I’ve been short of time for my regular historical research projects, but I have two large bags of apples and went through my pamphlets in search of recipes. While I was at it, I decided to look into the baking powder question, when has been troubling me since my Davis Baking Powder layer cake came out terribly flat a couple of months ago. It’s clear from reading these things that the companies used different formulas for their baking powders, which might be different from modern baking powder.
So here are the results of my investigation, based on looking at the basic baking powder biscuit recipe in each of the five (!) baking powder company recipe booklets that I have:
Larkin (1907) – 1-1/2 tsp. : 1 cup flour
Ryzon (1918) – 2 tsp. : 1 cup flour
ETA Calumet (1931) – 1 tsp. : 1 cup flour
Royal (1932) – 2 tsp. : 1 cup flour
Rumford (1938) – 1 tsp. : 1 cup flour
Davis (1940) – 1 tsp. : 1 cup flour
Modern recipe: 2 tsp. : 1 cup flour
So there we have it. The Davis cookbook called for half the amount of baking powder that’s required with modern (standardized) baking powder. No wonder I wound up with three cake Frisbees instead of three nice cake layers!
It’s important, then, to examine each vintage recipe and determine what ratio of baking powder to flour it assumes. Modern baking powder requires 2:1. And given any uncertainty, I’d opt for putting in a bit more rather than a bit less.