Food Truck Startup Journal Entry #13 — Why one of the most important lessons I learned in culinary school was math
The most impactful quote from my culinary school experience has been, “A bad kitchen manager will soon be an unemployed kitchen manager.”
It’s a quote that has been communicated by my different chef instructors of different disciplines at different times. It is as if these seasoned culinary professionals broke from a sports coaching huddle with an agreement to inadvertently leave their culinary athlete groups with a very important and often misunderstood point. When it comes to professional food service, your numbers matter and your stewardship of them has the power to heavily influence the trajectory of your career.
As I write this blog article I am wrapping up the last week of my Culinary Arts Certificate from the Culinary Institute of Charleston at Trident Tech in Charleston, SC. The certificate took 5 months (or a traditional semester) to complete. (Click here for more information on this great place of learning that at the time of this writing is currently offering free tuition — https://www.tridenttech.edu/academics/divisions/cic/) I am by no means an expert. However, I enjoy cooking and I have received the basics of how to excel within a professional kitchen.
For starters, before I elaborate on the math side of culinary education, here are a few non math related examples of what I learned this semester which were noteworthy. In my Kitchen Fundamentals class, we learned that there are five mother sauces (Bechamel, Veloute, Espangole, Tomato and Hollandaise) in which all other sauces are derived. Moreover, in my Intro to Culinary course I learned about the history of culinary and why the names like Auguste Escoffier, Edna Lewis, Kevin Mitchell and Alice Walters matter. Through the classroom training and passing the ServSafe test, I received my ServSafe Food Manager Certification. This certification helps my employment options and ability to understand the sanitary requirements of my own future food truck or restaurant. Each of the chef instructors emphasized the importance of punctuality and professionalism in a commercial kitchen. I am also grateful for the fact that I now have a diversity of accomplished and experienced mentor instructors that can give advice on future recipes and culinary opportunities.
However, the most impactful part of my culinary school experience has been an understanding of how math or numbers are used every day in a professional kitchen. In this blog article I will elaborate on six; 1. Measuring the internal temperature of prepared food, 2. The power of the “oz“ 3. The conversion factor, 4. Calculating yield percentage. 5. Establishing your food prices based on food cost 6. Learning your recipe cost by assessing your ingredients
- Measuring the internal temperature of prepared food
How do you know when your chicken is done? How about your steak? Or when your cooked eggs are done? While I think the five senses (touch, taste, smell, feel and taste) are very helpful aids, they are not objective measuring standards.
The proper way to assess whether your cooked food is ready to serve and or eat is to measure the item with a thermometer (typically called probe or instant read). When measuring their desired item the chef / cook will generally stick the middle of the equator of the widest (or fattest) part of the item. Cooking food to appropriate temperatures not only ensures the food is done, it also has been determined that this is the way to kill (or drastically reduce the amount of) the bacteria in the food.
For personal cooking in a home kitchen many people adhere to the USDA standard (seen here — https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/safe-temperature-chart ). However, commercial kitchens must adhere to the local health department standards for temperature safety controls. In the state of South Carolina that is DHEC (seen here — https://scdhec.gov/food-safety-proper-cooking-reheating-temperatures).
Temperature controls go beyond cooking and serving. Proper food temperature controls affect how food is properly refrigerated, stored and held for service in a commercial kitchen. Ultimately numbers matter when doing temperature controls because proper temperatures lower the risk of your clients being exposed to bacteria and food borne illness.
2. The power of the “oz”
Have you wondered how chefs prepare for large groups? Or have you ever wondered how restaurants don’t lose money when large groups cancel or drastically reduce the sizes of their parties. The answer lies in the power of the “oz.”
When I refer to the “oz” I am talking about the abbreviation for ounces. Ounces are such a nimble metric of measurement. Perhaps the crux of its versatility can be found in the fact that oz can either denote weight or volume (fl — fluid). Perhaps it’s because oz are listed as the unit of measure on many food packages. Perhaps it’s because it can easily be converted to the small measuring cups that are popular in many households. In either case I have observed that chefs will regularly rewrite all of their recipe ingredients in “oz.”
This simple measurement chart below demonstrates the power of having one consistent measuring standard.
Measurement Chart
3 teaspoons = 1 Tablespoon
1 Tablespoon = .5 oz (approximately)
2 Tablespoon = 1 oz
¼ Cup = 2 oz
1/2 Cup = 4 oz
1 cup = 8 oz
2 Cup = 16 oz = 1 Pint
1 Quart = 32 oz
.5 Gallon = 64 oz
.75 gallon = 96 oz
1 Gallon = 128 oz
Now we see that the chef’s vision is laser focused on the “oz.” How do we convert ingredients for a small party to a larger party and vice versa? Insert the conversion factor.
