One of the first tips a person should consider when tempering chocolate is to pay attention to how it is stored, because storage can affect how well chocolate can be tempered. Chocolate is sensitive to heat and temperatures have to be monitored carefully, and a chocolate thermometer or regular kitchen thermometer can help with this. High humidity can negatively affect the tempering process, because moisture can cause chocolate to seize. The thickness of the tempered chocolate also can change the appearance of the final product. Using a marble slab to help cool the melted chocolate also can aid in the tempering process, though it's not necessary.
How chocolate is stored is important when one is planning to temper it. Refrigerators are too cold for storing chocolate; the ideal temperature will fall within a narrow range of 55° to 60° Fahrenheit (13° to 15° Celsius) in a cool, dry, dark place. It should be wrapped in foil and plastic.
It also should be kept away from strong smells, which can be absorbed by chocolate and will spoil it. If storage conditions are perfect, white and milk chocolate will stay fresh for up to eight months while dark or unsweetened chocolate will stay fresh for up to 10 years. Chocolate that is not stored properly can develop gray-white spots called fat blooms or rough patches called sugar blooms, which disappear with tempering but can affect candy making.
It is best to work at room temperature, around 68° to 70° F (20°-22° C) when tempering chocolate. Humidity also is an important consideration when tempering chocolate. The relative humidity of the room in which the tempering will be done should be 50 percent or lower. The lower the humidity, the better the tempering process will work.
Moisture is the enemy when tempering chocolate. A tiny amount of water is enough to cause the chocolate to seize, which will ruin the tempering process. Everything used should be dry, including the chocolate. Condensation will form on chocolate that is more than 17° F (10° C) colder than the room once it is exposed to warmer temperatures. Surface moisture should not be allowed to settle on the chocolate.
A melting temperature of 109° F (43° C) will allow most kinds of chocolate to temper perfectly, though some manufacturers recommend a higher melting temperature when tempering chocolate. Temperatures above 130° F (54° C) will cause the chocolate to scorch or seize. Tempered chocolate should be held at a temperature of 85° to 88° F (29°-31° C) to use it. When it comes time to let the chocolate cool, it can remain in the bowl in which it was melted, as long as one stirs the liquid as it cools. It also can be poured onto a marble slab, or tempering stone, and stirred or scraped around the surface until cool.
When tempering chocolate, close attention should be paid to its viscosity. Chocolate that is runny will make a thin coating, while thick chocolate will create a thick coating. If the chocolate is too thick, then adding cocoa butter will thin it. Adding more chocolate will help to thicken it if it is too thin.