cookie tech 102

While I was playing around with a corn base and hydrocolloid synergies, Fabian came in with some cookies and an interesting discovery...

These 3 cookies were all made with the same recipe.  The only variation was in how the baking soda was introduced into the mix.

The cookie on the left (the really flat one) had the baking soda mixed in dry with the flour as in most traditional cookie recipes.

The cookie in the middle (good but not best) had the baking soda mixed with cold water before introducing it into the recipe (the ratio was 1 tsp water for every 1/2 tsp soda).

The cookie on the right (the fluffiest and fullest) had the baking soda mixed with very hot tap water first (at the same ratio of 1 tsp water to 1/2 tsp baking powder).

Although the 2 on the right have water added (which truly introduces a new variable), the difference in how the baking powder is treated creates amazingly different results (nicer browning as well as more rise).  The next obvious thought was the how and why?  Although we are not qualified to answer that, it seems that the baking soda (as do hydrocolloids) benefits greatly from being dissolved or hydrated (as in the case of the hot water) before being introduced to the other ingredients.  Possibly, the swollen starch encapsulates some of the baking soda and inhibits a lot of it's power.  This makes sense considering a dry mix of flour and baking soda will be introduced to water at the same time, and the flour starches may easily begin to hydrate or swell before the baking soda and prevent it from hydrating fully.  Also consider that most cookie recipes insist on not overmixing, so the leavening agent is never fully incorporated into the mix.

This is probably common knowledge to an entire slew of pastry chefs out there, but to Chef K and I it was something new... and learning something new everyday is a good thing (and neither of us recalls ever reading this in any cookie book).  It had us thinking about other applications of baking soda (such as frying batters) that may benefit as well from this knowledge.

Thanks, Fabian.  If not for these cookies, I would have just had a bunch of pictures of corn pudding to post.  This is much more interesting.

Comments

[Harlan]

Interesting. Did the baking soda dissolve in the cold water? How acidic is your water? Your suggestion about the poor incorporation of the baking soda seems like it might be part of the key. For baking soda to work, it has to react with an acid. (Interestingly, there are no explicit acids in cookies, aside from maybe the chocolate chips.)

Also, did you control the time well in this experiment? Baking soda is not triggered by heat, like baking powder is, but by the acid, so if you let the dough sit longer in the first batch before baking, it could have inflated then deflated some.

[Roberto N.]

I remember a recipe for cupcakes that called for 1 tsp of Baking soda dissolved into 1 tsp of vinegar. One was supposed to do that just before adding, and letting the fizz die before doing so. I could try that with cookies and see what comes out...

[Graeme]

I have very limited knowledge on the subject, but I wonder if the browning & rising is similar to that in a baguette. The longer the outside stays moist (higher hydration), the more time it has to rise before becoming "a prisoner of it's own crust" as James Macguire would say.

I wonder what an autolyse would do for chocolate cookies. Hmmmmm...you've got me thinking. Thank you...

[Martin Lersch]

Very interesting observations!

Perhaps you could post the recipe? As Harlan points out baking soda is triggered by reaction with acids. I'm just wondering if any of the ingredients could be slightly acidic.

When you mixed the baking soda with the cold water, did it dissolve? I assume it dissolved when using hot water.

[simon]

This recipe calls for exactly that method:

http://allrecipes.com/Recipe/Best-Chocolate-Chip-Cookies/Detail.aspx