Cold Fermentation method keeps failing me (stalling)

[Owenbräu]

There may be other factors in play too. Have you had these problems with non-lodo lagers?

Have you calibrated your thermometers? The ones on my kettles lose calibration every 5-10 batches, often by 10 degrees or more. My boil kettle reads about 40F past 212F no matter what I do. You could be dough-in and mashing much warmer than you think and losing fermentability.

How fast are you stepping the mash? I have lost fermentability (and I think Bilsch experienced this too) by heating the wort too fast as well as by not recirculating fast enough and getting stratification under the false bottom. This will decrease fermentability too.

How much carapils or crystal malt do you have in your recipe? Both will reduce fermentability.

[Nick_D]

[Nick_D]

[Nick_D]

I'm actually about to make a fresh starter for my next attempt as suggested by Techbrau. A little over 1/4 cup of dense slurry, in 4 liters of 10 plato starter wort. Fermented at 10C for 3 days (with shaking as often as I can), then crashed. I'll use it the next day. Should yield me around 450 billion cells. Does that sound about right?

I'm hoping the fresh yeast, some good oxygenation at pitching, and not shocking the yeast when cooling will get me to a better result.

[Owenbräu]

Let us know how it goes.

[Nick_D]

[Nick_D]

[Nick_D]

Update:

So in the last 2 days, it has only dropped 1 point to 1.020, which is disheartening. Air lock is still active, and there is still thin krausen on top. Beer is still nice and cloudy, so the yeast haven't flocc'd out on me, which is something at least. Currently at 5.4C, and won't drop the temp any further from here at this stage. At this rate it will be almost a week before I can transfer to spunding. I'm not worried about how long it takes, just want it to be a success. Has anyone else had it go this slowly, and be successful ?

[lupulus]

Sorry. Why are you using this (cold fermentation / cold maturation) method? The method is certainly in the textbooks and used by many, but your yeast management and temperature management should be perfect, and this is not easy.
There are many breweries that ferment differently with excellent results. Augustiner, which many consider the gold standard in Helles, ferments high and under pressure. I am of course, not suggesting you do this, but that you keep it simple until you get a very good beer and then start tweaking.
Why not start with the same process you are using but keep it at 9-10C until final gravity, then slowly go towards lagering temperature and then lager?

[Techbrau]

There is no lagering happening if FG has been reached and the yeast have already gone dormant. The purpose of racking to the lagering vessel with extract and active yeast is, among other things, to scavenge oxygen and provide natural carbonation in the lagering vessel. If you haven't yet read this, I suggest it:

http://www.germanbrewing.net/docs/Brewi ... Helles.pdf

As far as the accelerated ferments go, I'm not sure they're well suited to making good lager at home. The textbooks that we often cite around here (Narziss, Kunze, Annemuller) that describe the accelerated fermentation schedules only recommend them for ZKVs, which are fundamentally different from our small fermenters because of the enormous hydrostatic pressures they exert on the yeast, which effectively counteract the heightened temperature. For traditonal shallow fermenters, every single one of those authors recommends only two lagering schedules: the traditonal warm and the traditional cold. I saw an immense improvement in my beer when I went to the traditonal schedules and I know many others here did as well.

I'm not saying that you can't make beer by fermenting at 14c and maturing at 20c. You will of course more reliably reach the attenuation limit with an accelerated ferment, especially if you underpitched, used unhealthy yeast, or if your wort lacks sufficient nutrients. But you will more reliably make good lager with the traditional ferment.

If you do choose to ferment to final gravity in the primary vessel and care about keeping oxygen out of the keg, you need to krausen with active yeast when you rack.

Nick_D, how are you measuring your gravity? Are you sure you're getting an accurate measurement? I often see my fermentations significantly slow down around 1.014-1.015 but they eventually make it down to 1.010 or 1.009 over a couple weeks. If you're seeing activity, I think you're okay; if it really does stall, in an emergency you can add some additional actively fermenting yeast.