maltoftheearth

Recipes 

I brewed two consecutive BIAB beers and pitched off the same yeast cake (lager yeasts) for both. I was looking at the carboy the other day and noticed multiple layers of tan colored trub in the bottom with thin layers of white trub in-between. It is my understanding that this white layer is yeast.

This made me wonder whether BIAB is a method that may lend itself to stuck fermentation. Specifically, given the amount of particulate matter dropping out of suspension I wonder if this can either:

1. Drop yeast out of suspension
2. Coat yeast at the bottom of the carboy in such a way as to impede their ability to access sugar

I have not had a stuck fermentation yet with BIAB but I noticed by searching that others on this board have. Just a thought, I am new to brewing so I would be happy to hear whether either of these thoughts are valid or not and why. Thanks.

__________________
Long range forecast:

5G Carboy Primary (1): Belgo Clone
5G Carboy Primary (2): Cream Ale
2.5G Carboy Primary: Empty

Keg 1: Casper the Friendly Kolsch
Keg 2: Salt n' Peppa IPA
Keg 3: Slip One to the Porter
Keg 4: Russian Oligarch Stout
Keg 5: Jacker the Rye-per IPA
Keg 6: California Commoner

paraordnance

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I nevr had problems with my BIAB lagers. I must have done 5-6 of them this year, fermenting Oktoberfest as we speak

tennesseean_87

Recipes 

I have heard that excessive trub is a result of BIAB method. Are you asking if this buries the yeast to the point where pitching on a yeast cake will not give enough access of the yeast to the new wort? Would removing and quickly washing the yeast to separate the trub matter prevent this?

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#8 Corks in Belgian Bottles Hold Carbonation
Drinking: Graham's Cider, Sour mash Red, Rochefort 8 clone, Yeti Imp Stout clone, Brown Sugar Spiced Cider, Split batch IPA/SBitter, Oatmeal Brown Ale, Belgian Pale Ale, Oatmeal Dry Stout
Bottle conditioning: Graham's Cran-Apple Oaked Cider, Raspberry Apfelwein, Split batch Tripel, Split Batch Pilsener
Fermenter: Graham's Cran-Blue-Pom-Apple Cider
On Deck: Gun Stock Old Ale, BC Haus Pale (half nugget, half columbus), Berliner Weisse

maltoftheearth

Recipes 

Yes, that was basically my question. I am hesitant to go through washing as I was under the impression that when repitching on the same cake we should do that as soon as possible and avoid too much exposure to oxygen.

__________________
Long range forecast:

5G Carboy Primary (1): Belgo Clone
5G Carboy Primary (2): Cream Ale
2.5G Carboy Primary: Empty

Keg 1: Casper the Friendly Kolsch
Keg 2: Salt n' Peppa IPA
Keg 3: Slip One to the Porter
Keg 4: Russian Oligarch Stout
Keg 5: Jacker the Rye-per IPA
Keg 6: California Commoner

dcp27

Recipes 

in general unless the next beer is significantly bigger, you shouldn't be pitching directly onto a full cake. its not beneficial and you're over-pitching. i'd wash the yeast first.
http://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

not sure where you heard that, but IME that hasn't been the case and doesnt make any sense to me.

tennesseean_87

Recipes 

In DeathBrewer's BIAB stovetop thread a few people mentioned it. They said it was due to not using the grain-bed as a filter because you just pull the bag out instead of running the water out of the bottom. I've not done it before, but am hoping to try it.

__________________
#8 Corks in Belgian Bottles Hold Carbonation
Drinking: Graham's Cider, Sour mash Red, Rochefort 8 clone, Yeti Imp Stout clone, Brown Sugar Spiced Cider, Split batch IPA/SBitter, Oatmeal Brown Ale, Belgian Pale Ale, Oatmeal Dry Stout
Bottle conditioning: Graham's Cran-Apple Oaked Cider, Raspberry Apfelwein, Split batch Tripel, Split Batch Pilsener
Fermenter: Graham's Cran-Blue-Pom-Apple Cider
On Deck: Gun Stock Old Ale, BC Haus Pale (half nugget, half columbus), Berliner Weisse

terrapinj

Recipes 

that would result in grain particles entering the BK pre boil - wouldn't have any effect on the break material after the boil

I use the same paint strainer bag for BIAb and to filter after the boil - i haven't noticed any negative side effects for poor yeast performance or off flavors

in fact some break material is beneficial for healthy fermentation

seabass07

Recipes 

I don't see how this could impede the yeast. For one the trub will fall out first when everything get's stirred up. If you decide to pitch on a cake, just swirl up the fermenter. The yeast will become suspended in the wort and the other crap will fall out. It is overpitching though and only worth it if you are making a massive beer.

There's no issue with washing yeast. You can get several batches out of a single yeast cake.

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Fermenter 1: Beer
Fermenter 2: Beer

dcp27

Recipes 

+1

I actually run the water out of the bottom of mine so I guess I wouldn't notice that anyway.

solbes

Recipes 

I've done 4 BIAB batches now and have had great attenuation every time. I did pitch onto 1/3 of a cake of Patersbier for my 1.080 Carmelite Tripel. The other 2/3 I removed and washed to save for a Dubbel later this year. With the Tripel I had active fermentation in 2 hours and it blew the airlock about 12 hours later (with plenty of Fermcap-S foam control). So I don't think there are any worries of the trub hiding the yeast.

I have noticed a pretty good amount of trub with BIAB, but I've never done a traditional AG brew to compare to. I don't' the trub affects anything at all, so I don't worry about it. It gets left behind when I rack out of primary.

__________________
Primary #1: Empty #2: Empty
Secondary #1: Belgian Golden Strong #2: Dark Belgian Strong #3: Barolo Wine #4: Framboise Lambic
Kegged: RedHook ESB clone, Fat Tire Amber
Bottles: Surly Furious clone, Kicked by a Moose Scotch Ale, Apfelwein, Russian Imperial Stout, Trappist Dubbel, Carmelite Tripel, Pinot Noir, Rhubarb Wine
On Deck: Kölsch IV, Altbier II