CBC Online Seminar Q&A Basic Enzymology for Brewing

Q: Any applications or examples of using Koji for in brewing? A: Yes! I can’t speak too much about this since I haven’t personally, but Koji has a TON of , including , proteases, lipases, and tanninase. I do know that Wynkoop Brewing in Denver has a head brewer who is also an award-winning home Sake brewer. They created a hybrid beer using Koji, but they essentially had a second-mashing process in the fermenter. It created the driest beer I think I’ve ever tasted, it was great! - Q: Could you touch on how amyloglucosidase works and how it’s used in the brewing process? A: I go into this in depth in the seminar Practical Enzymatic Brewing, also from this year’s online CBC. It functions essentially the same way β-amylase does, from the ends of the starches, but creates instead of maltose. It can be used to breakdown all the fermentables into glucose, or used in the fermenter towards the end of fermentation to dry the beer out more. The concern is that, if used in the mash with endogenous enzymes, it can raise the glucose levels to a point that the yeast won’t eat the maltose (‘glucose-suppression’). Please watch the Practical Enzymatic Brewing seminar for more info! - Q: What is it about pH that affects performance? A: The pH changes the ratio of positive or negative ions in the solution. The structure of proteins (and thus enzymes) is held together by internal bonds of ions, and as the external solution changes charge it can interfere with these internal bonds, distorting or destroying the overall shape of the enzyme. This prevents the substrate from being able to ‘lock’ into the enzyme. - Q: What is the difference between gelatinization and solubilization? Is gelatinization a form of solubilization? A: Gelatinization is the swelling of starch granules, solubilization is the entering into solution of a substance (not necessarily starch). There is some confusion in the brewing world about these terms, in large part because they are processes of great importance to distillers but rarely considered by brewers. Gelatinization is the swelling and loosening up of the starch granules to expose the starches to the overall solution – liquefaction is the next step in the process, where those starch granules are then broken down to the point that they can easily enter the solution (primarily by α-amylase and limit- / pullulanase – this is represented by a drop in wort viscosity). This overall process is the solubilization of the starch. The gelatinization must occur first in order for the liquefaction to occur. Here is a great graphic from https://craftdistilleredu.wordpress.com/2014/11/14/starch-liquefaction/ -

Other biochemicals also get solubilized, like the materials of the cell wall, without gelatinization. - Q: Diastatic power varies from grain to grain (and between malt types). Does the proportion of endogenous beta amylase (to alpha) vary between different grains? A: In short, yes, but I don’t have a great single chart outlining the differences. But, for example, the diastatic power of barley malt is typically in the mid 40’s DU, while millet malt is in the mid 20’s DU. - Q: Do you have any information about the enzyme process of malting corn? A: I do not have the process nearly to the same degree of what I laid out here for barley, but the process of malting a grain is fairly similar so long as it has an embryo and endosperm. A quick look at the recommended process for malting corn shows me a parallel to that of barley, so I’d assume the internal processes are similar was well, but this is outside my area of expertise. - Q: Are there enzyme inhibitors found in malt besides ? A: Oh, I’m sure. There are thousands of enzymes in malt, but of the dozen or so that are critical for brewing, limit dextrinase is the only one with an inhibitor of note. - Q: Can you please talk about optimization of enzyme activation in quinoa? A: Please watch my second presentation, Practical Enzymatic Brewing, as I think it will address some of your question. However, as I spent 3 hours in total talking about barley optimization, this question is worthy of its own presentation! - Q: Enzyme cocktails address different mashing challenges to decrease run-off time, increase extract, reduce wort viscosity, etc. Is such a mix useful when well-modified malt and no adjuncts are used? A: It absolutely can be, depending on your goals! Please watch my second presentation, Practical Enzymatic Brewing, as I go through a number of different reasons why exogenous enzymes may be used. One common use is to reduce variability in malt form batch to batch, and another would be the creation of specialty products (like low-cal / low-carb / Bruts). - Q: Is there any information on enzymes contained in the grain that could perform the union between sugar and hop terpenes during mash hopping? A: The enzyme you are referring to is β-glucosidase, which is also present in yeast. This is the main benefit of mid-fermentation hopping, like is commonly done on hazy IPA’s, and creates a number of different aromatics (and some more fermentables) than traditional post- fermentation dryhopping. I personally haven’t done mash-hopping, because any aromatics that arise would be boiled off! I personally don’t see a benefit here, though I know this is an emergent idea. - Q: Can we get a bibliography for the topics today? A: Please check back on this site, they should be up in the next few weeks. If you are reading this In ThE FuTuRe, it’s probably already here! - Q: Is there any momentum that you're aware of to describe the potential enzymatic power in various hop strains that could inform hop creep risk? A: Not that I’m aware of. For more information on hop creep, check out the presentation from Oregon State on this year’s CBC!