Experimenting with LoDo: Rolling Updates

Today I'm brewing the first beers where I'm trying not just to avoid hot side oxygen, but to eliminate it from the process. Although I'm doing this on a 15 BBL commercial system, I thought I would share this here since it comes up from time to time. Some background:

In 2014 I attended the World Brewing Academy at Siebel in Chicago and Doemens in Munich. Our course curriculum was originally based off of Technology Brewing and Malting (Kunze). I read that book as we went through our lectures each week. In Chicago, one of our teachers (John Mallett) had told us reasons that Bell's was using low oxygen brewing techniques. It had mostly to do with shelf life of the beers. In the textbook, Kunze mentions on several occasions that oxygen is bad for beer at any point other than wort aeration and he does mention that harsh flavors arise from hot side aeration. Then in Munich, we were told by a professor that they experimented with aerating mash and throughout the lauter and they couldn't tell a difference between beers brewed that way and beers brewed with "normal" techniques. I trusted the German professor since they had done a true side by side and I took that to mean that the HSA stuff was insignificant. I've always tried to avoid excess oxygen pickup, but never tried to eliminate it. One thing I didn't think about though was that the German professor didn't say they eliminated oxygen... They brewed one beer with their normal brewing practices and another with a lot of oxygen and I hadn't really thought about that until recently.

More recently, I started experimenting with my lager techniques since I've brewed lagers basically one way for my entire brewing career... Basically always with Augustiner yeast, a slightly ramped fermentation temperature towards the end of fermentation, 3-4 week lagering period, etc. I have always been very happy with those beers, but then I decided to experiment with pressurized fermentation to reduce esters, other yeast strains, some new malts, natural carbonation, etc. All of that reminded me of a slightly contentious exchange between myself and an inactive forum member (Beerery) and I decided to reach out to him and ask him more questions about some of his yeast handling techniques that I thought would scale well to the commercial system. He's not a guy you can talk to without broaching the LoDo subject. I had also just started reading Kunze again and was reminded of all the times in which Kunze says to avoid oxygen in the mash, lauter, etc. So I thought I'd give it a shot to eliminate oxygen rather than just avoid it's pick up.

One other thing that lead to this decision to try this: Years ago a mobile canner called me and asked about an observation he had made. A brewery that he was canning for would sometimes have very low dissolved oxygen levels in their brite beer tank and when they did, their canning line would introduce less than 50 ppb total packaged oxygen. If the brite beer tank was above 30 ppb dissolved oxygen though, the canning line would introduce over 100 ppb total packaged oxygen. It appeared that oxygen pick up was exponential. I recently observed the same phenomenon while doing consulting for a brewery. While I was reading Kunze, I was thinking about sulfur is an antioxidant so it would protect the beer in a transfer, but then the sulfur is gone and can't protect the beer any longer. I started wondering if that was the reason we were seeing this oxygen situation. Then I started thinking about the other things that protect beer... ascorbic acid, tannins, polyphenols, yeast... What if we're destroying ascorbic acid and tannins with oxygen in the mash and thus taking away a layer of protection? I can't say I'm educated enough to know if that's even a reasonable question to ask and I don't have a good way to test that theory, but thought that I definitely won't hurt anything by eliminating hot side aeration, in a good situation I'll have a better shelf life, and in the best case scenario, I'll do it and find that the flavor of the beer is improved. If there's no downside and potential upside, might as well try it right?

Disclaimer: I'm simply going to list observations and beliefs, not setting out to prove anything. My data should be observed as simple data points, not scientific facts and I would hate if anyone tried to use my information as a conclusion to any debate surrounding the topic. I won't be able to do a side by side with a beer brewed using our "normal" techniques. 2 of the 3 beers I'm brewing today (Pils, DDH IPA, and TIPA) are new recipes. DDH IPA will be one that I remember well, but I won't have a side by side blind tasting available unfortunately.

