How An Arizona Baker Used Statistics to Make the Perfect Croissant

Is there a better treat for breakfast or tea than a freshly baked croissant? Pure light, flaky, buttery goodness that transports you, in imagination at least, to Paris.*

But you know that making croissants de boulanger is going to be complicated when you see that the recipe (Mastering the Art of French Cooking, Volume 2, by Julia Child and Simone Beck) spans eight pages. Child and Beck list a minimum preparation time of 11 hours and state that “if you want freshly baked croissants for breakfast you will have to stay up all night as the bakers do.”

You first have to make the dough, adding just enough flour so that the dough will hold together but you don’t over-activate the gluten. Then let it rise three hours, deflate, and let it rise again. Then beat a stick of butter with a rolling pin (Julia Child seemed to really enjoy that part when she made croissants on her television show) and spread it over the top two-thirds of the rolled-out rectangle of dough. Fold the rectangle in thirds; roll it out and fold it again. Now rest the gluten another hour and a half. Roll it out and fold into thirds twice more. Each time you fold, you triple the number of layers of butter, so at the end of the folding you have 2 x 3 x 3 x 3 = 54 layers of butter separating 55 layers of dough. But all this rolling and folding has stressed the gluten, so the recipe says to let the dough rest again before rolling it out one final time, cutting triangles, coiling the triangles into crescent shapes, and baking. Result after following the Child/Beck recipe: 12 croissants and a home baker who is too exhausted to enjoy them.

That’s why I was so delighted to discover the croissants at Early Baker, a family-owned restaurant and bakery near the intersection of 40th Street and Chandler Boulevard in Phoenix, Arizona. They’re freshly baked every day and are everything croissants should be — flaky on the outside, soft with lots of layers and pockets of air on the inside, and suffused with delicate buttery flavor.

I chatted with Adam and Kinana, the restaurant’s owners, about how they make such yummy pastries. It turns out Early Baker’s secret for heavenly croissants is … using statistical methods!

Before becoming a restaurateur, Adam worked as a semiconductor engineer, where he had used statistical design of experiments to improve processes for making computer chips. Kinana studied baking while the family lived in Japan (although she has a degree in medicine, she did not have the visa to work as a physician there). Japanese cheesecake, a fluffy and jiggly confection that resembles a hybrid of pound cake and American-style cheesecake, is another of her specialties.

The beauty of statistical methods is that they apply to any discipline. The same types of designed experiments that provide information on how to improve computer chips or evaluate cancer treatments can be used to make better coffee and develop transcendent croissants.

Croissant-making has a lot of steps, and each can affect the taste and texture of the final product. What if you shorten or lengthen the rest periods, or use a different number of layers of butter? Do you need to change the proofing time if you double or triple the recipe? What type of flour and butter should you use? Moreover, changing one aspect of the recipe can affect the optimal settings for other aspects, so one needs to explore how all of the factors interact.

Adam and Kinana performed more than 20 experiments to perfect their recipe. The factors they studied included type and amount of flour, amount of water, butter type, butter temperature, how to distribute the butter on the dough, number of layers of butter, and proofing time and temperature. Each experiment brought them closer to their goal and suggested further refinements.

How did they compare the croissants from the different experimental runs? One measure, of course, is taste, but croissant quality can also be measured objectively by cutting the croissant in half and examining the spacing between the layers. An excellent croissant has good lift and even separation between the layers.

Adam and Kinana found statistical methods to be an essential layer for creating scrumptious croissants. Kinana is now experimenting with methods for making bagels. The early results indicate that these will be another mouth-watering triumph.

Footnotes

*The name is French, but food historians say that crescent-shaped pastries originated in Vienna. The Viennese kipfel, however, was not made with puff pastry, which was introduced later by bakers in Paris.