BUT I Need Just a Little More Tempered Chocolate…

Extending the Capacity of a Tempering System by Back Filling with Unseeded Chocolate

By Dennis Teets

In the last article we looked at controlling seed growth over time and thus extending usage time by controlling a tempered chocolate’s flow properties. In this article we will expand on the control of seed growth to include expanding the capacity of a tempering system through backfilling with unseeded chocolate.

Backfilling reduces the thickness of a chocolate by not only decreasing the size and number of crystals, but also by increasing the space between crystals. This is accomplished by combining the melting of some of the crystals and agglomerates with diluting the mass with unseeded chocolate to increase the space between crystals. This combination of melting and dilution decreases the interaction of the crystals with each other, and thus provide a thinner chocolate. The differences between seeded and unseeded chocolate are seen in Figure 1. The top (a) is unseeded chocolate at about 93°F (34°C). Note the rounded corners on the folds verses the sharp corners on the folds of the chocolate at the bottom of the picture (b).  The sharpness of corners and the finer details are due to the presence of beta crystals, which stack due to their shape. If good temperature control is used, backfilling allows the chocolatier to get double, triple, or even greater capacity from a system.

There are three basic parameters that can be controlled to maintain flow properties while increasing capacity.  These parameters are batch temperature, dilution rate, and dilutant chocolate temperature. Batch temperature is the temperature of the chocolate is brought to just prior to using the chocolate. Dilution rate is the percentage of melted unseeded chocolate that is added back to the seeded/tempered chocolate. Dilution frequency is the amount of time between the adding back of the unseeded chocolate. This rate is subject to the overall thickening rate of the chocolate with more frequent additions being preferred to adding to thicker chocolate because the thicker the chocolate the harder to get a homogeneous mix. The unseeded chocolate temperature will determine how many crystals are melted verses how many crystals are diluted. The key is to keep the overall temperature to less than 91°F (33°C), as this ensures not too many crystals are melted out. However, the target temperature is a moving target that changes with the recipe of the chocolate, depending on the number and size of crystals in the chocolate, and can range from 86°F to 92°F (30°C to 33°C).

Creating Initial Temper

Chocolate can be tempered using any traditionally seeded chocolate method. However, only part of the complete mass should be seeded. The rest should be fully melted and then brought to the backfill temperature and held there. In general, it is quicker and easier to heat than to cool a chocolate. Some methods that can be used to quickly heat a chocolate include a hot air gun, dehydrator, water bath, heat lamp, etc. To keep a homogenous mixture, ensure that the chocolate is evenly heated and scraped from the sides of the container.

Typical Tempering Cycle

1. Melt all chocolate required for the production session.

2. Cool all chocolate to a temperature between 93°F and 95°F (34°C and 35°C).

3. Remove the desired amount of melted chocolate to be added back to the seeded chocolate over time, and hold at desired temperature.

4. Temper a usable amount of chocolate using any traditional seed addition or slabbing tempering method.

5. Run a temper check.

6. Use the chocolate while reheating to maintain it at a usable thickness.

Backfill Sequence

Initiate a backfill sequence when the chocolate becomes too thick for purpose of use or is about 50% of the initial amount of chocolate tempered as measured by volume or weight. Note that adding chocolate back at greater than the 50% quantity increases the risk of burning or diluting out too many crystals.

1. Slowly add back unseeded chocolate that is between the temperature range of 91°F and 94°F (33°C and 34°C). Make sure the tempered chocolate temperature stays at less than 90°F (32°C) and preferably within 1 to 2 degrees F. of the temperature of the last batch of usable tempered chocolate. Note this temperature changes over time and in general must be increased as the chocolate thickens.

2. Mix the newly created mass until a homogenous mix is acquired.

3. Run a temper check and, if acceptable, continue production.

4. This sequence can be performed as many times as necessary to complete the production run.

Comments

A well-tempered mass can be maintained in a usable flow state for a long period of time with the backfilling of unseeded chocolate. Actual required flow properties will depend on the product being produced, and needs to be determined for each project using such observable characteristics such as chocolate to center ratio, flow of a chocolate into corners of a mold cavity, ease of air bubble removal, foot formation on dipped items, etc.

Actual temperatures for a project will vary due to the wide variety of chocolate formulae available. The reason for this is that the more competitive fat in a formula, the harder it is for the chocolate to form beta crystals, and the easier it is for the beta crystals to melt out. This is seen in the traditional tempering system, and simply means that a milk chocolate tempered mass will have a lower add-back temperature than a dark chocolate with no or very little competitive fat. With a very high-fat chocolate, over-temper will be seen more in a dulling of the chocolate and the formation of small air bubbles than the thickening of the chocolate.

Conclusion

The bottom line is that backfilling with unseeded chocolate is a low-cost method for both expanding capacity and controlling the thickening of a chocolate, and once project appropriate temperatures and add-back frequencies are figured out, one can expect repeatable results. As such, it is a great tool to have when you need more production capacity, but can’t justify the cost or don’t have the space for a larger unit.

(This article appeared in the Summer 2023 issue of Pastry Arts Magazine)

About Dennis Teets

Dennis Teets has worked in the confectionery industry for both large and small organizations for over 30 years. During that time, he was both a problem solver and a new product developer. Today, Dennis works as a coach and consultant for small to medium chocolate companies, focusing on growth, scale-up and problem-solving. His email is
[email protected].