Tempering Chocolate

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About
The tempering process consists of three basic steps: heating the chocolate to thoroughly melt all of its fat crystals, cooling it somewhat to form a new set of starter crystals, and carefully heating it again to melt the unstable crystals, so that only desirable stable crystals remain. The stable starter crystals will then direct the development of the dense, hard crystal network when the chocolate finally cools and solidifies.

Unstable cocoa butter crystals are crystals that melt relatively easily, which means at relatively cool temperatures, between about 59 and 82°F/15–28°C. The desirable stable crystals (sometimes referred to as “beta” or “beta prime” or “Form V” crystals) melt only at warmer temperatures, between 89 and 93°F/32–34°C. The temperature range in which a particular kind of crystal melts is also the range in which it forms as the chocolate cools. Unstable crystals therefore form when molten chocolate is cooled rapidly, so that the stable crystal types—the ones that begin to form at warmer temperatures—don’t have time to gather most of the fat molecules to themselves before the unstable crystals begin to form. Stable crystals predominate in melted chocolate when the cook carefully holds it at temperatures above the melting point of the unstable crystals, but below the melting point of the stable crystals. This tempering range is 88–90°F/31–32°C for dark chocolate, somewhat lower for milk and white chocolates thanks to their mixture of cocoa and milk fats.