After just finishing my post about How to Improve Your Cooking, my wife asked me Can we make cookies for X’s wedding? Oy. X is a close friend of ours and she’s gluten free. And not any of the bakeries in the St Louis bakery are able to produce Gluten Free cookies either in bulk or apparently at all. This calls for my standard gluten free cookie recipe but the volume calls for a re-examination and planning. And, in typical nerdy fashion, we must start with some math and a benchmark. And, yes, this is actually how an engineer approaches cooking at least when it matters.

Since my wife and son will be doing the actual baking, I’m documenting the full process since its an interesting application of math to domestic science.

Part 1: The Double Chocolate Cookies

Step 1: Math

Note: The addition of a second cookie type was a late change based on a successful cooking experiment with a new recipe. Oy. Let’s increase the complexity!

My wife estimates we need to make 250 cookies, 125 double chocolate and 125 peanut butter. This calls for a Google sheet to work up some numbers:

https://docs.google.com/spreadsheets/d/16IW5moFWTUneeNsLTIMt-c6uhXCAtQXOxy0p9yPSt0A/pubhtml

Note: There’s some kind of subtle spreadsheet error since I ended up with too many chocolate chips at the end; I think I didn’t allow for the right number of chips per batch or something.

This tells us that we need to bake for 1.5 hours w/ one sheet per oven (we have 2 ovens). A quick optimization is to bake two sheets per oven. This will give a slight increase in batch time from 12 minutes to 15 minutes but dramatically increase our thru put.

Step 2: Benchmark

A benchmark is the standard way we need to get our metrics. And the metric we need here is “How many cookies does a batch of batter make?” This is going to require a standard method of sizing each cookie which means we need a cookie scoop.

Once we have a cookie scoop then the next step is to bake a batch of cookies and figure out how many cookies a single batch of batter makes. From that we can then figure out how many batches of cookie batter are needed.

Step 3: Rewrite the Recipe for Weight not Volume

Something most american cooks are not aware of is that measuring dry ingredients by volume instead of weight is an american thing and it dates back to the westward expansion. What happened was an enterprising cook book author took the perspective that scales were heavy and fragile so why not rewrite all her recipes using just a volume measure. And that one thing changed the face of american baking. Now from a technical perspective the measure of dry ingredients can vary as much as 25% depending on how you fill the measuring up and that clearly can affect the result. Here’s a rewrite of our cookie recipe into a weight based approach:

Weight based recipes are generally easier to execute because you can sit a mixing bowl on a scale and then tare the scale back to zero after you add each ingredient.

  • 3/4 cups gluten free flour, Bobs Red Mill ==> 4.25 oz
  • 3/4 cups buck wheat flour ==> 4 oz
  • 2/3 cups coca powder ==> 2.5 oz
  • 1/2 tsp baking soda
  • 1/2 tsp salt
  • 1 cup butter flavored baking crisco (i.e. 1 stick); this is 2 sticks of actual butter
  • 2/3 cups sugar ==> 5 oz
  • 2/3 cups brown sugar ==> 5.75 oz
  • 2 eggs
  • 4 T rice milk or soy milk (dairy milk can be used) ==> 2 oz milk
  • 1 T vanilla ==> 0.5 oz
  • 1 bag semi sweet chocolate chips w/o milk

So here’s the full rewrite:

  1. Preheat both ovens to 350 and line four baking sheets with parchment paper.
  2. In a mixing bowl combine:
  • 4.25 oz Bob’s red mill gluten free flour
  • 4 oz buck wheat flour
  • 2.5 oz cocoa powder
  • 1/2 tsp salt
  • 1/2 tsp baking soda
  1. In the bowl for the standing mixer add the below ingredients and beat until fluffy:
  • 2 sticks butter
  • 5 oz brown sugar
  • 5.75 oz brown sugar
  • 2 eggs
  1. Add the below ingredients and mix:
  • 2 oz milk
  • 0.5 oz vanilla
  1. Add 1 bag chips and beat until combined.

