Filtering protein from the wort

Hey folks,

Is anyone familiar with the details on the amount of protein that yeast needs in primary fermentation? My last few batches have yielded obscene amounts of protein experimenting with acid and protein rests. So when it comes time to rack, I'm forced to choose between drastically reduced volumes in the fermenter (leaving all the protein and about a gallon-and-a-half of wort along with it in the boiling kettle), and arbitrarily deciding when I've sucked up enough protein to help and not harm the beer.

Just to give a bit of context, I brew all grain, fly sparge, and typically boil 90 min (usually adding Irish moss and yeast nutrients in the last 15 min). I've had the same results both decoction and multi-step mashing, brewing anything from a Marzen Kolsch to a scottish export to a bavarian lager. Whirlpooling doesn't seem to work for me (either hot or cold) and filtering from a bazooka-like screen on the bottom of the boiling kettle doesn't do the trick, either. For my last batch (the Bavarian Lager), I just filtered through the screen in the kettle, let the carboy settle for a day at 48 degrees in the lagering fridge, then racked the wort onto the yeast in another carboy the next day.

Any thoughts, suggestions, advice?

- Tom

You're never going to get all of the trub protein out. You did your best with the screen... But the thing is, a lot of people don't even use a screen filter, they just dump everything into primary.

Try brewing batches that are a half gallon larger than your target volume, and don't leave behind a bunch of wort just because it's a bit chunky

Discussions of a more scientific nature that I've read usually say hot break protein is no good and cold break is thought to be possibly beneficial to yeast health. So I religiously skim the break from the boil at the start and allow most of the cold break into the fermenter because frankly with a plate chiller it's easier to let it go then filter it. After several days of cold crashing it compacts to a much smaller amount than you original perceive it to be.

The rest at 100F or so proved to be a problem for my system and created crazy amounts of gunk/proteins & break so I stopped doing them.

My advice is to do as Reno above suggests and brew a larger batch if you need to net a certain sized batch.

samc said:

Discussions of a more scientific nature that I've read usually say hot break protein is no good and cold break is thought to be possibly beneficial to yeast health.

Click to expand...

I've never heard that before. Can I have a source or link to the article you read, please? I mean no disrespect, I'm just in the sciences and citations are all I trust

samc said:

The rest at 100F or so proved to be a problem for my system and created crazy amounts of gunk/proteins & break so I stopped doing them.

Click to expand...

Protein rests are only necessary when using grains with high amounts of proteins that cause chill haze. Unless you're doing protease rests for wheat/rye/undermodified grain, you won't really see much benefit.

BT - Cold Trub: Implications for Finished Beer, and Methods of Removal

I was doing a rest to enable PH adjustment, more of an old technique that some still practice. I've never done a protein rest and with my usual IPA/PA brewing I doubt I will need one. Maybe if I up the % of Rye in some of my beers I might consider it.

Nice, thanks. But what I meant was I have never heard of hot break proteins being detrimental

I misspoke (mistyped?) my intent. I've read the good of cold break and discerned the bad of hot break by taste. If you skim the hot break/foam and taste it you realize that you don't want that adding to the flavor profile of your beer. The same way I don't want the foam from a pot of chicken soup or the scum from cooking a pot of Lentils.

Now having said all that I did a search to see if my thoughts made any sense. Hot Trub: Formation and Removal

Many thanks!

The article from BT was great. So far, I have to confirm his conclusions there: less cold trub, longer lag in cold fermentation...probably not enough data to build a rule around, but helpful to look out for in any case.