Melt a chocolate bar and let it set, and it often comes out dull, soft and streaky. Tempering keeps it shiny and crisp.
Key idea
Cocoa butter can set in several crystal forms; only one is stable, shiny and snaps cleanly. Tempering controls the temperature so that form wins: melt completely, cool while stirring so stable crystals start to form, then rewarm slightly to melt any unstable ones, and hold at the working temperature. Typical working temperatures are about 88°F to 90°F for dark chocolate, 86°F to 88°F for milk and 82°F to 84°F for white; makers print their own on the package, and those come first.
- Seeding method: melt two-thirds of the chocolate, then stir in the remaining third, finely chopped, to cool it and add stable crystals.
- Keep water and steam away: a few drops can make melted chocolate seize into a thick paste.
- Test: smear a little on foil or a knife tip; tempered chocolate sets shiny and firm in a few minutes at cool room temperature.
- Store finished chocolate cool and dry, not in the refrigerator, where moisture can bloom on it.
Why it works
Untempered chocolate sets with a mix of unstable crystals, which melt at lower temperatures and let fat rise to the surface as gray streaks (fat bloom).
Worked example: Seeding
You have 600 g of chocolate for the seeding method (melt two-thirds). How much do you melt first?
- $600 \times \tfrac23 = 400$ g melted; 200 g chopped for seeding.
Answer: 400 g.
Common mistake
Covering melting chocolate with a lid over steam. Condensation drips in and it seizes.
Practice at home
- Temper 300 g of dark chocolate by seeding with an accurate thermometer. Dip strawberries or make bark, and leave one smear untempered to compare.
In Meal Prep
- Chocolate from cocoa powder and cocoa butter: with tempering
- Bean-to-bar chocolate: the whole process
- S'mores from Scratch: chocolate, marshmallows and graham crackers you make yourself