My personal experience has been the use of procedures and techniques that maintain an appropriate level of sterility of all items used in the beer making. Whether this is part of the process (boiling) or a separate cleaning procedure (bottle washing, filling, capping) it allows the yeast time to reach critical mass. This stops any bacteria or fungi that survive the process from getting a foothold and taking over the fermentation process.
I think the biggest thing I get out of my chemistry background in brewing is an understanding of water chemistry, which really help in keeping the pH in the target range for all-grain batches.
Ditto. Sanitation procedures and water chemistry are both important. I've noted that, where I used to live at least (Missoula, Montana, between the Bitterroot and Rocky Mts with their calcareous formations), water chemistry can vary slightly over the course of the year, depending on the source, snow melt, etc, and I used to have to check the water periodically and adjust accordingly (depending on the beer I was brewing).
The last beer I made used primarily pilsner as the base malt, with 10% wheat malt, but I had added enough darker malt to necessitate the addition of a small bit of CaCO3 to the mash to keep the pH in the desired range. The dark malts lower the mash pH. Conversely, when I brewed a tripel style ale some time ago I added some distilled water to the filtered LA county tap I use to "soften" it a bit, since I used only pilsner and a little wheat malt (with a homemade invert syrup from turbinado sugar).
Definitely agree with sanitation. I think my chemistry training made me obsessive about clean glassware, which helps keep everything nice and sanitary. This is probably the most important factor in successful homebrewing.
I have to agree with all the current posts that sanitation, general laboratory practices, and using the scientific method have, in general, helped me in many stages of brewing. One overarching area in which I think being an experimental scientist has been a great boon is the "go ahead and try it" attitude. I have made several different (but very good) batches of beer through experimentation! I am also particularly interested in water chemistry and how it affects different parts of the process and one's success in duplicating certain styles -- water chemistry is an area in which I hope to learn much more.
One thing I have found very interesting is the utilization of hops -- what a complex process! When added at the beginning of the boil, aroma compounds boil off, while certain compounds remain in solution, isomerize, and become responsible for the bitter flavor. When added at the middle of the boil, compounds of intermediate extraction efficiency and volatility are extracted, resulting in hop flavor. Finally, those added at the end of the boil result in the enticing hop aroma emanating from your foamy pint! I wonder about the extraction processes at work when when performs dry-hopping or when one runs beer through one of these in-line "hop filters" during the dispensing process. Ultimately, I hope to get a hop-back for yet another hop-addition option.
Anyone have any experience in a lab performing extraction/separation of hop components?
As for extracting hop components, I've only done some UV analysis of hop bitterness in beer, using a method from the ASBC Methods of Analysis. I have a couple of HPLC and GC methods for the separation and determination of alpha and beta acids and other compounds, but have never gotten around to playing around with them. The HPLC methods (ASBC and EBC) use essentially the same extraction and chromatographic conditions (a two phase ether and methanol extraction system and mobile phase of MeOH, water, and phosphoric acid under isocratic conditions).
I'd be happy to send some literature or provide references if anyone is interested.
Here are a couple of links to hop-related discussions (not analytical methods per se, although the first does include an EBC UV-vis spectrophotometry method for determining hop bitterness units), the first on hop utilization and the second on an old, revived German technique known as First Wort Hopping that might be of some interest:
I've never tried the FWH technique but plan to test it out on a pale ale sometime next spring. Sounds intriguing.
I actually had a friend who did a batch of a "Pliny the Elder" clone in which he employed the FWH technique. Never knew the background, though...
I have actually done some HPLC analysis of hops using the ASBC methods and it is pretty neat. I did testing on some of my advisors homegrown hops and some wild hops we found. What was intersting to see is that the wild hops had a much higher concentration of the beta acids while the commercial hops are mostly alpha acids. If you get a chance you should play around with the method.