Cocoa butter is the fat in the cacao bean that gives chocolate its unique mouth-feel and stable properties. To be considered “real” chocolate, a chocolate bar or chunk can contain only cocoa butter, not any other fat. Cocoa butter is the reason why you have to “temper” real chocolate.
Cocoa butter is fat that is composed of three to four glycerides of fatty acids. What complicates matters in chocolate making is that each of these different fatty acids solidifies at a different temperature. Once you melt a chocolate bar, the fatty acid crystals separate. The objective in tempering melted chocolate is to entice the disparate fatty acid crystals of cocoa butter back into one stable form.
Tempering is like organizing individual dancers at a party into a Conga line. For chocolate, temperature and motion are the party organizers that bring all the individual dancing crystals of fatty acids together in long lines and, in the process, create a stable crystallization throughout the chocolate mass.
Also, strange as it may sound, the temperature at which well-tempered chocolate melts is much higher than untempered chocolate because the fatty acid crystals in tempered chocolate are locked together tightly—it takes a higher temperature to pull them apart. Being tightly bound, well-tempered chocolate is resistant to developing chocolate bloom—that whitish film, streaks or spots of cocoa butter that form on the surface of chocolate.
In the tempering process, melted chocolate is first cooled, causing the fatty acid crystals to form nuclei around which the other fatty acids will crystallize. Once the crystals connect, the temperature is then raised to keep them from solidifying.
To help the chocolate to crystallize during the tempering process, chocolate makers use one technique called seeding. The "seed" is tempered chocolate in hunks, wafers or grated bits. It is added at the beginning of the tempering process. These crystals of tempered chocolate act like magnets, attracting the other loose crystals of fatty acids to begin the crystallization process that results in well-tempered chocolate.
Learning to Temper Real Chocolate
"Tempering by Seeding" is the easiest and quickest way to temper chocolate. You will need: Microwave (or double boiler), microwave-safe bowl, spatula for stirring and a good thermometer that has a range as low as 70° F (21° C).
I suggest you have at least 24 ounces (680 grams) of chocolate when you start to temper. I know it sounds like a lot, and a big monetary commitment, but this amount gives you enough to work with when you are dipping or molding.
Also, it is much easier to control temperatures and not overheat when you have a mass of chocolate. You can re-temper or reuse any of the chocolate you have left over, so the extra won’t be wasted. At my former shop, "au Chocolat," we sold our bulk chocolate in one-pound (454 g) round bars so I could easily show that a one-pound (16 oz.) puddle of melted chocolate only came up about an inch in the bowl. That is not a lot of chocolate mass in which to dip something.
Step 1. You need to heat the chocolate to melt all fatty acid crystals.
Chop the chocolate into small pieces. The smaller the pieces, the quicker your chocolate will melt and temper. Set aside about 25 to 30 percent of the chocolate. There is no need to be exact on this measurement, as you just want enough unmelted, tempered chocolate to start the seeding process.
Place the remaining 70 to 75 percent of chopped chocolate in a microwave-safe bowl and microwave on half-power, being very careful to stir the mixture every minute until it is almost completely melted, which should take about four to five minutes.
Remove the bowl of chocolate from the microwave and stir to cool it slightly. Removing the bowl before all the chocolate is completely melted will help prevent over heating. You don’t want your chocolate to burn. Those last bits of solid chocolate will melt as you stir. Using a thermometer, check the temperature of the melted chocolate—it should be between:
I’ve indicated a range of temperatures above as not all thermometers are perfectly accurate.
Step 2. Add the seed chocolate you have set aside.
Start adding handfuls of the grated chocolate you set aside to the melted chocolate. Stir in the seeding chocolate bits continuously until the desired temperature (see below) is reached and the bits have dissolved completely. This could take anywhere from 10 to 15 minutes, depending on the temperature of your environment. Your chocolate should now be tempered.
Make sure to stir the tempered chocolate and check the temperature during the time you are using it for dipping or molding. You can put the tempered chocolate mass in the microwave for 10 – 15 seconds at half-power if the temperature starts to drop. Just make sure that you don’t raise the temperature above 90° F (32° C) or you will lose your temper and have to start over again at Step 1.
A heating pad put around the bottom and sides of the bowl will help if you are doing a lot of work at one time. Again, make sure the heating pad doesn’t raise the temperature of the chocolate too high. Keep stirring and checking the chocolate mass with a thermometer.
About Chocolate Seize
This is when your melted chocolate mass becomes a paste that is grainy, dull, and thick. There are two conditions that bring about chocolate seize:
Chocolate is made up of dry ingredients (cocoa solids, sugar, and possibly milk powder) suspended in cocoa butter. A small drop of liquid will moisten the dry ingredients and allow the cocoa solids to clump together and separate from the cocoa butter. Remember the old saying that oil and water don't mix? This is why you never cover a pot of chocolate with a lid (because the steam will condense and drop into the chocolate) and why you need to be very careful when using a double boiler. If this happens, the chocolate will not temper, but it doesn’t have to go to waste; it can be used in baking or truffle centers.
Interestingly, if you add in more liquid to the chocolate (a minimum of one tablespoon of liquid per ounce of chocolate), the melted chocolate will remain in a liquid state because the dry particles get saturated by the moisture and detach from each other. They then are suspended in the liquid again so the chocolate mass is back to a liquid form. You'll find this technique used to make chocolate sauces and syrups or for flavoring cakes and pastries.
Overheating separates the cocoa solids and other dry ingredients from the cocoa butter. Chocolate solids and dry ingredients will burn if heated to 130 degrees. The result is a dry, discolored paste. There’s no retrieving burnt chocolate, so be very careful when heating in a double boiler or microwave.
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