Ever since culinary school, I have had one formula stuck in my head: how to reduce a recipe. You take what you need and divide it by what you have to get your conversion factor, and then multiply all the ingredients by the conversion factor to get the new recipe measurements.
I vaguely remember learning another, more difficult formula in culinary school that was more precise…or rather, I remember trying to learn it but failing miserably and assuming the one I had memorized would do me fine.
Then I tried to reduce a baking recipe and got the bread that ate Chicago.
You see, the conversion method I was using did not account for the weight of the ingredients and making sure that balance was still there when the quantities were increased or reduced–after all, baking is nothing but a giant science experiment.
So I decided it was time to dust off the old culinary math book and see if after earning three degrees, I could finally conquer the proper recipe conversion method. I used Food and Beverage Cost Control by Miller, Hayes and Dopson, Second Edition, pp. 61-63. They call this the percentage method. I don’t disagree.
Oh, and it helps to use a published guide for ingredient weight conversion, something that gives exact weights for flour, sugar, and other common baking products (I used my Baking book from culinary school for this). A lot of internet guides will vary on their weights, and that makes for a messed up recipe in the end.
5 steps to PROPER recipe conversion via the percentage method:
- Figure out the total weight of the recipe and convert to ounces
- Figure out the percentage of each ingredient by dividing it by the total original recipe weight.
- Figure out the portion size, and how many portions the recipe makes.
- Take the number of portions you need and multiply it by the serving size to get your new recipe weight needed.
- To receive the new recipe measurements, multiply the % total of the ingredient item by the total new recipe weight needed.
I know, it sounds like it might take forever, but I promise, with some dilligent work and a calculator, you’ll be fine, and what’s more–you’ll have a properly altered recipe.
Let’s practice with this recipe:
- Original Recipe for Pudding:
3 qt. heavy cream
3 qt. half n half
5 cups sugar
8 T cornstarch
2 # dark choc. Chips
4 T butter
- Recipe weight in ounces:
96 oz heavy cream
96 oz half n half
16.94 oz. egg yolks
44 oz sugar
32 oz chocolate
2 2/3 oz cornstarch
Total weight: 289.6 oz
- Figure out what percentage of the total weight each ingredient is:
Need 6 servings= 24 oz
- Convert recipe:
33.1% x24 = 7.94 oz
33.1% x24 = 7.94 oz
5.8% x24= 1.39oz yolks
15.2% x24= 3.65oz sugar
11% x24= 2.64oz chocolate
1% x24= .24 oz butter
1% x24= .24oz cornstarch
- New recipe
7.94 oz heavy cream
7.94 half n half
3.65 oz sugar
.24 oz cornstarch
I’m no math whiz, and I’ve had my husband check my math on most recipes, but so far, I’ve had success with this method. Let me know if you have any questions…will do my best to answer!