Cocoa
The usual rule is 2 teaspoons cocoa, 1 teaspoon sugar; 1 tablespoon cold water and 3/4 cup milk to each cup. Mix dry cocoa with sugar and cold water; cook over slow fire until thick; add milk, and boil 1 minute.
A per-cup formula rather than a batch recipe, and it works as written. The only thing that needs attention is the paste stage, which is what separates this from stirring cocoa into hot milk and getting lumps.
- Make the paste properlyThe cocoa, sugar and cold water must be cooked into a smooth, glossy paste before any milk goes in. This hydrates the starch in the cocoa and disperses the fat, which is why the finished drink is smooth rather than gritty with floating powder.
- "Slow fire"Low heat on a modern burner. The paste stage takes a minute or two of constant stirring and thickens suddenly; a hot pan scorches the sugar and the cocoa turns bitter.
- Cocoa means unsweetened powderThis is plain cocoa powder, not drinking chocolate or a sweetened mix. Natural (non-alkalized) cocoa was the more usual household choice in books of this kind, and gives a sharper, fruitier cup than Dutch-process, which will taste rounder and darker.
- Scale as writtenTwo teaspoons cocoa, one teaspoon sugar, one tablespoon cold water and 3/4 cup milk per serving. For four cups: 8 tsp cocoa, 4 tsp sugar, 1/4 cup water, 3 cups milk.
- The one-minute boilBring it just to a boil and hold it briefly, no longer. Milk held at a boil forms skin, catches on the pan bottom and takes on a cooked flavour. Whisking at the end raises a little foam and keeps the skin from setting.
- SweetnessOne teaspoon of sugar per cup is restrained by current taste. Taste the paste before the milk goes in and adjust then, while the sugar can still dissolve fully.
Cocoa in a book like this is the temperate, everyday cousin of chocolate: cocoa powder is what remains after most of the cocoa butter is pressed out of the ground bean, a process generally traced to the Van Houten press in the Netherlands in the 1820s, which made a cheap powder possible for ordinary households. By the time cook books of this kind appeared, cocoa was firmly a breakfast and nursery drink, promoted as nourishing and free of the objections raised against tea and coffee, and it sat in the beverage chapter alongside them as a matter of course. The paste-first method exists purely because cocoa powder will not wet out evenly in hot milk.