Effect of Skimming the Fermentation

[bobtheUKbrewer2]

Ignoring possible infection risk, what is the effect on the finished beer of skimming off the brown / black sludge that tends to sit on the surface of the 2 inch creamy white head during the first few days of fermentation ?

Personally I cannot see how letting it settle and sink into the fermenting beer can give beneficial properties to the beer, so I skim twice a day for the first few days.

 

[Ski12568]

I read this today:
"The reduction in solubility of hop acids can be seen during fermentation. After wort is pitched with yeast and the pH falls during fermentation, most of the unisomerized hop resins will come out of solution again. They become part of the brown gunk that floats on top of the Kraeusen which, if a smooth bitterness is desired, should be removed via blow-off tube, skimming and not allowed to fall back into the beer [Narziss, 2005][Kunze, 2007]."
http://www.braukaiser.com/wiki/index.php?title=How_pH_affects_brewing

 

[bobtheUKbrewer2]

thanks, Ski. Very useful.

 

[wobdee]

I've thought about skimming that scum but I've noticed by the end of fermentation it seems to stick to the side of the fermenter and possibly doesn't fall back down into the beer.

 

[wilserbrewer]

When I toured the Carlsberg brewery in Denmark years ago, I recall a brewery worker dressed in white using what looked like a swimming pool tool cleaning with a long pole to skim the wort in the fermenter, which was open and resembled a swimming pool sunk in the floor behind a glass wall.

 

[beergolf]

The bad things outweigh the good things at the homebrew level. Commercial brewers are top copping the yeast. On the homebrew level it opens up the brew to infections.

I would not do it, but if you think it works for you, then go for it.

 

[Ski12568]

No risk with a blowoff tube, just gotta hope the yeast are going crazy, or use a slightly smaller primary.

 

[RM-MN]

When you have a small fermenter, much of the "sludge" gets stuck to the side of the fermenter. When you scale that up to a fermenter that is 10 to 20 feet in diameter that sludge may not make it to the side to get stuck so the breweries "help" it a bit by skimming. There are a lot of differences in the brewing processes from a big brewery to the much smaller home breweries.

 

[funnelweb]

I have never ever heard about skimming the wort during fermentation. OK! Braukaiser who linked to this information could be really good to get into this discussion?

BR Folke

 

[Warthaug]

It used to be common practice among many of us in the 1990's; its since fallen out of favour. I didn't notice any real difference* when I stopped doing it.

Bryan

*Not that I was looking real hard

 

[bobtheUKbrewer2]

I even skim the wort as it warms up just before boil - before the hops go in!

 

[TrevVB]

I heard/read something about skimming the wort. Maybe something about clarity. I plan on trying that for my next few batches.

 

[wobdee]

I heard/read something about skimming the wort. Maybe something about clarity. I plan on trying that for my next few batches.

I've read the Germans skim the hot break and that's what I do as well. I don't like the looks of that brown scum and don't want it in my beer. Chefs skim they're stocks as well so maybe there's something to it.