coil cooker, otherwise known as a static cooker. In this equipment, solution and concentration of the mix is achieved by a combination of heating and pressure within the cooking coil.

The residence time within the coil is very brief, and the utilization of pressure allows the mixture to be dissolved in less water than when using open atmospheric cooking kettles.

It is possible to incorporate the gelatin with the water used for solution of the sugar, and due to the brief cooking time, the gelatin suffers little degradation.

Using this system, incorporating color and flavor with in-line mixing devices, the jelly syrup is immediately ready for depositing in a bubble-free, hot, fluid state.

Having made bubble-free jelly by batch or continuous methods, it is still possible to aerate the syrup unless care is taken.

Pumping and delivery to the mogul hopper must be arranged in such a way that pumps do not incorporate air, or that air bubbles are not formed as the syrup flows into the hopper.

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("Microwave" continued from previous column)

 

 

Although it takes longer, it is preferable to use the defrost mode for chocolate. With care, this mode can also be used for warming after cooling in the tempering procedure.

Small sample batches of hard candy become cool and too hard very quickly, especially if they are to be striped or filled. If this happens, it is simple to warm the candy back to a plastic state. The normal heating mode should be used, but the batch should be frequently turned.

For some small batches, complete cooking may be possible. For simple syrups, such as fondant, a temperature in the range of 235 – 245 degrees F can be reached after several minutes of full-power heating.

If bob batches of cream centers are to be made, the fondant portion can also be liquefied in a microwave oven.

Boiling to much higher temperatures is possible.

But it is especially important that the plastic container will not deform or collapse at these higher temperatures. It is not really practical to cook caramel by microwave heating because the milk protein coagulates and separates. It is really necessary to stir while boiling milk formulations.

Many companies need a fast method of moisture determination. The following is accurate to within 0.5 percent.
• Weigh a clean, small petri dish and lid. Record the weight.
• Weigh into the dish approximately two grams of pulverized sample. Record the weight.
• Place the sample into the oven.
• Heat for one minute at full power, then turn off for one-and-a-half minutes. Repeat this procedure 10 times, to give a total heating time of 10 minutes. The intervals of one-and-a-half minutes provide cooling time to prevent burning.
• Remove the sample, place the lid on the dish and allow to cool. Reweigh the petri dish and dried sample, then express the weight loss as percent moisture content.

This method may require some variation. The objective is to subject the sample to maximum heating periods without scorching.

A timer can be used to control the on/off periods. Although the method is not as accurate as some others, it does provide a fast result.

Future development will potentially bring microwave heating into greater use for candy processing.

In the meantime, it provides a convenient means of heating small batches.

END

 

 

 

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(continued from previous column)

 

These coating fluids are usually applied in a revolving pan or tumbler, but the abrasion of tumbling while drying tends to rub the corners bare. If a coating of powder is applied to prevent this, then the eating character of the product may be changed. By minimizing abrasion of nut pieces generally, the bloom problem will be diminished. Excessive abrasion ruptures more oil cells, and the nuts may have an oily surface before chocolate coating.

Obviously, the thicker the coating of chocolate, the longer it will take for nut oils to seep through. Many companies double-coat products that contain nuts. But another factor is the hardness of the chocolate. Well-tempered and properly cooled chocolate has a harder texture than that which is poorly tempered. So, good tempering and correct cooling are of primary importance.

Milk chocolate will inevitably be softer than dark chocolate because of the presence of milk fat. But fortunately, bloom does not show quite as readily on milk as on dark chocolate. However, good tempering is still important, and it may be desirable to reduce the milk fat.

Another approach is to formulate the chocolate coating for the maximum possible hardness. We know that Brazilian cocoa butter gives a softer set than cocoa butter from most other areas. It is also a fact that Malaysian cocoa butter gives a harder texture than most others. The hardness of chocolate will be improved if Malaysian butter is used.

Lecithin also tends to make for a softer texture. If the lecithin is removed from the formula, then it will be necessary to increase the cocoa butter content to maintain the standard viscosity. And if the cocoa butter content can be further raised, consistent with an acceptable viscosity, then the set texture will be further hardened, provided that a hard variety of cocoa butter is used.

Purchasers of chocolate coatings cannot significantly influence the hardness once the chocolate has been received. But, by discussion with the supplier, it may be possible to formulate a harder coating.

