Discoveries from the American Homebrewers Association Conference

This was my first AHA national conference, but it won't be my last. I left Grand Rapids with so much information to assimilate that I put it on a schedule. I assume that the BOD knows that the braintrust of speaker intellect would compel home brewers to react to all the information they absorbed, and then experiment to an even greater degree, as they seek to  create both unique and common beers that exemplify the pursuit of a great brew. Eventually, craft beer lovers worldwide will be the recipients of it all when they tip future brews that have been influenced by this sort of mind dump.

I hope to shorten the time it takes for an idea to become a liquid. However, I know all this takes more than imagined to be compiled and reiterated in order for the universe of beer to be described as evolutionary.

I gathered some facts from a few educated people that need to be written, so as not to be forgotten. In combination, the findings may change the process of mashing - or maybe not. 

Because I believe that the brew in a bag method will overtake the 3V method inside of the next three years, and because I manufacture The Brew Bag, I had an agenda at this conference. That was to determine if The Brew Bags' filtering capability could be utilized to not only make home brewing faster and easier, but also to discover if the efficiency potential that ALL methods homebrewers use could be increased while also being repeatable.

Most long time BIAB brewers recognize and accept that when they brew high gravity beers (> 1.060), the efficiency will drop off of the norm of 65% to 75%. But they don't know why - it just is!

3V brewers also state that when they brew a bigger OG beer they have to sparge longer (slower with more water) to get close to the normal efficiency experienced with smaller OG beers, and brewer's in both camps just accept a lower efficiency as a trade off to higher OG. 

What is misunderstood by brewers using both methods is that the water to grain (WTG) ratio AND the grind setting are symbiotic - they rely on each other to produce consistent repeatable results. However, the constant factor in both methods, not considered in this drop in efficiency, and the thing that determines the limits of this ratio, is the size of the mash tun.  A batch with more grain in the same vessel increases potential sugar, but it also decreases the WTG ratio and creates a more compacted mash. This compaction prevents the water from flowing freely through the grain bed/bag and thereby taking the sugars with it into the boil kettle. 

Total water volume for 3V/sparge method is very similar to the brew in a bag method and both can produce + 75% efficiency. Ironically, most 3V brewers don't know what their WTG ratio is; they just sparge until the gravity drops or their kettle is at volume.  This simple consideration brings both communities together and explains the common misunderstanding that BIAB suffers lower efficiency; because BIAB is a no sparge method, the brewer's just accepted the efficiency numbers.  The WTG ratio is critical in both methods and conversion is critical - but to the same degree, so is getting the converted sugar into the kettle.

To reiterate: a common myth in the brewing community in general is that brewing using a bag as a filter, instead of sparging (using the grain bed as the filter), produces a lower efficiency. 

I listened to a presentation by Jennifer Heiber called "Know Your Grist". Jennifer is both a BJCP and GABF judge, manages a home brew store, established the QA lab at Boulevard, and is a scientist (I think - sorry Jennifer, I can't find your credentials). She presented results of testing from twelve breweries done by The American Society of Brewing Chemists that determined that mill settings, coarseness of grind, and calibration impact conversion times, and as a result of "typical" timing, efficiency.

Efficiency is the amount of sugars extracted from the grain during conversion relative to the potential available - that make it into the boil kettle after mashing. Read that last sentence one more time and then ask yourself "how do I know what the potential is?' The answer can be found on the label of every grain bag - but home brewers rarely see that label, and if they do, they have no idea what it means. But, that is another blog post.

Jennifer said "stuck sparge" four times during her presentation. And the reason she said it was relative to "too fine" a grind. Meaning, stuck sparges occur in a typical 3V lautering process when the grist particles clog the intake/outflow of the mash tun. The irony of that is, the finer the grind, the faster and more efficient (time) the conversion of starches to sugars occurs. This is due to increased water to grain particle contact. A fine grind converts faster but clogs the mash tun. So, the issue is the filtering capability of the mash tun pick up device.

The solution to a stuck sparge, and thus greater efficiency, is a larger more permeable filter, and that my fellow brewer's is The Brew Bag (or a reasonable facsimile). Here's the thing - The Brew Bag's filter is the entire bag. On average that's 1,618 square (1,200 or so when raised) inches of filtering fabric constructed of 90 threads per inch. By comparison, muslin and paint strainers are about 35 TPI. To give you an idea of the filtering capability of The Brew Bag's fabric, here's a photo of wort taken straight out of the boil kettle. In this case, The Brew Bag was used as the hop bag as well. The cloudiness that can be seen is fats and proteins - not particulates that induce a stuck sparge. 



So if a finer grind can  produce faster conversion and greater efficiencies, why not do it?

After 25 years of active home brewing and the dramatic increase in the last five years or so, why has no one put these two pieces of information together? My undocumented response is that the grind settings/grist size has always been about avoiding a stuck sparge.

The lautering process was developed without consideration of a fabric filter. Until the undocumented UK invention of the bag method, mash tun sparging was the only method employed to extract sugar and produce a clear wort. A slower, more thorough sparge produced greater efficiency as measured in the boil kettle.  

So in the past - coarse grind + slow thorough sparging = greater efficiency. But now, using the  Brew In A Bag method, which is being accepted a viable alternative to 3V brewing that equation can be modified to - fine grind + no sparge = greater efficiency.  

The next blog post will be about a floury grind that produces dough balls and how to avoid them - but I need to do some experimenting with my mill setting first. 


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