culinary math

What is Culinary Math, Measuring Systems, Recipe Conversion, Calculations, Trim and Waste

Examples include counting portions, increasing a recipe yield, determining a ratio for preparing a stock, calculating a plate cost, or establishing a food and labor budget. Culinary math begins with the basics of addition, subtraction, multiplication, and division along with ratios, yields, and percentages. 

The US measurement system is based on ounces and pounds for weight, and cups, quarts, and gallons for volume measurement. While length is measured in inches, feet, and miles, temperatures are scaled according to the Fahrenheit system using 32° as the freezing point for water and 212° as its boiling point. 

However, most of the world uses the metric system that measures quantities for weight, volume, and length in multiples of 10, 100, or 1000. Volume is based on liters and milliliters, weight is measured in grams and kilograms, and length is measured in millimeters and meters. Temperatures are calculated using Celsius which is based on 0-100° representing the freezing point and boiling point of water respectively.

Learn the universal abbreviations for measurements.

Be familiar with common conversions between cups, pints, quarts, and gallons.

Memorize how many ounces are in a pound, half-pound, or quarter-pound.

Understand the difference between a dry measure and a liquid measure.

Master basic conversions between weight and volume for select ingredients (liquids, dry ingredients). For example, a cup of flour weighs about half as much as a cup of water.

Recipes often need to be increased or decreased in quantity for a specific production requirement. There are ways to increase a recipe by simple multiples, double or triple, for example, or to decrease a recipe by dividing it in half. When a recipe needs to be converted into an odd size, like an increase of 40% or a decrease of 20%, it is better to determine a Recipe Conversion Factor (RCF). 

Measurements often need converting back and forth from larger units to smaller ones when scaling recipes or when determining purchase quantities based on edible portion size. Remember it is easier working with smaller units than with larger units. 

Buying minimally processed fresh produce, meats, fish, and seafood often requires trimming, fabricating, and portioning food. Foods purchased in this state are often called the As-Purchased (AP) or As-Purchased Quantity (APQ). Because the yield will vary on food items, a reference guide such as The Book of Yields is a great tool to assist in purchasing decisions. In-house yield tests should be done because products will vary depending on their size, quality, type of crop, the growing season, and regional differences. If you are purchasing locally sourced food, uniformity is even less predictable, so conducting edible portion yield tests is a good idea.

Once a product is cleaned, trimmed, and portioned it is called the Edible Portion (EP) or Edible Portion Quantity (EPQ). The EP is important because it reflects the true quantity needed and the true cost of the food.

The edible portion is the yield after the product is trimmed for use. Begin by weighing the product before cleaning. Trim, fabricate, and portion the product. Weigh the edible portion and divide it by the AP weight. This will give you a percentage.

Formula
EP weight/AP weight = EP percentage (%)

Example
Green Beans – 4 Lb. EP/5 Lb. AP = 80% EP Yield.

Food purchasing often requires AP calculations based on EP yield.  If 80 - 4 oz. portions are desired with a product yield of 70%, the formula would look like this:

Formula Example

EPQ/Yield Percentage = APQ.

Portion Size X Number of Portions = Total EPQ needed.

4 oz. portions X 80 portions = 320 oz.

320 oz. / 16 oz. (amount in 1 Lb.) = 20 Lb.

20 Lb. /.70 (70%) = 28.6 Lb.

Round up to 30 Lb.

Culinary math and costing are essential skills for any chef or food service manager. They help you plan menus, control costs, reduce waste, and ensure profitability. But how can you teach these skills effectively to your culinary students or staff? Here are some tips and strategies to make culinary math and costing fun, practical, and relevant. 

One of the best ways to teach culinary math and costing is to use real-life examples that your students or staff can relate to. For example, you can use recipes, invoices, menus, inventory lists, or food labels from your own kitchen or business. You can also use online tools, apps, or calculators that simulate common scenarios or problems. By using real-life examples, you can show how culinary math and costing apply to everyday situations and decisions, and how they affect the quality, quantity, and profitability of food. 

Before you dive into the calculations, make sure you explain the concepts and formulas behind culinary math and costing. For example, you can explain what are the different types of measurements, conversions, yields, portions, costs, markups, margins, and breakeven points. You can also explain how to use formulas to calculate these values, and how to check your work for accuracy and consistency. By explaining the concepts and formulas, you can help your students or staff understand the logic and purpose of culinary math and costing, and how to apply them correctly and confidently.