Since the deterioration process is one of a fluid oil seeping through the coating, this will be delayed if the oil can be made more viscous by cold storage. Storing in freezing conditions will virtually prevent seepage as it also hardens the chocolate. But, of course, it is not practical to keep such products frozen throughout their whole shelf life.

The rule should be to keep sensitive products cool at all times. Frequent changes of temperature, even cool temperatures, will accelerate oil seepage by causing expansion and contraction. END


For more information, please contact Pat Magee at plmagee@earthlink.net

 

  

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(continued from previous column)

 

. . . and caramel can be made by taking regular formulations for these products and diluting to the required viscosity. It is not advisable to dilute with water as this may raise the water activity of the filling to the point that mold growth occurs during storage.

It is preferable to dilute with a syrup that has a water activity too low for mold growth, such as high DE corn syrup, high fructose corn syrup, or warmed dissolved invert sugar. These syrups will raise the sweetness level, but it may be possible to compensate by adjustment of the base formula before dilution.

Jellies are not easy to formulate because they normally have to be deposited hot. However, gelling agents such as agar, low methoxyl pectin and vegetable gums may be used to make a viscous syrup that forms a weak gel.

Meltaways and peanut butter fillings are fairly easy as the liquid phase is fat, as in chocolate. By manipulation of the fat melting point and proportion, good formulations can be constructed.

Truffles can be made by preparation in the normal manner, then dilution with syrup and/or a liquid vegetable oil.

The critical part is to achieve a viscosity that matches the chocolate to be used at 86 to 92 degrees F. In many cases, this will be a judgment call, but I advise the use of a viscosimeter, and prefer the Brookfield model HAT.

This model has been generally adopted by the U.S. candy and chocolate industry for measurement of chocolate viscosity.

The procedure is to measure the viscosity of the chocolate that is to be used for one-shot depositing, when tempered, and match the viscosity of the filling to it at the tempered temperature.

Obviously, this complicates the process of preparing fillings.

But it cannot be assumed that the same quantity of diluting syrup will always produce the same viscosity.

Variables in the preparation and age of the base batches before dilution can affect the viscosity. So, it is better to measure and, if necessary, adjust the filling viscosity just before it is to be used. END

 

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(continued from previous column)

 %  %  %
Granulated sugar 36 32 36
42 DE corn syrup 5   4   --
65 DE corn syrup --   --   2
Invert sugar   --   --   3
Water   9    8    9
Frappe   --   5    --
Plus color and flavor

The conventional procedure is as follows:
• Mix and heat the sugar, syrup(s) and water until the sugar is dissolved.
• Boil the syrup to 240 degrees F. Lower boiling will give a softer, more creamy texture. Higher boiling will give a more rigid texture but graining will occur earlier.
• Blend the fondant and boiled syrup together, and mix in color and flavor.
• The mix temperature should be about 160 degrees F. If too cool, a thick, soft wafer will result. If too hot, graining will be rapid. Continue mixing until the temperature falls.
• Deposit into discs on paper or rubber plaques.

This type of fondant candy can easily be “shocked” into premature graining.

Fierce heating can cause this, as can cold drafts or depositing onto a cold surface. Room conditions and the temperature of plaques should be about 80 degrees F. Cooling should be in an atmosphere of 70-80 degrees F, and the wafers will normally set in 20-30 minutes.

They can be packed as soon as they are set. Packaging should be designed to resist loss of moisture, and storage must not be in warm, dry conditions.    END

The extremely high viscosity of hard candy is one of the factors that prevents graining. But if the candy, by its hygroscopic nature, can absorb some moisture into its outer surface the viscosity is greatly reduced and the candy will consequently grain.

In this grained or partially grained state, the sugar crystals will trigger additional graining in any fresh hard candy to which it is added.

So, if scrap is to be used by kneading it back into a fresh hot batch, it must be either fresh and warm, or fresh and dry.

If it is impractical to always ensure that the scrap is in either of these two states, then it should be utilized as a rework syrup. Scrap can be reduced to a syrup, neutralized, decolored, largely deflavored, and adjusted to a standard concentration. In this form, it can be reworked as a portion of the boiled syrup for fresh batches of hard candy, or for a variety of other candy products.