  2. Use cookie scoop to place on cookie sheet and bake for 14 to 15 minutes rotating the sheets once at the 7 minute mark.

Step 4: Efficient Execution

Making 125 of anything means that you want to do it efficiently. The real constraints here are the fixed machinery of a kitchen specifically:

  • KitchenAid Stand Mixer (we have 1)
  • Ovens (we have 2)

To optimize the overall process, we can get a second mixing bowl for the stand mixer allowing two batches of cookie dough to be prepared at the same time. We can also add additional identical cookie sheets to make sure that the baking process is as uniform as possible. The efficiency gains from a second mixing bowl and additional cookie sheets far out weigh their relatively minimal cost.

Part 2: The Peanut Butter Cookies

Steps 1, 2, 4

Given the detailed write up above, we don’t need to do this again. The only real difference here is adapting the cookie recipe from volume to weight.

Step 3: Rewrite the Recipe for Weight not Volume

  • 1 cup smooth peanut butter => 9 oz (thanks Google)
  • 1/2 cup light brown sugar => 3.5 oz
  • 1/2 cup white sugar => 3.5 oz
  • 1 large egg
  • 1 tsp baking soda
  • 1 tsp vanilla
  • 1/4 tsp kosher salt

So a rewritten version give us:

  1. Preheat both ovens to 350 and line four baking sheets with parchment paper.
  2. In a mixing bowl combine:
  • 9 oz peanut butter
  • 3.5 oz brown sugar
  • 3.5 oz white sugar
  1. Add below and beat until combined
  • egg
  • baking soda
  • vanilla
  • salt
  1. Use cookie scoop to place on cookie sheet and flatten with tines of fork and bake for 10 minutes rotating the sheets once at the 5 minute mark.

Postscript

Well I’ve achieved success:

cookies_and_more_cookies.jpg

One thing to know is that gluten free cookies come out softer than normal cookies. This means they need to air dry for quite a long time to get hard enough to travel. The double chocolate chip cookies usually need 24 to 36 hours of sitting out before they are crisp enough. The peanut butter cookies can generally make do with 8 to 12 hours of air drying time.

The only downside to my success was that during the execution I figured out how to make them more efficiently still. Rewritten below are both recipes.

Double Chocolate Chip Cookies

  • Preheat both ovens to 350 and line four baking sheets with parchment paper.
  • In a four cup measuring cup combine:

    • 4.25 oz Bob’s red mill gluten free flour
    • 4 oz buck wheat flour
    • 2.5 oz cocoa powder
    • 1/2 tsp salt
    • 1/2 tsp baking soda
  • In the bowl for the standing mixer add the below ingredients and beat until fluffy:

  • 2 sticks butter
  • 5 oz white sugar
  • 5.75 oz brown sugar
  • 2 eggs

  • Add the below ingredients and mix:

  • 2 oz milk
  • 0.5 oz vanilla

  • Add 1 bag chips and beat until combined.

  • Use cookie scoop to place on cookie sheet and bake for 14 to 15 minutes rotating the sheets once at the 7 minute mark.

Peanut Butter Cookies

Note: This is effectively a double batch made in a single mixing bowl for volume. It will make at least 24 cookies (4 trays).

  • Preheat both ovens to 350 and line four baking sheets with parchment paper.
  • In a stand mixer combine:

    • 18 oz peanut butter
    • 7 oz brown sugar
    • 7 oz white sugar
    • 2 eggs
    • 2 tsp baking soda
    • 2 tsp vanilla
    • 1/2 tsp salt
  • Use cookie scoop to place on cookie sheet and flatten with tines of fork (both ways; you’re making a grid). Put in oven.
  • Set a 10 minute timer for the whole batch and a 5 minute timer so they can be rotated between top and bottom racks of the oven
  • Cool for at least 8 hours before you package for transport or try to put away.