3. The Conversion Factor
The conversion factor is found by dividing the New Yield or the amount we are going for by the Old Yield then interacting with every ingredient in the recipe.
Brief aside, you may be asking what is a yield? There are two major ways the term yield is used in culinary. The first being the standard way it’s defined in the dictionary and the way that we will be defining it here in this section as the being amount produced or the desired amount produced. For the second way that yield is defined, I will elaborate in the next section of this article. In brief, that other type of yield is defined as the percentage of the whole food item that is actually edible after it’s been shucked, shelled and or the excess has been removed.
However, if we stick with the first definition of yield (as described in this post) we are talking about the amount that we desire to produce. When we are trying to convert a recipe from one yield to another we use the Conversion Factor Formula.
Conversion Factor Formula
New Yield divided by Old Yield = Conversion Factor or
NY / OY = CF
The best way to clearly explain all of the elements that I have described in this section is through illustrating it in a case study. So using a Strawberry Sorbet recipe that I found at King Arthur Baking.com (https://www.kingarthurbaking.com/recipes/strawberry-sorbet-recipe) hopefully it can help you process information more like a chef would.
The Strawberry Sorbet Case Study
Greeting Chef, about 6 months prior to an event you have tasked to prepare one cup of Strawberry Sorbet for 160 people. On the day prior to the event the number of guests grew from 160 to 240 people. You set out 240 cups of Strawberry Sorbet, the only problem is that only 56 people arrive. The goal of this case study is to 1. Convert the original recipe to “oz” and see it like a chef would see it. 2. Convert the recipe for 240 people 3. Reduce the recipe to what would have been needed if you knew you were only serving 56 people.
1 Cup of Strawberry Sorbet = 8 oz
Original Recipe Yields (in this case the first definition of produce applies) = 1 Quart or 32 oz of Sorbet
Original Recipe
1 Cup of Water
¾ cup of granulated sugar
1 pound of Strawberries
⅓ Cup of Lemon Juice
Chef Vision for Original Recipe (Remember the oz conversion)
8 oz of water
6 oz of granulated sugar
16 oz of Strawberries
2.67 oz of Lemon Juice (in this case 2.67oz would be rounded up to 3 oz)
Recipe prepared for 160 People
The original recipe yields 1–8 oz cup for 4 people.
160 divided by 4 equals 40. This means that the recipe needs to be multiplied by 40 times.
160/4 = 40
8 oz of water x 40 = 320 oz
6 oz of granulated sugar x 40 = 240 oz
16 oz of Strawberries x 40 = 640 oz
2.67 oz of Lemon Juice (in this case 2.67oz would be rounded up to 3 oz) x 40 = 120 oz
Recipe for 160 people converted to 240 People
New Yield / Old Yield
240 /160 = 1.5
The conversion factor of 1.5 means that each ingredient in the recipe for 160 should be multiplied by 1.5
320 oz of water x 1.5 = 480 oz
240 oz of granulated sugar x 1.5 = 360 oz
640 oz of Strawberries x 1.5 = 960 oz
120 oz of Lemon Juice x 1.5 = 180 oz
Recipe for 240 people converted to 56 People
New Yield / Old Yield
56 / 240 = .233
The conversion factor of .233 means that each ingredient in the recipe for 240 should be divided by .233
(The decimal point changes the multiplication to division)
480 oz of water x .233 = 111.84 oz or 112 oz
360 oz of granulated sugar x .233 = 83.88 oz or 84 oz
960 oz of Strawberries x .233 = 223.68 oz or 224 oz
180 oz of Lemon Juice x .233 = 41.94 oz or 42 oz
Remember LoneSoMe SaLaD
You probably noticed that when you converted the recipe from a larger amount to a smaller size you divided and when you converted the recipe from small to larger you multiplied. Chefs created a mnemonic device to remember this it’s “lonesome salad” or better spelled out “LoneSoMe SaLad”. The emphasis is on the capitalized letters L…S…M… in “lonesome” means if the recipe is being converted from Large to Small then you Multiply. The S…L…D in “salad” means if the recipe is being converted from Small to Large then you Divide. When converting recipes remember the “LoneSoMe SaLaD.”
4. Calculating Yield Percentage
The best way to describe yield percentage is to think of a lobster or shellfish. Let’s say hypothetically we purchase a 2 lb lobster in its shell. After cracking the shell and removing the lobster meat we discover that the lobster is 8 oz of lobster meat. The yield percentage is the percentage of the lobster that a person can actually consume or that is edible.
The formula for Yield Percentage is
Edible Portion divided by the As purchased amount multiplied by 100 = Yield Percentage
or EP / AP x 100 = YP
In the aforementioned case study of the lobster.
