How to Use a Recipe Conversion Factor (RCF)
Convert Your Favorite Recipes for Large and Small Crowds
Nov 12, 2008
Let's say you're hosting a Thanksgiving dinner party for your 22 in-laws and you really want to use your mother-in-law's special cranberry sauce recipe. The problem is, the recipe only yields 8 servings. Should you just triple the recipe and hope for the best? If you do that, you very well may not end up with the same taste and texture of the original recipe, not to mention you'll likely make too much and be stuck with cranberry sauce for the next three months.
Luckily you have all the information you need to convert your recipe quickly and accurately. Since you know you will need 22 servings and you know the original recipe makes enough for 8, you are halfway to the answer. But first, let's discuss what exactly the recipe conversion factor is.
The RCF
The recipe conversion factor, or RCF, is a number that is used to convert each ingredient quantity in a recipe to a new desired amount. The RCF is the best way to ensure that any alteration to an original recipe, be it larger or smaller, will not ruin the integrity of the dish.
To calculate the RCF, divide the new desired recipe amount by the old recipe amount. This decimal answer is the conversion factor. Note that this number will not have a unit attached to it; it stands alone. In the cranberry sauce example from above, the RCF would be 22 divided by 8, which equals 2.75. You would then multiply every ingredient in the recipe by 2.75 to get the correct amounts for the new recipe.
How to Find the RCF When There are Different Units
Now that Thanksgiving is over and your cranberry sauce went over so well with everyone, you've been asked to host a Christmas party for the entire family. . . all 56 of them. For this task you consult your newest Gourmet or Martha Stewart magazine with hopes of creating the perfect holiday menu. Unfortunately neither magazines' recipes yield quantities large enough to feed all 56 of your guests. So, you turn to your handy RCF for help.
You decide that your first course will be a lovely pumpkin soup. The recipe yields 4 quarts of soup, but you know you'll need 3 gallons. In this type of situation, in which the units are different (quarts and gallons), the calculation will be the same (new/old) but with one extra step: before calculating the RCF, it is necessary to make sure that the unit in the old recipe matches the unit in the new recipe.
For help with conversion, you can always check a conversion chart; in this case, the conversion is pretty simple: 4 quarts equals 1 gallon. Now that both recipe quantities are in the same units (gallons), you can calculate the RCF: 3 divided by 1, which equals 3. Then take each ingredient in the old recipe and multiply it by the RCF of 3 until you have all of your new amounts for the new larger recipe. It's as simple as that.
What to Watch out for when using the RCF
While the RCF is invaluable for the home chef when altering quantities of recipes, there are several things to keep in mind:
- If a recipe calls for a chemical leavener (like baking powder or baking soda) by volume, it is not recommended that you use the RCF. If, however, the recipe is in ounces (a weight measurement), the RCF should be reliable. Pay attention; volume vs. weight can be tricky.
- Many times small amounts of spices or other potent ingredients do not need to be altered and can remain appropriately apportioned at the original amount. For example, when doubling a paella recipe, you may find that the original amount of saffron listed is still potent enough for the larger yield. Ultimately, though, use your own palette to decide.
- The more you alter a recipe, be it up or down, the more likely you will run into a problem. Therefore, make sure to test your newly calculated recipe to see if further adjustments are needed.
Easy Trick for Remembering the RCF
The easiest way to remember the recipe conversion factor formula is as simple as NO . . . New recipe over Old recipe.
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