Baker's Percentage You'll often want to scale a recipe up or down. You can do this by multiplying the ingredient quantities by a given factor or by doing some division to figure out the ratios of the ingredients. The best system that we have found for making a recipe easy to scale is called baker's percentage, a method of measurement that is widely used in pastry and baking books. In a recipe that uses baker's percentage, one reference ingredient usually the ingredient that most affects the yield or the cost of the recipe-is set to 100%. The quantity of each other ingredient is then cited as a percentage of the reference ingredient's weight. For example, our recipe for Sous Vide Instant Hollandaise (see page 4-228) sets egg yolks as the reference ingredient at 100% and calls for 75 grams of yolks. It calls for vinegar at a scaling of 47%, meaning 47% of the weight of the egg yolks-not 47% of the yield or47% of the sum of all ingredients, just 47% of the weight of however much the yolks weigh. So if you're using 75 grams of egg yolks to make the recipe, you need 35 grams of vinegar, because 75 grams times 47% equals 35. But say you only have 65 grams of egg yolks. How much vinegar should you use? This is where the scaling percentage really simplifies things. Just multiply the same 4 7% for vinegar times the actual weight of egg yolks available-65 grams-to get the answer: 30.5 grams of vinegar. Keep in mind that the percentages of the minor ingredients will not add up to 100% because scaling percentages give the weight as a proportion of the VOLUM E 5 · PLATED ·D ISH REC I PES weight of the reference ingredient, not of the total weight of all ingredients in the recipe. One challenge in using baker's percentages is that they can be difficult to use if you want to omit or add an ingredient, or if you substitute several ingredients of different quantities. This issue comes up most frequently in recipes that involve small quantities of potent thickeners or gelling agents, but also for more common ingredients such as salt. In the hollandaise recipe, for example, if you decided to use a more flavorful wine and stock, you may choose to reduce it a bit less than the recipe calls for to achieve the balance of flavors you want. But how should you then adjust the quantity of egg yolks to preserve the texture of the sauce? We provide a special scaling percentage in many cases to help with such situations. A note at the bottom of the recipe explains how the special percentage is calculated. Often it is a proportion of the weight of all ingredients in the recipe or of all other ingredients (omitting the weight of the ingredient that has the special percentage listed). In the example above, we added the weights of the wine-shallot-vinegar reduction, the stock or water, and the butter, which came to about 268 grams when we made the recipe. The weight of the eggs, at 75 grams, is 28% of268 grams, so we include the 28% as a special scaling percentage. So, if in your adjustments to the recipe, you find that you end up with 300 grams of reduction, stock, and butter instead of the 268 grams we got, you can easily work out how much egg yolk to use by simply multiplying 300 grams by 28%: 84 grams of yolk should produce a texture very close to the original version. The special scaling sometimes becomes crucial when using recipes that include hydrocolloids that are quite powerful in small quantities, so must be added with great precision. Our recipe for a gelled Long Island Iced Tea on page 4·141, for example, suggests using 5.6% as much gelatin as you use of cola, thus 6.75 grams if using 120 grams of cola. But that ratio would not work well if you were to omit the tequila. In that case, you should instead use the special scaling listed for gelatin, which is 1.6% of the total weight of all the other ingredients, or 6.25 grams. Similarly, if you wanted to add, say, 60 grams of whiskey to the recipe, the special scaling percentage would let you easily work out the right amount.