Grained scrap is not the only possible cause of graining in hard candy sticks. Especially if it occurs most frequently in strong colors, it may be connected with the quantity of liquid color that is being used.

To produce strong colors, a fairly high level of color is required. It is always preferable to use paste or jellied dyes, or powdered dyes specifically designed for inclusion in hot candy. Excessive liquid can lower the viscosity, permitting graining to take place.

Having ensured that rework scrap and colors are being incorporated properly, another safeguard is to raise the level of corn syrup in the formulation.

Higher levels of corn syrup increase the viscosity. Ratios of 60:40 or 55:45 sugar to corn syrup are common and usually resistant to graining. The textural effect of raising the corn syrup level will be to make the candy more tough and less crunchy. It will also reduce the ingredient cost.

If these measures fail to cure the problem, then a detailed investigation of the process should be undertaken. There can be several other contributory causes to the problem of graining in hard candies. END

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Because of this practice, the consistency of the paste from the mixer varied greatly. Since this mixer served five refiners on an on-demand basis, the consistency of paste being fed to the refiners was quite variable.

In addition, mixing times were variable. To get production underway at the start of a shift, the mixing time might be only seven minutes, whereas 20 minutes were written into the standard procedure. Since the efficiency of mixing influences the extent to which dry particles of sugar and milk are wetted with cocoa butter, this was an important factor.

With paste of varying textures fed to the refiners, it was impossible to set the rollers to grind a full-width band of paste to the desired fineness.

The remedies were obvious, and after implementation, the fineness of the chocolate paste improved. END

Some people can never hand temper or dip successfully because they have naturally “hot” hands, which de-temper the chocolate or cause streaks in the dipped candies.

As the pool of chocolate decreases, it should frequently be replenished by small quantities of warm chocolate which must be thoroughly mixed in before dipping is resumed. By this practice, a pool of chocolate can be kept in temper for a few hours. The secret is to frequently add small quantities of warm chocolate and thoroughly stir them into the tempered mass. Streakiness may be due to insufficient mixing.

Dipped candies, placed on trays or plaques, are then held in a cool area to set. The temperature for cooling should be 55-65 degrees F, and setting will take 30-40 minutes. It is not a good practice to put dipped candies into a refrigerator or freezer. This type of cooling could cause a dull finish and condensation. END

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Prevent almond bark products from streaking

By Reg Groves


Question: We have not been able to determine the cause of an occasional streaky appearance on our almond bark products. The chocolate is tempered properly, and the cooling tunnel is working properly. Our enrobed products produced on this same line have a consistent gloss. If this is fat bloom, why does it show up only periodically?

Answer: Follow-up to this query determined that the tempered chocolate is spread into a thin layer on the belt by operators, some of whom were wearing thin plastic gloves.

Gloves are sanitary, but do not provide insulation from the heat generated by the enclosed hand. And since plastic gloves do not allow perspiration to evaporate, the temperature of the hand is raised.

Some people also have naturally warmer hands than others. This body heat can cause “fat bloom” by remelting the desirable seed crystals on the surface of the chocolate being spread onto the belt. This allows undesirable crystal formation, with a resultant streaky appearance.

In fact, the streaking may not show immediately, but may be visible in several days, after the bloom has time to develop. The use of insulated gloves can provide protection against significant heat penetration into the chocolate, but for hand operations such as this, workers who have naturally cool hands should be selected. END

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Several factors influence the bubble size formation and stability of the foam. These include formulation, moisture content, type and quantity of aerating agent, temperature/viscosity of beating, speed of beating and type of beating equipment.

Physical stability means resistance to syrup drainage, which forms a syrupy layer at the bottom of each marshmallow.

If the foam has many large bubbles, then the syrup matrix is distributed over a smaller surface area than is the case with small bubbles. Larger bubbles tend to coalesce or collapse, creating syrupy voids. Free syrup then drains down through the marshmallow and causes a layer of syrup at the bottom of each piece. Often, this can be cured simply by creating a foam of smaller, more even-sized bubbles.

How can we achieve this? All of the above factors play a part, but we must have a means of seeing and measuring how small and even the bubble structure is.

