Filter cold crashed wort, reheat to pasteurize before pitch

[fearwig]

I know this isn't the first BIAB filtration thread, but there's a twist here so bear with me. I'm about to start my first BIAB after one (so far) successful fly sparge batch, and I'm thinking that my fly sparge wort was trubby enough to begin with, so I've been thinking:

Why not cold break your (finished) wort, filter however you want, then return to kettle, bring to temp (maybe 180F, well above pasteur temps)? Then add to fermenter hot and wait for it to come down to yeastworthy temp and pitch.

It seems to me like filtering post-boil wort is begging for bugs, but I don't see why (pre-pitch) boiled wort should be treated so gingerly that you can't bring it back to temp after you get out the coagulated trub via filtration. Just need to take care not to aerate hot, if you believe in that sort of thing.

Am I overthinking it? It seems like people do crazier things to clear trub, but removing all those proteins from cold crash (even the finer ones) seems like it would take you a long way. You could even use something fine like a coffee filter, since you have eliminated contamination/time considerations.

 

[Weezy]

Sounds too much like work to me. Have you had infection problems? Have you had hazy beer due to poor removal of cold break? If no to the those questions, I wouldn't be looking for solutions to problems you don't have.

A nice solution (if you have the cash) is to use a jacketed conical and rack hot to it, cool in the conical, and dump the cold break out the bottom before pitching.

 

[fearwig]

No infection issues, but I didn't do any kind of real filtration on my fly sparge batch (just ran it through a strainer to get the extra leaf and stray husks out).

 

[Carlscan26]

Unless you have a SS fermenter racking hot wort into your fermenter is a recipe for disaster - thermal shock if its glass and melting if its plastic.

 

[fearwig]

Well, HDPE (#2 symbol) won't melt at 180F or even 212F (it's "safe" up to 250+). That's the material for basically any bucket fermenter, even if it's a HD bucket. I wouldn't risk a glass carboy experimenting but if I had even odds I'd bet you'd have trouble cracking it at 180F too since the flow rate would be limited to the neck/tube.

Now if someone's fermenting in some LDPE like a rubbermaid I guess it will go soft, but I hope no one does that. Mmm, phthalate beer. (OK, I did do this in college.)

I think Weezy's basically right that you shouldn't fix what's not broken, but I do think it's less trouble than 99% of the things people do to get trub out of their wort, and you can filter it as fine as you want before you pitch with (as far as I can tell) no consequences.

 

[fearwig]

OK, experimentation yields results (along with some long-delayed common sense). The real reason you don't do this is that the reheat will throw off your hops. You could compensate with an addition during the re-heat, but you basically have to rethink your hop additions from scratch.

I was wondering why my beer came out bitter when I had a small 60min addition.

 

[kh54s10]

Don't put hot wort in a Better Bottle: https://www.homebrewtalk.com/f11/psa-dont-put-hot-wort-into-better-bottle-pic-350639/

Don't put hot wort in a glass carboy. Even at the lower heat described the thermal shock could cause problems. We don't want to see more pictures of stitched after another broken carboy disaster.

IMO this is reinventing the wheel. I get good results without filtering, cold crashing, pasteurizing or any such. It is just not worth the hassle for such little change. Trub settles then careful siphoning is plenty. YMMV.

 

[fearwig]

I get what seems like a lot of protein from my biab setup. If I can keep that convenience while sacrificing less wort to trub, I call that a win.

My plan this batch is to try a 5-micron filter bag on the last 1/4 of the wort post-cold crash and see if more of it is reclaimable. I'm also going to test mash ph this time, I understand trub volume is much higher when your mash leans alkaline.

Yikes on the better bottles, btw. A HDPE brew bucket won't ever do that (unless you pour in fry oil or something I guess), but point taken.

 

[fearwig]

The 5-micron filter bag is a beast after the mash. If you do more than a few gallons it will slow and need a rinse, but if you want to clarify those proteiny dregs it will turn them into clear, sweet wort in minutes. A nice big bag (half gal?) was $7 on amazon.

I filtered half my volume, plus any cloudy dregs. I'd filter it all except I think I might strain out the head/body protein that way. Worth some experimentation, though!

 

[BigFloyd]

I do recirculating E-BIAB and the chilled wort going into my bucket is pretty darn clear. Whirlfloc @ 10min and then a post-chill rest of 15-20 min to allow the gunk to settle before transfer are the only extra steps before pitching. Later, I cold crash the primary 5-7 days at 35-36*F before bottling. Not much extra effort and I like the result.

 

[Kahless]

I just stir for a few minutes to create a whirlpool while cooling, and then syphon off. It's really easy. However, I do worry about losing some wort to the poorly compacted cone of trub. I was thinking about buying some incredibly fine SS mesh filter and making a giant french press set up for the boil pot! But for now i'm just accounting for any loss in the recipe, as it's not much and it's still good beer in the end.

 

[fearwig]

Yeah, I steam sterilized the cheap 5-micron singed poly bag I mentioned above and used it to reclaim all but the sludgiest part of the trub before primary. I got an extra quart of wort out of it for each 5 gal batch. That might sound petty, but would you pour 2-3 beers down the drain each brew? You just hang the bag over the fermenter and pour in the trub. It will block up a little but it will slowly filter out even when it's stopped. Even heavy sludge comes out looking like clean wort, it just tends to stop up the bag faster. My understanding is that head foam is produced by peptide chains (basically very small proteins) while coagulated trub is much larger, so I don't think you lose anything desirable through this.

I haven't tried it at bottling, but 5 microns is supposedly too big for intentional filtering of yeast--whether that means it leaves enough yeast to carb remains to be seen, but I am optimistic and plan to filter at leat the last part of the wort after secondary. It won't eliminate final sediment (from carbing yeast) but it may reduce off flavors and haze from any fallout in secondary.

 

[Kahless]

$7, 2-3 beers each time, not too much work... sounding better, I'm going to add such a filter to my wishlist, cheers