Fermenting lagers in 21 days

Traditional fermentation techniques have a few downsides.  Time being the most obvious one, and with time comes the additional requirements for storage space.   There are also some process specific pitfalls which mainly revolve around yeast health.  Carrying too much yeast into secondary, abrupt temperature changes as well as unhealthy yeast (low viability) can all result in autolysis.

Once autolysis happens the contents are irrevocably destroyed.  It happens far quicker than many suspect.  Controlling pH during fermentation is important since it is a good indicator of things going wrong.  A rise in pH is bad news.  If this happens then the usual causes are mainly infection or autolysis.

Other pitfalls can include incomplete decomposition of by-products during a poorly conducted secondary phase.

Annemüller suggests an accelerated fermentation schedule, starting cold, then conditioning warm.  In essence the equipment needed is not different from the equipment for classic fermentation and thus suitable for home brewers without requiring further investments.

Here is how to do it

1. Primary Fermentation (Hauptgärung)

Until the yeast growth phase is complete the fermentation proceeds just like with the classic schedule.

  • Pitch temp 6°C
  • Ferm temp 8°C
  • Duration 2-3 days

However, once the growth phase is over (high Kräusen), the temperature is then allowed to rise to 9..10°C for a further 2-3 days until between 1..2.5% residual extract is left to ferment.  Note that this twice as high as during classic cold or warm schedules.

  • Ferm temp 10°C
  • Duration 2-3 days
  • Transfer (Schlauchen)  ΔEs 1..2,5%

2. Secondary Fermentation (Reifung)

Transfer has to happen into a vessel capable of withstanding 2-3 BAR pressure since the resulting settings on the pressure relief valve will be much higher.  Since home brewers ferment often in soda or beer kegs this should not pose a problem for many.  If your outfit is a microbrewery, then I’m afraid an investment in a pressure tank may be needed  at this stage.

  • Ferm temp 10..15°C
  • Duration 3..7 days

The pressure relief valve is set to the desired carbonation level and the maturation happens over the next seven days at 10..15°C.  Some brewers opt to step the pressure settings in order to reduce the formation of by products even further.

3. Cold Conditioning

After the secondary fermentation is complete the beer is transferred (Umdrücken) to yet another vessel whose temperature is at 0..3°C.  Since maturation is complete a yeast shock from the sudden temperature drop is not expected.

  • Temperature 0..3°C
  • Duration 7 days

Now the beer undergoes it’s cold conditioning phase where it spends a further 7 days before it is filtered or fined.



  • [GAHM] Gerolf Annemüller, Hans-J. Manger.  Gärung und Reifung des Bieres (2. Überarbeitete Auflage).

Towards a Modern Mash

I am still in persuit in the production of outstanding Bavarian brews at home, even though the rate at which  I publish my notes is not as frequent.

The main reason for the relative inactivity is that the topic now requires a lot more empirical evidence.   This is time-consuming and often a trial is not producing the anticipated result, which made it necessary to return to my textbooks from Narziss, Back, Kunze and Annemüller and dig deeper into the reasons and mechanism of this complex machinery known as “the brewing process“.

Thankfully I also have friends who are just as enthusiastic about Bavarian beers and together we were able to make good inroads.

The topic of mashing always attracted a lot of attention.  When talking with friends who are also keen students of the very same texts, I noticed that, malting apart, the process can be divided into three principal sections

  • Phase 1: Wort Production
  • Phase 2: Fermentation
  • Phase 3: Stability

Each of these phases is a huge topic on its own.  Stability is probably the most underestimated in home brewing circles (believe me, nothing is as upsetting as seeing an incredible Helles suddenly deteriorate).  Stability is likely the most difficult as well since the necessary products are generally not available to home brewers or are simply unsuitable.
Back to modern mashing…

It may surprise you that I stopped decoction mashing for various reasons.  The biggest reason is that, time apart, the process is energy intensive and introduces too much air into the mash — which is undesirable for Bavarian brews.

Naturally,  a professional system will transfer the mashes from below.  That’s for decoctions as well as for filling the sparge tuns. Scooping simply introduced too much air.  If you think oxygenation  is not a problem in mashing, then I recommend obtaining a copy of Kunze in English, or Die Bierbrauerei: Vol II, where the negative effects are presented with plenty of data to support it.

One can also clearly notice oneself.

Mashes which are oxidised have the following characteristics

  • Darker wort
  • Coarser taste
  • Lower stability

Therefore wort production for the home brewer needed a little re-think.

It is not out of reach and is achievable with slight modifications to the routine.  It is a process that can be gradually improved (I’ve done this since last October).   There are simple steps one can adopt immediately to see an improvement.  Later one can refine it further.

Ironically I’ve ended up with a no-sparge system but with an agitator setup.

More about this later.


DIY Digital Hydrometer Project

DIY brewing

I have wanted a digital hydrometer for some time now. It would primarily be useful to know the gravity of the beer to know when fermentation is complete, or if I wanted to leave a couple of points unfermented, depending on the style. I don’t like taking samples and using my standard hydrometer – it wastes the beer, it takes time, and it compromises the beer hygiene. Imagine just being able to quickly look on the laptop or smartphone what the gravity is.

In the last couple of years I know of two products that can be bought, namely The BeerBug and the Tilt.

These both look like great products and I would be thrilled to have one. But these cost a reasonable amount and I figure I could probably do it myself for cheap.

I had thought for a while to base it on measuring the change pressure…

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