I am looking for a good, in-depth source on biotransformations (think food science). For example, fermenting black tea and sugar with wild yeast and bacteria (kombucha):
- Wild yeast ferment sucrose into ethanol
- Bacteria (in the presence of oxygen) convert that ethanol to acetic acid (sours the solution and lowers pH)
This is a transformation of sucrose into acetic acid through the use of yeast and bacteria (but which ones?). Or:
- Malting grain causes production of enzymes that later break down starch into sugar
- Mashing crushed grain allows starch extraction and conversion (by these enzymes) to (fermentable) sugars such as maltrose, dextrose, sucrose, etc.
I'm interested in what enzymes are produced by which grains, and how they convert starches and in what temperature ranges.
I want to study these types of biotransformations, including how varieties of yeast and bacteria make these transformations (i.e. bacteria converting ethanol to acetic acid only when oxygen is present). This means details on yeast, bacteria, and how they interact with one another in transformations of molecules (thus aromatic/flavor compounds, production of alcohol and acids, etc.).
Is there an authoritative (or close to it) source on the micro-level biotransformations that occur during fermentation? I only know what I know from reading online about brewing kombucha and beer; sources seem to just say "this happens when this", but without explanations as to what is doing what, which is what I want to know more about!
Super bonus points if there's a sort of almanac of common brewing ingredients. For example, breakdown of various malts and their enzyme content, adjuncts such as herbs/spices and their chemical makeup (e.g. linalool, citronellol, etc.), the like. I find the micro-level of fermentation fascinating, and I'd like to finally learn how to balance the bitterness of my hibiscus saison by taking advantage of microbes or a change in the preparation of ingredients/fermentation.
I just found an amazing example of the genre of information I'm looking for on Chemistry.SE. It talks about the use of lemon juice in cooking with fish, and the reason why so many recipes use lemon juice. There is a chemical reason for adding lemon juice, and it's fascinating to see those molecules interact to change a dish. I'd love to have this kind of information, but for beer.