As I said in Temper Tantrum Part One (below), instructions for tempering chocolate are usually brief and deceptively easy looking.  As a result, many people find tempering to be completely frustrating.  I hope the following not-so-brief notes and instructions adapted from my book, Seriously Bittersweet (Artisan, 20130) will help.  Even if you prefer to use a tempering method other than The Chunk Method described, the information that follows it—The Test For Temper, Keeping Tempered Chocolate in Working Condition, and How To Fix Over Tempered/Over Seeded Chocolate—is essential if you want order to avoid the heartbreak of grey or streaky confections, after all of your time and effort! 

Just A Few More Things to Keep in Mind before you jump in

A piece of tempered chocolate has a shiny reflective surface (unless it has been scuffed or jumbled with other pieces of chocolate) and an even interior color and texture. It is brittle enough to snap audibly when broken or bitten.  Melted chocolate that has been tempered shrinks slightly as it cools and so it releases perfectly from molds, and mirrors any surface with which it has been in contact: tempered chocolate poured into a mold with a shiny surface will emerge shiny.  Any bar or piece of chocolate that you buy was tempered at the factory and, unless it has been damaged by heat in transit or in storage, and will still be tempered when you unwrap it to eat or cook with.

Heat-damaged chocolate or chocolate that has melted and cooled at room temperature without being tempered again looks dull and gray, perhaps mottled or streaky.  It may be soft and cakey at first, but it will eventually become dry and gritty with a stratified interior texture. When that happens the chocolate actually tastes less flavorful and melts less smoothly in your mouth.

Whether in perfect temper or out of temper to start with, each time chocolate is melted, it must be tempered in order for it to cool and set at room temperature with a glossy surface and crisp texture. Chocolate can be melted and tempered over and over again.  

There is no need to temper melted chocolate used as an ingredient in a batter or dessert, sauce, or glaze.  However, if you want to dip cookies in chocolate that will dry hard and glossy, or if you want to make a molded chocolate rabbit, or if you want dipped chocolates (or pretzels) to dry beautifully and keep at room temperature, you must temper the chocolate.

Melted chocolate solidifies as it cools because the fat molecules link together and form crystals that connect to form a sturdy network. Cocoa butter is a complex fat capable of taken different crystal forms, but only one of the forms is stable and will cause the chocolate to contract and harden with the desired shiny surface and brittle snap.  This stable form is called beta. It takes only a small percentage of beta crystals in melted chocolate, to ensure that subsequent crystals will also take the beta form as the chocolate cools. The process of tempering involves a sequence of heating, cooling, and stirring steps designed to produce just enough beta crystals to set the pattern for the rest of the crystals that will form as the chocolate cools.

Under the right conditions, beta crystals form and survive at temperatures between 82°F and 91°F; they melt and are destroyed at higher temperatures.  Most tempering methods involve heating the chocolate well above 91°F so that all crystals (stable and unstable) are melted and destroyed so that you start with a kind of crystal-free blank slate.  Then, as the chocolate cools, you create brand-new beta crystals.  Once there are enough beta crystals, the chocolate is tempered.  Since you cannot see the crystals (alas), you can use a simple test to determine whether enough crystals have formed, thus whether the chocolate is in temper. 

And A Few Tips Before You Start

Keep this mantra in mind: Tempering is not simply a matter of taking chocolate from one prescribed temperature to another, even though most instruction focuses mostly on that activity. Tempering is a function of three interrelated factors: time, temperature, and agitation (stirring). This means that your chocolate may not be in temper the moment you have completed the steps to get your chocolate to the “correct” temperature. Often, the chocolate just needs a few more minutes of stirring.  Do not get so involved with temperature that you forget the necessity for time and stirring.  Use the test for temper as feedback as you work, and be prepared to practice, go slow, observe, and adjust (Zen and the art of chocolate tempering).

It’s best to temper more chocolate than you need for a recipe or dipping project.  A large bowl of tempered chocolate is easier to keep warm and in good working condition than a small one and any chocolate left over can be saved for reuse. I like to work with at least 1 ¼ pounds (565 grams) of chocolate, but you can temper any amount you like using the following guidelines:

-Use real chocolate (not compound coatings) but not chocolate chips

-Do not work in a hot room

-Don’t allow moisture to come in direct contact with the chocolate: make sure that the knife, cutting board, bowl, spatula, and thermometer stem are all clean and dry.  If you are dipping fruit, the fruit should be dry as well.

-Before tempering, prepare whatever is to be dipped and/or measure out any other ingredients needed (and have them at room temperature because cool or cold centers will cause the chocolate to crack when it cools) so that your tempered chocolate can be used immediately.

-Have a cool place to set trays of dipped items:  I set mine in front of a portable table fan (after anchoring the corners of the parchment or wax paper liners with tape).

-Last but not least, no one said tempering doesn’t take practice!

FINALLY: THE CHUNK METHOD FOR TEMPERING CHOCOLATE  

This method requires that 20% (one fifth) of the chocolate you start with be solid chocolate that is already in temper —and in one or two large chunks instead of chopped.  The remaining chocolate may be in temper or not.

