Decadent Crème Brûlée
Well conducting this experiment, I tested how the use of different eggs affected the density of the Crème Brûlée, as well as the overall desirability. In particular, I was looking at the effects that heightened levels of yolk protein and saturated fats would have on the end texture and weight. The three eggs I tested came from James Ranch, a local farm that produces pasture-raised eggs rich in protein and virtually without saturated fats, organic eggs, a fair middle-ground where the eggs come from a CAFO (confined animal feeding operation) but are fed a slightly less synthetic diet, and non-organic GMO CAFO eggs, lower in proteins than the others, but with significantly higher saturated fat levels.
So what effect do saturated fats and proteins have on the texture of your Crème Brûlée? For fat to be saturated, it means that each carbon in the chain has two hydrogen atoms bonded to it, eliminating all carbon double-bonds and effectively straightening the molecule out. Unsaturated or polyunsaturated fats, on the other hand, contain one or more “gap” where two adjacent carbon atoms do not have two hydrogens, and so form a double bond. This gap means that the fat molecule develops a “kink” or bend, making it stack much more irregularly than saturated fats. This means that saturated fats stack more densely, and lead to more dense custards.
Protein, on the other hand, is the glue that sticks recipes like this together. When it is heated, a protein molecule (a long chain of carbons) unravels into a long string, which then can cross with other proteins and form a lattice adding rigidity and firmness to the pudding. This means that the more protein there is in a custard, the denser it will end up being.
The first test I conducted was a qualitative survey of several taste-test participants. When asked which of the custards was their favorite, the test subjects nearly unanimously picked the one with pasture-raised eggs as their favorite, quoting it’s more complex flavor as their chief reason. The second test was a qualitative comparison of the differing densities. This was the place where my hypothesis was the least certain, as protein and saturated fat both increase density. The results, however, showed that the increased protein content of the pasture-raised eggs more than compensated for the lack of saturated fats, making the densest pudding.
The hardest part of conducting this experiment was undoubtedly deciding which way my hypothesis should go. It would be easy for either the eggs with more saturated fats or with more proteins to make a thicker pudding. There was no research that I could find comparing the thickening properties of protein and saturated fats. Even when I looked into something as straight-forward as the protein contents of egg yolks in CAFO vs pasture-raised eggs, the research was murky at best, with several sources openly contradicting each other. In the end, after weeding out the most reliable sources, I decided to hypothesize that the increased protein in the pasture-raised eggs would out-weigh the increase in unsaturated and polyunsaturated fats, making the pasture-raised eggs producing a denser pudding.
The results of the experiment, while apparently conclusive, were far too shallow of an answer to the question I presented. I am left with more questions than I started with, such as what the actual amounts of proteins, saturated fats, and unsaturated fats were in the different yolks. Is the thickening power of protein even comparable to that of saturated fat? Can they be equated to each other, are their individual modus operandi too different for them to be talked about the same way? My questions have not gone away, they have simply evolved, but that’s science.
So what effect do saturated fats and proteins have on the texture of your Crème Brûlée? For fat to be saturated, it means that each carbon in the chain has two hydrogen atoms bonded to it, eliminating all carbon double-bonds and effectively straightening the molecule out. Unsaturated or polyunsaturated fats, on the other hand, contain one or more “gap” where two adjacent carbon atoms do not have two hydrogens, and so form a double bond. This gap means that the fat molecule develops a “kink” or bend, making it stack much more irregularly than saturated fats. This means that saturated fats stack more densely, and lead to more dense custards.
Protein, on the other hand, is the glue that sticks recipes like this together. When it is heated, a protein molecule (a long chain of carbons) unravels into a long string, which then can cross with other proteins and form a lattice adding rigidity and firmness to the pudding. This means that the more protein there is in a custard, the denser it will end up being.
The first test I conducted was a qualitative survey of several taste-test participants. When asked which of the custards was their favorite, the test subjects nearly unanimously picked the one with pasture-raised eggs as their favorite, quoting it’s more complex flavor as their chief reason. The second test was a qualitative comparison of the differing densities. This was the place where my hypothesis was the least certain, as protein and saturated fat both increase density. The results, however, showed that the increased protein content of the pasture-raised eggs more than compensated for the lack of saturated fats, making the densest pudding.
The hardest part of conducting this experiment was undoubtedly deciding which way my hypothesis should go. It would be easy for either the eggs with more saturated fats or with more proteins to make a thicker pudding. There was no research that I could find comparing the thickening properties of protein and saturated fats. Even when I looked into something as straight-forward as the protein contents of egg yolks in CAFO vs pasture-raised eggs, the research was murky at best, with several sources openly contradicting each other. In the end, after weeding out the most reliable sources, I decided to hypothesize that the increased protein in the pasture-raised eggs would out-weigh the increase in unsaturated and polyunsaturated fats, making the pasture-raised eggs producing a denser pudding.
The results of the experiment, while apparently conclusive, were far too shallow of an answer to the question I presented. I am left with more questions than I started with, such as what the actual amounts of proteins, saturated fats, and unsaturated fats were in the different yolks. Is the thickening power of protein even comparable to that of saturated fat? Can they be equated to each other, are their individual modus operandi too different for them to be talked about the same way? My questions have not gone away, they have simply evolved, but that’s science.