This is where the microscope plays its part. If we make a microscope slide of a sample of the marshmallow, the bubbles can easily be seen. To be more sophisticated, we can use a reticle to measure the bubbles and make photo micrographs to set standards.

By variation of the above factors, we can determine what process conditions create the smallest bubble structure and set operating standards.

This discussion has dealt with open batch processing, but the same procedures can be applied to batch or continuous pressure beaters.

It is easier to achieve consistent specific gravity and bubble structure with pressure beaters. END

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In this hot state, the paste is rather soft and sticky, but after partial or complete cooling, its texture is plastic, non-sticky and excellent for extrusion.

Fruits and novelty shapes are often made by hand, using hinged book moulds, then hand decorated by air brushing or with fine paint brushes. There is a machine that will form novelty shapes onto a conveyor, but these, of course, have one flat surface.


Peanut oil released during grinding acts as a binder, but the grinding is so coarse that small pieces of peanut remain. A typical recipe might be:
LBS. OZS.
Powdered sugar  55  0
Coarse ground, roasted peanuts  45  0
Peanut flavor        2
Lecithin        3

The ingredients are mixed together to wet the dry particles as much as possible with released peanut oil. The lecithin acts as a wetting agent and antioxidant.

Since peanut marzipan does not bind together very well, it is not normally extruded or sheeted and cut. Instead, special machines have been developed that compress the mix into large circular tablets and then bunch-wrap them.

Hazelnut or filbert paste is also more opular in Europe than in the U.S. There is a wide variety of textures. At one end of the scale, hazelnut paste, which is quite liquid when warm, is simply stiffened and sweetened with powdered sugar. At the other end, fondant cream centers may be flavored with hazelnut paste. Then there are textures that are deposited into chocolate shells, sheeted, then wire-cut, layerd in candy bars, or used as fillings in hard candies. So there is no typical formula for hazelnut paste.

Where fluidity for depositing is required, a hydrogenated fat may be added to a hazelnut/sugar mix. This will provide fluidity when warm, but a set when cooled. Where a viscous, pumpable or extrudable texture is needed, hazelnut paste will be stiffened with dry powdered ingredients.

Another form of paste, often called Krokant, is made by roasting hazelnuts with sugar, and then, after cooling, fine-grinding to a paste.

Peanut butter is very popular in the U.S., but not so elsewhere. A starting formula for extrusion would be:
LBS. OZS.
Peanut butter       40  0
Powdered sugar    55  0
Hydrogenated veetable oil 90 degrees melt   5  0
Lecithin 4
Kraflow spray-dried whey     1  8
Peanut flavor 4

Such a formula would be prepared in a dough mixer. Peanut butter candies are not easy to extrude, since the oil liberated in grinding makes for a rather slack texture. It can also bleed through the coating as fat bloom. END
Both factors contribute to a firm structure.

Most likely, the fudge was placed into the freezer too soon, where the final crystallization would take place more slowly, resulting in a finer crystal structure, or possibly failure to fully crystallize.

When thawed to room temperature, the “set” would be soft.

Inconsistent final cooking temperatures should not be overlooked as a potential cause of a soft set.

Thermometers should be calibrated weekly.

To make an assumption that thermometers are reading accurately is frequently a cause of varying texture. END
(continued from previous column)



It became obvious that the texture was more coarse towards the end of a production shift, than at the beginning. The real cause of coarse texture was that the production rate of batches per shift had been increased. This resulted in batches having less time for cooling in the mixing kettle and in the depositor hopper. The depositing temperature at the end of a shift was about 190 degrees F to 200 degrees F. As the shift proceeded, the train of equipment became higher and higher in temperature. The effect of this higher temperature is that more of the sugar crystals in the fondant become dissolved, and there is less fine crystallization at the point of depositing. In these circumstances, large crystals develop in the fudge, as it cools in trays, producing a coarse texture.

The remedy was to apply cooling to the jacket of the mixing kettle, and to the jacket of the depositor hopper. The cooling water in each case was set to temperatures which would cool the batches in the mixing kettle to about 200 degrees F, and in the depositor hopper to about 160 degrees F. Thereafter, consistently fine-textured fudge was produced throughout the whole shift. END



It would be advisable to add potassium sorbate or sodium benzoate as mold-inhibiting agents. The legal maximum for these preservatives is 0.1 percent of the weight of the finished product.

