How To: Lager Fermentation

3 Ways to Ferment Lagers

Interested in making lagers but don’t know where to start? Have you been told that lagers are too difficult for beginner or intermediate homebrewers? Here are 3 methods (plus a bonus!) to ferment lagers.

Method 1: Slow and Steady

The “traditional” way of fermenting lager is a slow process. And it requires a bit of patience! And dependable temperature control.

1. Chill the wort to 9–10 °C (48–50 °F).
2. Pitch the yeast and maintain the temperature for 2 weeks.
3. Raise the temperature over several days to 18 °C (65 °F) to perform a diacetyl rest.
4. Slowly lower the temperature by 1 °C (1–2 °F) per day to near freezing (for American style lagers: 1–3 °C/33–37 °F; for European styles 5 °C/41 °F).
5. Keep beer at this temperature for approximately 4 weeks or longer.
6. Package and carbonate the beer.

From “grain to glass” we’re talking about about 7+ weeks!

But there are other ways of making lager! Let’s look at a quicker version next.

Method 2: Picking Up Speed

For a bit quicker turnaround of your lager, you can follow one of the fermentation schedules from Professor Ludwig Narziss. One such schedule is as follows:

1. Chill the wort to 9–10 °C (48–50 °F).
2. Pitch the yeast and maintain the temperature at 10 °C/50 F for 3 days.
3. Raise the temperature to 13 °C/55 °F and maintain for 3 days.
4. Raise the temperature to 16 °C/60 °F and maintain for 2 days.
5. Raise the temperature to 18 °C (65 °F) and maintain for 2 days.
6. Check the gravity with a hydrometer to see if the target final gravity has been reached.
   • If so, package and carbonate the beer.
   • If not, maintain the temperature at 18 °C/65 °F for 2 more days and check the gravity again. If the gravity hasn’t changed, proceed to packaging.

With a Narziss-type fermentation schedule, you can have a lager in your glass as soon as 2 weeks! What a time-saving method!

Method 3: Pedal to the Metal

A third option is to ferment a lager “warm”—that is at ale temperatures.

There are two variations of this method:

1. Chill the wort to 9–10 °C (48–50 °F) and let fermentation naturally rise to ambient (room) temperatures.
2. OR Chill the wort to 16–18 °C (60–65 °F) and maintain temperature throughout fermentation.

Especially with yeasts like Fermentis SafLager W-34/70, Lallemand Novalager, or White Lab WLP800 Pilsner Lager yeast, the flavor profiles produced by these yeasts are clean and neutral, even when used at fermentation temperatures. And back in 2015, Marshall Schott at Brülosophy performed an exBEERiment investigating whether or not tasters could distinguish a Bohemian Pilsner fermented cold versus warm. This showed that only 13 out of 39 participants could pick the odd beer out in a triangle test, suggesting that there was not a statistically significant difference between the two beers.

The beauty of homebrewing is that it’s your beer to experiment with.

If you like what’s in your glass, you’re doing it right.

Bonus Method: Feel the Pressure

If you really want to have an insurance policy to prevent unwanted off-flavors, ferment the beer as in Method 3, however, use a pressure-capable fermenter like a Corny keg or unitank. I would suggest using 10-12 psi, but no more than 15 psi (~1 bar) of pressure.