Logistics of warm lager fermentation for homebrewers

[Brandon]

I just saw a thread on FB about Mike's lager talk...and the warm lager fermentation schedule. Not zeroing in on Mike, it just prompted me to post some thoughts and a question.

Since switching to brewing lodo, I feel like I have been looking at fermentation more as a tool to preserve flavor and manage oxygen throughout the process, not only 'turn sugar into alcohol'. Using a cold fermentation and spunden I now have far better control over managing flavor development and oxidation protection as the beer moves through the process.

So in the context of oxygen management (not to mention smoothness of flavor and fermentation character) it seems to me a warmer fermentation schedule makes less sense for a homebrewer. For a big brewery that can dial in fermentation pressure to suppress esters, and can do excellent closed transfers via gas purging, I'm sure it works (as it is commonly used). But the schedule seems to neglect unique issues homebrewers have where the cold ferm/spunden makes a lot of sense.

If you ferment starting warmish (10C), then keep going up, at the end of fermentation you are left with a warm beer at FG in a fermenter (carboy or similar for a typical homebrewer). How do you transfer it without introducing oxygen and oxidizing the beer? Seems like the beer is totally unprotected and has no defenses (including benefits from sulfur). And in my experience, I've burned much of the flavor out of the beer at those temps. Never mind preserving the malt flavor of a lodo mash and tuned boil.

And if you crash (or even slow) cool it, pressure differential changes and for many folks the cooling sucks air into the fermenter.

If you have appropriate equipment to manage fermenting under pressure, purge lines and assure no oxygen ingress, it may work, but I would think that is more work to design for vs cold fermentation in the first place.

I'm on my 4th cold/spunden fermentation now so will post more thoughts and experiences as I have them, but using a 6.5g keg, fermenting in my lagering freezer with heater and Brew Pi temp controls, I can chill to 7C, pitch and manage temps quite accurately up and down. These most recent beers never warm past 10C (now staying lower since I can pre-chill colder), so I can slowly drop temps for secondary and take a nice gradual ramp down. I have 1 beer that finished up and is now at freezer temps, one that is in secondary and holding, and one that is actively fermenting from brewing earlier this week. And I freed up an entire freezer.

What are your thoughts and experiences with the different fermentation temp schedules?

[mpietropaoli]

I do not have any direct experience with this (yet), but I think the discussion should be expanded to include ale brewing.

Our first lodo (helles), we had two big cold-side mistakes (1) transferring to spund too late so we had to force carb and didn't have much pressure in the valves and (2) didn't purge the line of O2 for the fermenter>keg transfer so there was easily a shot glass worth of O2 in there.

I only mention this because our second stab was with an ale we brew that is very lagerish (viewtopic.php?f=13&t=319), more of a hybrid, or Filsner as we call it. The yeast has some ester production at this temp, but it honestly works really well in the overall flavor profile of the beer. I bring this up because the same issues/concerns exist, particularly blowing off the volatile malt phenols we worked so hard to keep.

We pitched at 60* (4 sachets of US-05 into 14 gallons of 1.050 wort) on Sunday June 5th, and by Wednesday June 8th, we were at ~1.017 and transferred to spund. We are spunding at 65* and 30psi per Bryan's recommendations on his ale brewing. Our plan is to hold it here for a week, then drop down 3-5* per day to serving temps.

[Bryan R]

Here is a graph of my modified lager fermentation that I used to use, I probably brewed 500 batches using this.


For this beer it was pitched and fermented at 54(green line). If you follow the orange line you will see a reverse mountain peak that is fermentation driven and the lowest peak of that is the height of fermentation. Right after it starts to slow down, I would let the fermentation free ride to where it would naturally stop. I would then check beer for Gravity and flavor, then I would cool the beer back down to lagering temps. When lager temps where hit it was then transferred to the lagering chamber.

Now when I was making oxidized beer, this method worked fantastic, there where no off flavors to speak of, and all was well. Once we started realizing things it only took 2 goes at cold fermentation and spund to make me a total convert. The only reason it took 2 is because I wanted to believe the first one was a fluke.

Don't forget all the Narziss accelerated profiles ASSUME CCV's and pressure. One can not employ this warm technique and preserve what you worked so hard to keep. Trust me, I really tried to make it work.

[Brandon]