Cooking and math are two of my favorite subjects. When I get a chance to combine the two it’s a good day for this foodie / math nerd. Most of my fellow culinary students did not like this lesson but I loved it and found that it really helped me in preparing for catering jobs.
This week we learned how to convert recipes. Increasing a recipe by a nice, whole number is easy — just multiply by that nice, whole number.
Example: A recipe serves 4 and calls for 2 cups of chicken broth. I need to double that recipe to serve 8 so I multiply the 2 cups of chicken broth by 2 which means I will need 4 cups of chicken broth to serve 8 people. (2 cups x 2 = 4 cups)
But if you need to decrease a recipe, it turns into a fraction problem. For instance, if I need 3/4 of a recipe, I would multiply all the ingredient amounts by 0.75.
Example: A recipe serves 20 people and calls for 10 pounds of chicken. I need to reduce the amount of chicken to serve 11 people. 10 pounds of chicken times 0.75 equals 7 1/2 pounds of chicken to serve 11 people. (10 pounds x 0.75 = 7.5 pounds)
Probably the most complicated conversion is called the “conversion factor.” The conversion factor is directly related to the yield of a recipe. If a recipe yields 75 servings and I need it to yield 58 servings, I would divide the 58 servings I need by the 75 servings the recipe calls for. The number result is 0.77 which is my conversion factor. I would then multiply all the ingredient amounts by the conversion factor.
Example: A recipe for pasta that serves 75 and calls for 12 pounds of pasta would need to be converted down to serve 58. That means I multiply 12 pounds of pasta called for by the 0.77 conversion factor which results in 9.24 pounds of pasta needed to serve 58. (12 pounds x 0.77 = 9.24 pounds)