One of the biggest challenges most home cider makers face is finding apples that will provide sufficient phenolic compounds. The answer to the problem is often literally staring us in the face. It is the apple peel. “Apple Phenolics” is my attempt to guide home cider makers on how much peel to include. The baseline will be a single variety cider made from Harrison apples, which is historically supposed to be one of America’s finest cider apples. The Harrison has 122.4 ug/g of total phenolic compounds in the flesh(1). I’m assuming a 50% yield on the flesh to juice weight or 61.2 micrograms of phenolics per gram of juice, which may be too high. That is 0.0612 grams of phenolics per liter of juice. Yes, not all phenolics are the same and some are lost during processing but this is the baseline I used. In this review, I am looking at Arkansas Black apples. I use the peels from Arkansas Black in many of my ciders. Even ciders that don’t include Arkansas Black juice. The color of these is the main reason but they also have an amazing aroma. So, how many grams of Arkansas Black peels would be needed to generate the same level of phenolics as a Harrison cider?
Let’s follow the same above logic I have been using with 50% extraction of the phenolics from the flesh. Arkansas Black juice will give us 0.0112 g/l so we need an additional 0.050 g/l of phenolic compounds. The peels of the Arkansas Black contain 361.6 micrograms of phenolics per gram of peel and I am assuming we extract 100% of these. Therefore, each gram of peel will add 0.0003616 grams of phenolics. That means I need 138.3 grams of Arkansas Black peels per liter of juice (0.050/ 0.0003616) to give my cider the same amount of phenolic compounds as a single variety Harrison cider.
The 138.3 grams per liter (525 grams per gallon) is more than the 75-125 grams per gallon that I have been adding. On the other hand, its not a 100 times the amount either. Look at the phenolics in Arkansas Black versus GoldRush. The GoldRush peels are higher in everything but phloretin derivatives, which is what most of the Arkansas Black peel phenolics are. Does this make it better or worse for use in adding phenolics. As always, the answer is probably that it depends. I get great color and aromas when I use Arkansas Black peels and some astringecy but not much bitterness. This takes us back to the question of what phenolic compounds should we be trying to add. Maybe it is phoretin based compounds or maybe it should be chlorogenic acids. When I look at the convergence of art and science in hard cider making, they seem to center around yeast and phenolics. Both are areas that we are just starting to understand and both are areas where I find the most resistance to change. Why aren’t move people using peels to make cider? Why don’t we have more non-Saccharomyces yeast available commercially? I hope you will join me in exploring these types of questions and you will share what you find.
(1) K.A. Thompson-Witrick and associates, Characterization of the Polyphenol Composition of 20 Cultivars of Cider, Processing, and Dessert Apples Grown in Virginia, J. Agric. Food Chem. 62, 2014
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