When Things Go Wrong and Sister Bakers Collaborate Over the years, occasionally people have written to me telling me that their génoise comes out with a coarse texture and twice this has happened to me as well. It happened most recently when Woody and I were testing a 12 inch layer for an upcoming wedding cake. The recipe had already been perfected 26 years ago in The Cake Bible, but I was curious to see if it would work with Wondra flour which I subsequently found to be easier to integrate into the batter and to result in a more tender génoise in a 9 inch layer. I also wanted to see what the flavor would be like with rose water syrup instead of a liqueur. The batter filled the pan even more than usual and seemed to have more body but, to my dismay (actually horror), after about 10 minutes in the oven it started to collapse. On cooling and syruping, the resulting crumb was more toward cornbread than the usual fine texture.
My first thought was: "what would I say to a blogger who posted a question along the lines of: it always worked before so what went wrong? I would say: What did you do differently? And the answer was two things: I used a mixer with a different high speed from the Kitchen Aid on I usually use, and I replaced the cake flour/cornstarch mixture with the Wondra flour. The change of mixer explained the difference in volume and why the cake collapsed. So Woody and I went on to make a second cake using the usual highest speed on the Kitchen Aid mixer. The cake did not collapse, but the texture was still coarse and the cake tasted unpleasantly eggy. More often than not, when the texture is off the flavor is also affected but eggy? The first matter to deal with was the texture. We made a third 12 inch cake using the usual cake flour/cornstarch combination at the correct mixing speed and the cake again did not collapse, but the texture was still coarse and the flavor eggy.
I decided to reach out to my dearest friend and colleague, Lisa Yockelson. And sure enough, Lisa has been working on a recipe based on her own continuing research, which is why she understood my textural concerns immediately. Lisa asked if the cornstarch was genetically-modified, as we were going over the ingredient list, only to isolate every detail. The answer was yes, so we considered the possibility that it might be part of the problem. We had a long probing discussion at the end of which was a major part of the solution: Based on several years worth of research, Lisa has been adding an extra yolk to her 4 egg génois and using cake flour entirely. All cake flour made the biggest improvement, for it tenderizes the texture, adds delicacy to the finished "crumb," and refines the mouth-feel of the baked cake. In the end, in addition to a few other tweaks-in-the-works, Lisa has been using an extra egg yolk in a 4-egg génoise and 1 cup cake flour (sifted before measuring).
Coincidentally, I had mentioned to Woody at the start of making the first test génoise that since the proportion of egg yolks to whites is smaller than it had been in the past I wondered if this was going to have an effect on this cake. (Egg yolks have gotten smaller because the laying hens are now younger.) We have found, when making cakes where the yolks and whites are separated, or where all yolks are used, to get the equivalent of what used to be 4 yolks, you may need to use as many as 6.
Egg yolk provides natural lecithin which is a great emulsifier.. So I made yet another 12 inch génoise, but this time separating the 7 eggs and weighing the yolks and whites before combining them. I had to use a total of 9 yolks. I also replaced the cornstarch with equal weight cake flour Eureka: perfect texture. But once again I syruped the cake with the rose water syrup and it still tasted eggy. Back to the drawing board for the flavor solution. I made a 4 egg, 9 inch by 2 inch génoise, and syruped it with the usual syrup containing 2 tablespoons of liqueur. The liqueur was barely discernable but neither was the eggy taste of the cake. In future I may add more liqueur to the syrup (and reduce the water proportionately). I reported this to Lisa who loved the idea! I also decided not to point a finger at cornstarch unless I was certain it was part of the problem. So I made what I thought to be the final test (#6) with a 9 inch cake, using the correct amount of yolk but also the cake flour/cornstarch mixture. The results: acceptable but not as fine as using all cake flour. The right amount of yolk was the answer but not the whole answer. Just to seal the deal, Woody decided that one more test was necessary: test #7 was for a 9 inch cake, using the correct amount of yolk with the cake flour/cornstarch mixture using non-GMO Rumford cornstarch. And that was the winner. Compared to the 100% cake flour génoise, it was 3/16 inch higher but what was more important is that the crumb was finer, more even, and softer. Moral of the story: Either weigh or measure the yolks and whites separately, or add one 1 yolk for every 4 eggs. Use non-GMO cornstarch or replace the cornstarch with equal weight cake flour (for 3/4 ounces/100 grams, 1 cup sifted into the cup and leveled off). Add a minimum of 2 tablespoons of liqueur for a total of 3/4 cup/177ml syrup for the best flavor. 1/4 cup of liqueur will not be overpowering because a sponge-type cake does not hold the volatile liquid as effectively as a denser cake. Note: I have found that eggs graded jumbo now have yolks that are the same size as eggs graded large used to be so I often choose them and freeze the extra egg white for another use.