New to BIAB, Feedback Please

[hellesyeah]

After many extract batches (with steeping grains) I made the wholesale move to BIAB two brews ago.

Brew one was an ESB with pre-milled grains and got an eff of 70%. I used Wyeast 1968 and the starter I made looked funky like chunks of yeast that never did smooth out. The post fermentation yeast cake looked weird too so I didn't try to save any for a later batch but all seemed ok anyway. Started at 1.057 and finished at 1.014. What was wrong with my yeast?

In the meantime I got a Cereal Killer Mill and ground my own grains for a Wit Beer. Not exactly sure what to do with the gap (I used a corded drill slowly grinding if that matters) so I set the gap to right at .030. I ran my numbers and got 76.3% so I saw an immediate improvement. My grind looked good with low powder but I noted some husks that looked like they shredded off. Not sure why it did this but I didn't notice this in the milled grains from the LHBS. Is my grind gap causing the husks to shred off? Is this going to mess up my beer? Thanks all!

 

[chickypad]

Doesn't sound like anything was wrong with your yeast. Some of those English strains like 002, 1968 always look chunky like that in the starter. You can go pretty fine with BIAB so I wouldn't worry about that. With the bag you don't get a stuck mash.

 

[bruhaha]

Some high flocculating yeasts behave as you as describing. Good thing is you'll have a nicely clear beer.

Google up "grain conditioning" where brewers spritz a small amount of water on unmilled grains to moisten (lightly) the husks, however I fear the moisture will rust my non-stainless rollers. I used to think that shredded husks caused astringency, but I am not sure it really does. I BIAB too and see shredded husks but never had an astringency taste issue I was aware of. You can grind tight for BIAB since sparge issues are typically not a problem.

 

[RM-MN]

When you use a conventional mash tun the husks help form the filter for when you drain the tun. With BIAB the bag takes the place of the husks so you can shred them all you like. Astringency is caused by extracting tannins from the husks but that requires a pH of over 6.0 and temperature over 170. About the only way to get that combination is by fly sparging with hot water. You won't be fly sparging so you don't need to worry about that. When I set up my Corona mill I left no gap at all. When it has no grain in it the mill sounds terrible like it will come apart but it mills the grain fine and my efficiency exceeds 85%. Go ahead and tighten your mill. If you decide you don't like the results you can easily adjust it differently. Be aware that you will need to adjust your base malt for the higher expected efficiency or be prepared for a higher alcohol content beer. My first was expected to be about 5% but came out at 7%.