Increasing BIAB efficiency.

[Lord Raja Goomba I]

Excellent post Liam.

For the record, when I was BIABing using the nick JD method, I did a sort of batch sparge thing, whereby I'd stick the drained bag in a colander/pasta pot over a 9L pot (or my 2nd Big W pot), and run boiled kettle water over it a few times, stirring the resultant (2nd) mash. My kettle at the time maxed at 81 degrees (current does 80 degrees, which I measured again three days ago).

Hitting high 70s/low 80s every time.

And I avoided the burnt hands from squeezing.

 

[fletcher]

I haven't tasted or seen the affects of tannins so cant comment personally. A quick Google though gets plenty of hits.
This was one article from beersmith with an associated reply -

"I’d add that even if your temps and pH are in line, grist crush and wort clarity also impact tannin extraction. If you’re getting shredded husk material, you’re more likely to extract excessive tannins. If you get a lot of those grain material into the boil kettle, you can extract excessive tannins that way too. I had a run of about 7 very astringent beers I traced back to shredded husks and poor lautering."


http://beersmith.com/blog/2012/06/19/phenolics-and-tannins-in-home-brewed-beer/

But ultimately its up to you how you mill.

I was just pointing out the fact it is not considered best practice and can cause issues.

cheers mate. at this stage, i haven't honestly noticed a difference. i would like to perhaps give the same batch, one with flour and one without, to an experienced judge or taster and really see if they can find a difference. would be great to find out. i appreciate it's not best practice. the main reason i began grinding to flour was because of Nick JD's method and that i'd read it could be done. it gave some amazing beers and i had a cheap crusher at home so didn't need to fork out $200+ for a mill. i can certainly say that now with access to a mill i use it. not largely because it's considered best practice, but because it's a **** load faster than using my mini coffee grinder.

looking at your quote though, it seems to be talking about the grain material in the kettle. with BIAB, none of this grain material is (or should be) in the kettle after the bag is hoisted. it then goes on to talk about lautering; mostly done with multi-vessel systems, not BIAB. perhaps it's been noticed more with this latter aspect of poor lautering. having a whole chunk of grain/husks in the boil and not specifically BIAB.

 

[bundy]

looking at your quote though, it seems to be talking about the grain material in the kettle. with BIAB, none of this grain material is (or should be) in the kettle after the bag is hoisted. it then goes on to talk about lautering; mostly done with multi-vessel systems, not BIAB. perhaps it's been noticed more with this latter aspect of poor lautering. having a whole chunk of grain/husks in the boil and not specifically BIAB.

The grain material or husk you talk about is definitely in touch with water during the Mash so be it 3V or BIAB the concerns are the same with tannins leaching from the husk into your Liquor / Wort from too fine a crush. Just with 3V it would also cause other issues with a stuck sparge more likley.

I agree the post also states you can get tannins if you heat or boil your Husk as that practice will also leach tannins (Hence the need to limit any Mash-out to below 78 degrees as that is the critical temp where tannins will also leach out)

So the comment describes 2 scenarios on how tannins can leach into your beer. 1 - Too fine a crush and 2 excessive temp on your grain.

Bottom line though if its not causing you problems that's good, but I think it fair to point out to others its not best practice.