I started off today by deaerating my hot liquor tank. I boiled it yesterday actually, let it cool overnight, and when I got to the brewery this morning it was at 164F. I measured the DO at .6 ppm (normally we are at 3.5 ppm). I hooked up a venturi aerator inline to the mash tun and connected co2. The water coming out was reading at .1 ppm and I added a small amount of Antitoxin SBT which is a potassium metabisfulfite, ascorbic acid, and gallotannin formula. My mash temperature was 149F with 100% Pils Malt. The DO of the mash was .3 ppm (normally 4 ppm) after mashing in and stirring. I checked the DO in the lauter and it was reading .1 ppm in the receiving kettle. I observed a few things:

-The clarity of the wort was VERY good. Normally, I think of our wort as being good. This looked like filtered beer though.

-The wort is possibly slightly paler than normal

-Tasting the wort was the big surprise. I tasted no astringency at all, and I normally do not drink wort because I don't like the astringency of fresh wort. The sales rep for the company that sells the antioxidant that I used said that we would get more bright grainy flavors with the elimination of oxygen... I thought it was BS to be honest. But upon tasting it, I could see how someone would describe the flavor as brighter.

-I aerated the wort inline to the fermenter knocking out at 43 degrees F. Active Imperial Organic L02 Fest (Wyeast 2206 equivalent) was waiting in the fermenter. The wort was aerated to 10 ppm and 1 hour later, the DO was reading .8 ppm suggesting that the yeast has nearly reduced all the oxygen in the hour since knocking out.

I just started the second batch of the day, DDH IPA. It's a hazy with flaked oats and flaked wheat. I've observed the same basic things... slightly lighter color than I'm used to. Better clarity (though with the oats and wheat, it's not great clarity), and a less astringent wort flavor.

I'll be updating this thread as the beers progress with my thoughts and impressions. Feel free to ask questions.

 

Yeah, the idea is that I’m trying to scrub out the last little bit of oxygen. There’s splashing in the mash tun so the sulfites are keeping us from going back up high, but I wanted to make sure the water was as low as possible so the sulfite wouldn’t have to do much work

 

I forgot to list the recipes:

Pils is 100% Weyermann Extra Pale Pils Malt. I used Bravo hop extract to get us to 18 IBUs and a whirlpool addition (most homebrewer's equivalent of a 20 minute addition) of 1.5 lbs/bbl of French Strisselspalt. I will dry hop with .75 lbs/bbl of French Barbe Rouge. Fermented with Imperial L02 Fest at 44 degrees, spunding, and naturally carbonating.

DDH IPA is mostly Maris Otter with Flaked Oats and Flaked Wheat. 3 lbs/bbl of Citra and Amarillo in the whirlpool. 4 lbs/bbl dry hop with Mosaic, Comet, Citra, and Amarillo. Fermented with Imperial A38 Juice.

TIPA is the same malts as IPA, but more and dextrose added to help dry it out. 4 lbs/bbl Citra and Comet in the Whirlpool. 6 lbs/bbl dry hop with Strata and Citra. A38 Juice for yeast.

 

A lot of commercial brewers don’t do whirlpool (or any hot side) additions on their hazy IPA’s these days. I think you miss out on a “full” hop flavor if you brew that way. For the Pils, that’s a pretty big whirlpool addition, but it’s sort of taken from what I was told Augustiner does with their pils which I love... basically a hopbursted Pils at 33ish IBU. Normally my bittering addition is smaller or nonexistent but for this beer, I wanted a sharp, fast bitterness that vanishes as quick as it comes. I don’t lower temps for my whirlpool.

I don’t do an extended boil but for beers with Maris Otter, I’ll start my boil timer immediately when the boil starts and for Pilsners, I’ll wait until I have a full hot break to start the timer.

 

Back in 2014, John had told our class that Bell’s was eliminating hot side aeration with a nitrogen purge on the hot side vessels. Whether or not they deaerate their strike water, I don’t know.