View Full Version : filtering cold trub

Chip Tate
11-13-2003, 12:00 PM
I have a crazy idea that I've never tried and it just occurred to me that some else may have (or something similar). Many brewers use a hop back to filter hot trub from wort, but what about using something similar to filter out cold trub?

The idea would be to steam sanitize just enough whole hops to form a filter bed and run the wort through this "cold" hopback post-heat exchanger and pre-aeration/oxygenation.

I can think of many reasons one might not do this: 1) Don't want to bother with cold trub 2) cold trub much smaller than hot trub--wouldn't filter well 3) flow-through too slow, etc. --but it might work and might be worth it for those really delicate lagers.

Does anyone else who tries to remove cold trub have experience with something like this?



11-13-2003, 02:15 PM
I assume you mean a post-heat-exchanger filter of sorts.
Besides the sanitation risks of such a device, as your running off your wert, the filter starts to fill and resist, slowing your flow and throwing off you run-off temps.and time.
Besides, a little cold trub is good for the yeast.
If you still feel your running off too much trub, getting creative with some kind of passive dams in your kettle is your simplest soloution.

good luck

dick murton
11-14-2003, 09:27 AM
As stated previoously, a little trub is useful as a yeast nutrient and also form focal points for CO2 eveolution, which is what stirs the fermetnation up to ensure even temperatures etc. If you are producing so much trub that it is smothering the yeast and causing low foam retention and poor yeast growth etc then it sounds like too much hot trub. The cold trub should be basically proteing, in small enough quantities not to affect yeast. If you are getting too much this points to poor mashing regimes, poor wort boiling, or more likely hot break formation (which can be poor boiling, wrong pH, slow whirlpool rotation speed or simply not allowing sufficient time for trub formation) Check ionic composition especially calcium, and consider using copper finings -carageenan, seaweed extract.

Potential horrible infection problems cold filtering thru hops - urghh


Chip Tate
11-14-2003, 02:46 PM
So it sounds like the consensus is that cold trub removal is not really necessary even for delicate lagers? Would you also say that German methods such as flotation tanks are really unnecessary steps then, even for that kind of beer?

Points well taken about the risk of infection from hops. I was proposing to sterilize them with steam, but this is still a real risk to worry about, I agree.



dick murton
11-16-2003, 11:05 AM
You will never remove all the cold break as it takes several hours to form after the wort has been cooled, so filtering it is not realistically an option then - it should be starting to ferment, with the yeast starting to grow by then. For a micro, I would expect to see greater returns on flavour stability by choice of suitable malt, careful mashing & lautering control, and oxygen control further down the process than spending money on wort centrifugation or filtration. Don't forget also that filtering through hops will not remove as much hot break as centrifugation or KG filtration, and you may get some additional flavours, possibly undesirable as a result of heat sterilising the hops themselves. I also consider that contact with large amounts of hops adds a certain fullness in flavour, sometimes I have described it as vegetable richness, not DMS though - but something that I consider quite pleasant if at lowish levels and consistent. Certainly beers I have brewed have changed character with changes in the volume of vegetable matter, even though the IBU in final beer was exactly the same - almost marketable as different beers (same late hops / dry hop added - just different bittering hops)


Larry Horwitz
11-24-2003, 06:16 AM
If your really worried about cold trub, and you use Unitanks,
drop it from the cone in day 2(ish) of fermentation. The
yeast will get what it needs from the trub, and you'll also be
cropping dead/early floccing yeast. Works for us.

02-14-2004, 01:46 AM
I agree with everyone. You can "relieve" the cold break from the cone about 12-24 hrs. after last knock-out. However, it is believed by some that cold break is useful for yeast growth (it provides unsat. fatty acids needed for cell membrane synthesis). So I would say don't worry about it and remember that hot break and cold break are esentially of the same composition so limit the former to decrease the latter; i.e., good boil, whirlpool and draw-off technique. Absolutely no high tech stuff needed and no microbiologically risky "reclaiming." Good topic...cheers to all!!!