8 oz / 2 pounds (or 32 oz) x 100 = 25%
Using this formula “Market Price” for lobster is not determined by the 2 pounds of lobster in the shell but rather by the 8 oz (or half pound) that is edible.
This yield percentage is the basis of how a chef or restaurant should properly charge for its food if it wants to remain in business. In this situation a restaurant could literally charge double what it paid for this lobster and after selling every lobster it bought would still lose money if the yield percentage is not accurately accounted for.
Yield percentage is not just something that applies to shellfish it applies to every menu item in which the as purchased is different from the edible portion. The numbers for yield percentage matters because it appropriately calibrates your prices.
If a person is looking for an industry standard resources that calculates yield percentage check out the book The Book of Yields by Francis Lynch (seen here — https://www.amazon.com/Book-Yields-Accuracy-Costing-Purchasing-ebook/dp/B005FHM6V4)
5. Establishing your food prices based on food cost
One major expense for any restaurant or food service business is the cost for food. As aforementioned, the yield percentage must be taken into consideration when calculating prices. Another factor that a prudent food salesperson should think about is what my average food cost will be when setting prices.
The food cost is the total cost for the pre-prepared food per item sold that will be prepared and sold. I got an opportunity to interview four successful restaurateurs/chefs (that reasonably priced their food) while in school and they recommended setting your prices (percentages based on an average between the four) between 25 and 33 percent of your food cost. (also described within the industry as menu item cost percentage )
In brief, if a restaurant has set their prices at an average of thirty percent food cost then the $7 sandwich purchased by the customer cost the restaurant about $2.10 to make.
The food costs are not the only things that food entrepreneurs are to take into consideration; utilities, salaries, emergencies, marketing etc. However, within the food industry determining food prices based on menu item cost percentage is industry standard. While I will not elaborate during this post, the industry standard for calculating other expenses is done with assessing monthly break-even point analysis. The general thought is that the other expenses (in addition to food cost) will be reached through net profit gains.The Break Even point is also based largely on what a vendor sells because variable expenses have to be factored into the equation.
This is an example of monthly break even point taken from Culinary Math: Principles and Practices textbook
Break Even Point = Fixed Expenses / 100% — Variable Expenses Percentage (of net sales)
Now referring back to the menu cost percentage, the question must be asked: what is the process of finding out the food cost per item? In order to understand the food cost a restaurateur must break down the cost of each ingredient and add them together for the total cost of each food item on their menus.
6. Learning your recipe cost by assessing your ingredients
Last but not least, when we are determining the price for the food we must interact with the recipe cost.
Each recipe is made up of the sum total of its ingredients. It’s important to also remember that one completed recipe may create more than one menu item. This is the reason that it’s recommended to create our recipe cost form based on a completed recipe then divide the total recipe by each menu item.
Below I took the liberty of using the aforementioned Strawberry Sorbet recipe and adding into a standard recipe cost form as individualized package freeze pops. The goal of the spreadsheet below is assessing the price of Strawberry Sorbet Freeze pops if you were factoring each pop being sold at a price that exceeded thirty percent of the food cost. “Recipe cost forms’ can be found with a simple internet search and it’s recommended that they be worked out for each menu item on one’s menu.
Definitions -
Ingredients — Ingredient Names
Edible Portion Amount — The edible portion (EP) amount is the amount of each ingredient (after trimming) that is required to prepare the menu item.
As Purchased Unit Cost — The unit cost for each ingredient in the same unit of measure as the edible portion (EP) amount of each ingredient.
Yield Percentage — The yield percentage (YP) of each ingredient listed.
Edible-Portion Unit Cost — Calculated by dividing the as-purchased unit cost of each ingredient by the ingredient yield percentage (YP).
Total Ingredient Cost — The total cost for each ingredient is calculated by multiplying the edible-portion (EP) amount of each ingredient by the edible portion unit cost of each ingredient.
Target Price — Calculated by dividing the as-served cost per portion by the target cost percentage.
Menu Item Cost Percent % — The actual menu item cost percentage after the math is performed.
The recipe cost forms are very helpful for food entrepreneurs that are looking to determine reasonable prices that will also help them be sustainable as a business.
Conclusion
In conclusion, the numbers matter in the culinary industry. Numbers are how we determine if our cooked food is done via temperature. We simplify our numbers by changing our ingredients to ounces or “oz”. We use the conversion factor when we want to make our recipe size numbers larger or smaller. We use the yield percentage factor when we want to determine the number of our edible portions of food that need to be calculated into our food cost. The food cost numbers of 25% to 32% mattered greatly to the experienced chefs that I interviewed when determining pricing. Lastly, each ingredient number matters and needs to be calculated when factoring the menu item cost percentage.
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