Friday, July 17, 2009

Friday Foto: Chocolate Cake

If you've ever experimented with gluten-free baking, you know that the process has some inherent challenges - How do you achieve a moist, chewy texture, rather than the dry, crumbly texture common to many GF baked goods? How do you stop the center of cakes from falling, creating concave craters once they're removed from the oven?

For nearly the last two years, we've succeeded in answering those questions by using our own custom flour blend (brown rice flour, sorghum flour, cornstarch, tapioca starch, and xanthan gum). But in very recent months, subtle changes took place, and after some sleuthing, we discovered tapioca starch/flour to be the culprit.

Variability among tapioca starches (and in particular, how finely ground the starch/flour is) resulted in a flour blend that had a stronger or weaker tapioca flavor in its profile, and a flour that absorbed moisture more or less readily, which affected both the yield of our recipes as well as the texture of the final baked good.

So, we went back into the kitchen, searching for a way to circumvent this tapioca dilemna. The naked chocolate cake above (unfrosted) is the result of one our experiments, which we've deemed a great success! And lo and behold, the solution proved to be eliminating the tapioca altogether, replacing it with a combination of potato flour and potato starch. (Note that tapioca flour and tapioca starch are synonymous, but that potato flour and potato starch are different... confusing, isn't it?)

The cake is moist and chewy without crossing the threshold into the realm of spongy, and it holds it shape and form very well. Hallelujah! (Of course, if you're making a flourless chocolate cake, all of this becomes a moot point, but that's another kind of cake entirely.) We like pairing this cake with a vanilla frosting, though it'd be easy to imagine lots of other options.

Have a great weekend!
- Pete


Anonymous said...

Beautiful cake! My cakes and muffins always collapse in the middle. It would have never occured to me that it could be the tapioca starch. I have a huge bag of potato flour in the freezer so I'll have to start experimenting. I just need to find some taste testers....

Did you enjoy Eagle? My parents moved there a few years ago and it's a great place to visit. Congratulations on the race!


peterbronski said...

Hi Janine... in our experience, GF cakes and such collapsing in the middle is a matter of finding the right flour blend balance, AND incorporating the right amount of xanthan gum to emulate gluten. We have successfully baked with tapioca starch in the past, so the collapsing I think isn't associated with it specifically.

Yes, we love Eagle! Aside from going there to visit friends, we've caved a Fulford, backcountry skied in the national forest, and had lots of other fun adventures. It's a great town and a beautiful valley.

Cheers, Pete

gfe--gluten free easily said...

Beautiful cake! I don't use tapioca starch. It bothers me, so I like your new substitution. I'm glad you found your answer. Sometimes it's a tough thing to do when having gluten issues (of any kind).


peterbronski said...

Hey Shirley... Kelli's glad to see the tapioca go, too. I've never minded it, but she's often been able to taste it in a recipe. We're super pleased with the new blend sans tapioca.

Cheers, Pete