You will need an instant read thermometer, or a chocolate thermometer

1. Set aside 20% of your chocolate for “seed”: the seed should be one or two large chunks and already in temper.

2. Chop the remaining chocolate into small pieces and place them in a stainless steel bowl large enough for thorough stirring. Set the bowl in a wider skillet of almost simmering water and stir frequently at first, and then constantly until about three-quarters of the chocolate is melted.  Remove the bowl from the water and stir for a minute or two to melt the remaining chocolate.  If the chocolate is not entirely melted put it back in the water and continue to stir briefly.  The goal is completely melted chocolate at about 100°F (if it was in temper to start with) or at 120°F (if it was not in temper).  If the chocolate exceeds these temperatures, don’t worry; just let it cool to 100° before proceeding.

3. When the chocolate is at 100°F, drop the reserved chunk(s) of tempered chocolate into the bowl and stir constantly, pushing the chunks around the bowl and scraping the sides of the bowl regularly, until the chocolate registers 90°F for dark chocolate or 88°F for white or milk chocolate. As you stir, you are simultaneously cooling the chocolate and melting the surface of the tempered chunks. As the temperature of the melted chocolate approaches 90°F, stable beta crystals from the surface of the chunks start to mingle with the melted chocolate and form the “seed” to create more beta crystals.  When there are enough beta crystals in the bowl, the chocolate is tempered. The object is not to melt the chunks entirely, but to use them to provide the beta “seed” to produce more beta crystals, and then fish out and save the chunks for another project.  In fact, if your chunks are completely melted by the time the chocolate reaches 90°F, the necessary beta crystals are likely to have been destroyed; you may have to add another chunk and continue to stir.

When the chocolate is at the desired temperature (90°F or 88°F), it may or may not yet contain enough beta crystals to be tempered.  Use the Test for Temper (see below) to be sure. If the chocolate is not in temper, continue to stir for a minute or two longer then test again.  As soon as the chocolate is in temper, remove the unmelted chunk(s) and chill them in the fridge for 10 minutes then store at room temperature to be used again. Use the tempered chocolate immediately.

THE TEST FOR TEMPER

Never assume your chocolate is in temper, or use it,  without testing it:  Drizzle a little of the chocolate onto a knife blade or a piece of wax paper. Set the test in front of a fan (preferably) or in a cool place. If the chocolate is beginning to set within 3 minutes and it has a nice sheen, it is tempered. If it is still completely melted and wet looking after 3 minutes, it is not yet tempered. (If it has begun to set but looks dull, it may be over tempered, see How To Fix Over Tempered/Over Seeded Chocolate, below).

KEEPING TEMPERED CHOCOLATE IN WORKING CONDITION

If you are using the tempered chocolate for dipping, stir it from time to time and scrape down the bowl to prevent chocolate from building up around the sides. The chocolate will cool and thicken as you work.  You can rewarm the chocolate in a pan of warm water for a few seconds at a time, or warm the sides of the bowl with a hair dryer, and stir until the chocolate regains fluidity as long as you do not let it exceed a maximum temperature of 90°F or 91°F for dark chocolate or 88°F to 89°F for milk and white chocolate.  Or, to keep the chocolate warm longer, you can keep the bowl of chocolate in a container of warm water just 2 degrees warmer than the maximum temperature for the type of chocolate you are using. Or set the bowl on a heating pad covered with several layers of two so that it is barely warm.

But tempered chocolate will thicken over tine as you work with it, even if it is kept at or reheated to its maximum temperature.  This means that too many beta crystals have developed: the chocolate is over seeded or over tempered

HOW TO FIX OVER TEMPERED/OVER SEEDED CHOCOLATE

Tempered chocolate thickens as you work with it.  Intuitively, it would seem that the thickening is due to cooling, but that is only partially true.  In the course of dipping centers (or whatever), re stirring the chocolate and scraping the bowl from time to time, tempered chocolate will thicken even if it is kept at its warmest “ceiling temperature”.  Why? Remember that the formation of beta crystals necessary for tempering the chocolate required time and agitation in addition to the right temperature.  Once the chocolate is in temper, time and agitation (that is, dipping and scraping the bowl and restirring the chocolate) continues to create more beta crystals, whether or not you want them.  More beta crystals make the chocolate thicker and harder to work with.  The chocolate is still in temper but it is overtempered or over seeded:  it will set even faster than before and with a duller finish.

The fix? If the chocolate is at or close to its ceiling temperature, but still too thick, you must melt and destroy some of the excess beta crystals by allowing some of the chocolate to exceed the maximum temperature.  Set the bowl in the water bath for a few seconds as before, but without stirring so that the chocolate around the sides of the bowl gets warmer than the rest. Then remove the bowl from the water and stir the chocolate thoroughly to mix in the warmer chocolate.  This should return your chocolate to a more fluid and, with luck, still tempered state. If it’s not fluid enough, set it in the water for a few more seconds, then remove and stir well.  After this maneuver, always test for temper again to make sure that you haven’t melted too many of the beta crystals and lost the temper of your whole batch.

Anther way to fix over seeded chocolate is to add a little “virgin” chocolate* to the thick chocolate and stir it in thoroughly.  This re-warms the chocolate, reduces the ratio of tempered crystals and puts you back in business

*Virgin chocolate=chocolate that has been heated to 125°F and then cooled to 92°F to 90°F without tempering.