Krausen Skimming and Its Importance

[Bryan R]

As pretty much every German brewing texts states, Krausen needs to be removed, the methods usually involve skimming or allowing it to blow off. Well I put this to the test.
As the krausen starts to fall, this is when you should start to skim( if that is your chosen method)
Day 1 of skimming


Day 2 of skimming


Last day of skimming, and beer is about don'e fermenting



Beer was allowed to fully ferment and then cooled down to lagering temp (for me that is 30f beer temp)over a few days . I then sampled the beer. this method coupled with the trub drop, yields a product out of the lagering tank, that tastes simliar to a 3 week serving beer (depending on fermentation methods that could be anywhere from 7-9 week old beer). The refinement out of the fermenter is outstanding. It is now not even an option for my lager brewing(and to be honest I am thinking all my brewing) it was truly eye opening.

[Beersk]

What style of beer was this that you show here?

[Bryan R]

Helles.

[Brody]

Hi Bryan - couple questions:

1) How often do you usually skim, once a day for say 3 days (until the Krausen stops forming)?

2) Any specialized method or is this as simple as using a sanitized stainless brewing spoon and scooping away?

I imagine the process of opening up the FV and getting in there will introduce some oxygen which could be beneficial as well during active fermentation.

[Bryan R]

Hey,

Once a day, until you see no more junk in the foam. I usually wait a few days(so at high Krausen).

Yup, Sanitized spoon. Alternative method would be a fermenter fill that would allow for blow off.

No, no o2 is getting in, its still actively ferementing. You want to keep o2 away from anything but wort being oxygenated.

[pietro]

Do you ever harvest the yeast from the skims? I read a long time ago that these are some of the most viable cells (or at least those best suited for new propagation).

Is there a 30-second answer as to the practical benefits of removing the krausen? What are you removing actually, proteins?

[Roachbrau]

[Techbrau]

My understanding is that krausen skimming is a bigger deal for open fermentations than closed. The bitter resins float to the top because they become insoluable due to the lowered pH; they're not going to dissolve back in a closed system with CO2 in the headspace. What will make them soluable again is getting oxidized, which happens in an open system.

Production breweries in Germany that use tall, cylindroconical fermenters do not skim or blow off the krausen.

Of course, this is at scale with large fermenters that the beer doesn't sit in for very long. It could be a bigger issue for home brewers since our beer sits in the fermenter for a couple weeks usually.

[lhommedieu]

I'm going to try filling my fementer to near capacity and use a blow-off device.

[MaineBrewer]