A woman came into the shop a couple of weeks ago, having heard that since we're nut-free and Chef Alex has a nut allergy herself that we understand about allergies and because, well, we're the sort of folks to just help people out. (Such a nice reputation to have!)
The woman's two children don't have allergies but rather a rare genetic disease called "PKU" or
Phenylketonuria. In short, these children will have to follow a virtually protein-free diet for the rest of their lives or extremely (and I do mean extremely) serious health conditions will occur. They can't have flour, eggs or milk (although butter and heavy cream are ok as they don't have the amino acid "phe"). Gluten-free flours may be acceptable. Our gluten-free flour mix was ok, but our recipe needed eggs to work properly.
Did I mention these kids have never had a birthday cake? Mom had tried making them according to websites that offer PKU recipes and said they had been a disaster. "Disaster" she says. How hard can it be with a mix, we thought? Um.....ya, ok - read on.
The mom gave us three things to try as flour substitutes. One was a "baking mix", another a box of wheat starch with other ingredients and finally a box of pure wheat starch. We went to the baking mix website and found a cupcake recipe, although there was no recipe for cake, which was weird because they should be the same thing. So we used the mix and noticed the batter was really stringy and starchy, but we baked them off anyway. They came out like this:
Ok, so ... what if we used this "flour" in our own vanilla (vegan) cake recipe? No dairy or eggs, so it should work, right? Check it out:
Brilliant insight: we're trying to make this cake lemon, so perhaps the acid is the problem. He'll have to settle for a vanilla cake. This one?
Maybe if we cooled it. Put more batter in the cup this time. So at 11pm we tried that and as a result Alex started playing softball again :
By this time it was frickin hilarious. We laughed so hard we cried.
Then we really cried, because we were hell bent for leather that this kid was going to get a birthday cake. So at midnight we put our thinking caps on. Our gluten-free cake recipe has less than 1g of protein per serving. So the only problem with it was the 3 eggs the recipe calls for. How can we replicate an egg? (Yes, we know there are egg substitutes, but we're an all-natural bakery so that was out. Plus it was midnight.) Eggs serve a number of functions in a recipe such as emulsion (binding it all together - particularly if there's no gluten), fat content, water content, and leavening. So we set out to make eggs with the ingredients we had on hand. For emulsion, we used 1/4 cup of the wheat starch (it was gloppy and stringy, so why not?) For fat, we used 3/4 cup of butter since butter is ok for PKU diets. We added water for water, and some extra baking powder for leavening. We also decided to try to make it lemon again. The cupcakes rose up beautifully, and then this happened:
Back to the drawing board - what makes a cake rise, then fall? Too much leavening for the strength of the flour to uphold. Overbeating big bubbles of air into the mix, perhaps. Rising too quickly, perhaps. We'd have to address all three variables at once before we turned back into pumpkins. Wait. We were already pumpkins. So we went home to bed. The next morning we cut back on the extra leavening, mixed carefully, turned down the oven. Went for it by adding the lemon.....and, voila!
And people ask us what a "spiritual ingredient" is. Well there you have it.