Turning white at the edges of the pans may also be due to having insufficient syrup.

The white appearance is uncontrolled crystallization, and Karo syrup is the principal ingredient that helps to retard the rate of crystallization.

Other causes may be insufficient stirring to cause enough crystallization before pouring, or pouring into pans that are too cold. Fudge should not be “shocked” in its cooling stage, or “white spot” crystallization may occur. Fudge is quite a complex confection.

It is a solution (emulsion and dispersion of ingredients) that is then partially crystallized. Hopefully, a consistent product results.

But many fudge formulations originated in “grandma’s kitchen” where shelf life was never a consideration. This one for goat’s milk fudge probably had a similar origin. Without some understanding of the technology involved to convert a domestic formulation to a commercial product with good shelf life, the problem can often be baffling. END

Cooling before pre-bottoming can also help. In some cases a cold plate may be installed before the bottomer to chill the bottom surfaces and speed chocolate setting. This can be especially beneficial with soft centers to make the bottom surface firm as the chocolate is less likely to peel off a rigid surface than it is from a flexible one.

Double bottoming
Placing two bottomers in the line can be beneficial to achieve a thick bottom coating. But unless there is sufficient time and correct cooling conditions between the two bottomers, and between the second bottomer and the enrober, the coating may not be improved. The second bottomer may simply wash off part of the first coat, and the same may occur in the enrober. It is often better to extend the cold plate rather than to install a second bottomer.

Compound coatings
Many compounds, especially if based on lauric fats, set much faster than chocolate. In such cases, two to three minutes of cooling time on the cold plate conveyor can suffice. Special care must be taken with lauric fat compounds to avoid condensation on the cold plate conveyor. The moisture absorbed into the bottom coating can result in a strong soapy flavor due to hydrolytic rancidity.

Extrusion of centers
Some leakers may be caused by compression in an extruder with insufficient time for re-expansion before chocolate coating. The chocolate coating contracts as it sets exerting a slight pressure on the center. If this is combined with un-relaxed compression by the extruder then leakers or splits can occur.

Leakers occur frequently through thin bottom coatings. Ideally, eight minutes should elapse between extrusion and coating, especially if the center is aerated and, thereby, more compressible. END

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Drained maraschino cherries, or cherries preserved in alcohol, are placed into the moulds by hand or by mechanical dropper. Size grading of the cherries is vital to ensure fillings of consistent volume.

Cream fillings are so formulated that they are fluid enough to deposit at about 85 degrees – 90 degrees F. But upon cooling they are viscous enough to support the final application of chocolate, which completes the encasement.

Then, over a period of a few weeks (not in freezer storage), the cream filling becomes liquid due to invertase action. In this case, too, a high sugar fondant results in a more fluid cordial.

When shell moulding a truly liquid cordial, it may not be viscous enough to support the final application of chocolate through the stages of depositing and cleaning off the excess. This can result in leakers.

A remedy is to spray a thin coat of cocoa butter onto the surface of the cordial and then cool the raft of cocoa butter before the final chocolate application.

Some shell moulding systems can compensate for variable cherry size by sucking out excess syrup from over-filled moulds. And in some cases, the bottom of chocolate is applied as a moulded disc rather than a liquid deposit. This ensures better sealing against leakage and more consistent bottom thickness.

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The incorporation of fats reduces the stickiness. In most hard candies, it is impractical to add fats, but in brittles and caramels, the higher the level of fat, the better. The addition of glyceryl monostearate is extremely beneficial and provides better lubrication for cutting, chewing and resisting adhesion to wrappers.

Packing materials

The major requirement for packaging films, bags and cases, is that they should have good moisture barrier properties. Not all films or laminates provide this, and before selection, consultation with suppliers is advisable. Ideally, there will be three layers of protection – the wrapper, the bag (or carton), and the shipping case.

There are several choices of films or laminates for twist wrapping, fold wrapping or fin-seal wrapping. Sealing is better than twisting or folding. Similarly, there are several choices for bag material.

Cartons are usually moisture proofed by shrink-wrapping in film. The shipping case can provide a moisture barrier either by lining with a film bag or by coating with wax or varnish. In some instances, shipping cases may be shrink-wrapped.
cooked product pipeline. Mixing is then achieved by some form of in-line mixer.

