Egg

Eggs are frequently used as a binding agent in period recipes. While redacting, you should keep in mind that eggs were smaller during period, and adjust the number of eggs accordingly. All sorts of eggs can be used in cooking, although the cholesterol content, and egg white:egg yolk ratio may vary depending on the egg. Duck and goose eggs are much larger than chicken eggs, and there is more yolk in them, so often on large duck or goose egg is equivalent to two small chicken eggs.

Eggs were also used as period hydrometers while brewing. The amount of egg visible above the liquid determined the density.

You can tell if an egg has gone rotten by placing it in a bowl of water: if it floats it is bad, if it sinks it is good. This is because when the egg starts to go off, a biproduct of this is gas which remains trapped in the egg, and thus it floats.