Low Oxygen Brewing #2

So here I go again talking about low oxygen brewing on the hot side, before fermentation. As I discussed in my last post, one method to eliminate most of the dissolved oxygen (DO) in your strike water is to pre-boil it. The idea here is to maintain the freshness of the grains during the mashing process.

I was looking around some local brewery sites here in AZ and one of the breweries I have a great deal of respect for is Tombstone Brewing. They opened up a satellite here in Phoenix a few years back and every time I go there I am impressed with their offerings. Their Munich Helles Dorado was absolutely fantastic and it seemed to have that certain "IT" quality that true Bavarian lagers have. I also heard that they recently started doing modified Low Oxygen brewing techniques. Could this be related to the awesome beers they were turning out? I did some digging on their Brewer's blog (great resource for beer geeks) and found a possible answer.

Turns out the head brewer did his training in Munich and for years was skeptical of the low oxygen methods based on a study released while he was there finishing his degree. The study seemed to indicate there was no difference between the LoDo batches and the regular batches they tested. So like most of us, he thought it was BS and didn't worry about it. Yet why did all the main breweries in Bavaria go to great lengths to reduce DO?

Six years later, he decided to go back and look at the study again. Apparently the methods used were flawed so the results might not actually be correct. The study had been debunked. Perhaps it would be worth the effort to try harder to reduce DO in their brewhouse.

While I highly recommend reading the whole post, here's a key point he made after re-thinking the method:

Even though we’ve always had very low oxygen in our packaged beer and a relatively good shelf life, I started to wonder if our techniques could be improved even further. Our brewhouse isn’t really set up for low oxygen brewing, but I found a few ways to work around that. Starting in June (2020), all of our beers have been brewed with low oxygen techniques that include completely deaerating our brewing water and purging all the water in-line with co2 to prevent oxygen pickup that might come from a pump or from splashing. As a result, we’ve been able to reduce our dissolved oxygen in our mash tun from about 4 parts per million (ppm) down to about 100 parts per billion.

The results of the shelf life haven’t actually been that surprising… The beers we’ve brewed this way taste fresher for longer. It makes perfect sense because we have been able to carry natural preservatives from the grain all the way through to the canned beer. What has been surprising though is the positive impacts that have occurred with head retention, color, and flavor. When we brewed the first batch, it was immediately clear that there was a difference in the wort composition. Instead of tasting grainy or astringent, the wort tasted bright and distinctively barley-like. It was obvious that we had preserved the nuanced flavor of the barley itself. When we started transferring the wort to the kettle, instead of looking lightly hazy, the wort looked like crystal clear, filtered beer. When we poured samples from the tank, the foam looked dense. But perhaps most surprisingly, the beers tasted “brighter” with a more obvious development of flavor in each sip. It’s not like an entirely new flavor profile, but rather a more refined version of the same flavors. It’s similar to when we all watched DVD’s and thought the quality was awesome, but then we saw Blu-Ray for the first time… We went from tasting in standard definition to high definition.

Perhaps as home brewers it may be worth a little extra time to pre-boil the strike water to reduce DO before mashing in. As for me, I plan to continue to experiment with this concept.....