Pressure beating – Conventional batch pressure beaters may be used in some circumstances for soft caramels. But the aerated mass easily becomes too cool and viscous to be expelled by air pressure.

Again, in some cases, conventional continuous pressure beaters may be employed. These incorporate bubbles of air at a controlled pressure and flow rate into a continuous stream of product under pressure.

The mix then passes through a disk, or cylindrical configuration beating chamber that is also under pressure. The beating cylinder houses a spinning rotor with multiple pins that intermesh with fixed pins. By forcing the mix through the beater, the air bubbles are finely divided and distributed through the caramel mass.

Continuous pressure beaters are usually designed for more fluid material, a higher level of aeration, and lower temperature operation that is the case for caramel. But they can be made to aerate satisfactorily, albeit at a low production rate.

State-of-the-art – In fairly recent years continuous production lines have been designed for aeration of hard candy, eliminating the pulling stage that is common in such products as Starlite Mints. These machines continuously vacuum cook a syrup that is extracted from the cooker and pumped under pressure into an aerating tube.

The aerating tube operates on exactly the same principle as conventional continuous pressure beaters. But the tube is designed for high temperature operations and for a high rate of production. The aerated mass flows through a back pressure valve and is usually spread on a water-cooled steel conveyor, that cools it to a plastic state for forming. 

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Another key to consistent depositing is control of the caramel temperature. In some cases, batches of cooked caramel are dumped directly into the depositor hopper. At the beginning of the batch, with the temperature at about 230 to 240 degrees Fahrenheit, the caramel is fluid, and flows down into the crevices below the nut pieces. Toward the end, the caramel may be cooled to about 150 degrees Fahrenheit, and be so viscous that it forms large tails.

Consistent depositing temperature can be achieved by partially cooling cooked caramel, and then holding the caramel in a temperature-controlled hopper. The latter factor is important. Many hoppers are controlled manually, by guess work setting of water and steam valves. The optimum depositing temperature depends upon the formulation and equipment. Usually, it falls somewhere in the range of 160 to 200 degrees Fahrenheit, but consistent control of temperature is a desirable objective.

Cooling of the caramel after depositing can also present some problems, especially to shelf life. In continuous systems, caramel is deposited onto a layer of nut pieces on a conveyer belt, which then passes through a cooling tunnel. In many cases, cooling is excessive, and caramel is cooled below the dew point of the workroom atmosphere. By its nature, caramel is hygroscopic. If cooled below the dew point, it will immediately attract a film of moisture from the air while traveling through the open area between the tunnel and the enrober.

This film of moisture can initiate graining, which eventually spreads through the whole caramel portion. The caramel should only be cooled to the ideal coating temperature (between 75 and 80 degrees Fahrenheit), and never be left in the tunnel during production breaks.

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Moisture content
Dependent upon the type of nougat, the moisture content may range from five to 11 percent. Water in the formula is normally derived from a boiled syrup (the bulk of the batch) and from water in a frappe.

The residual moisture strongly influences the softness or hardness of nougat. The moisture in the frappe portion is usually controlled by a combination of measurement as well as controlled concentration of a syrup. Aerating agents require certain proportions of water for aeration, and the bulk of the aerated portion (frappe) is usually a syrup. The mix of these two is aerated to a controlled specific gravity.

Control of the final product moisture content can usually be achieved by variation of the boiling temperature of the bulk boiled syrup. As a rule of thumb, 2 degrees Fahrenheit is roughly equal to one percent of moisture in the syrup. So, by adjusting the boiling temperature up, or down, we can reduce or increase the final moisture content, thereby influencing the texture. Here again, incremental adjustments are recommended, followed by texture evaluation.

 

Aeration

Nougats are aerated confections and may range in specific gravity from about 1.1 to 0.6. The ratio of air incorporated strongly influences the texture by weakening the structure. A higher ratio of air (lower S.G.) gives a texture that is easier to bite through. Aeration is another controllable aspect of nougat manufacture.

Fat

Fat is normally added as a lubricant to mastication and machining. The proportion of fat added will affect the stickiness and chewiness of the candy. It must be borne in mind that fat is a defoaming agent and will reduce aeration especially if mixing time is excessive. 

For more information please contact the author.   END

 

 

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