BrewBag in MT - 10% Efficiency loss

[boicutt]

So, been hating my False bottom for a while in my MT. I saw Brulosopher using the BrewBag in his MT and thought it was a good idea to make the switch. Makes it super easy to lauter and stuck sparges are gone.

Problem is, I've used it for 2 brews now, literally NOTHING has changed in my process except for the bag. I crush my own, and that hasn't changed either. I'm getting a 10%+ efficiency loss on both past brews done with the bag. I can usually figure out what I'm doing wrong but I can't see how replacing a FB with a bag can actually give me that much loss.

Help?

 

[Bobby_M]

Are you trying to sparge? If so, what method? If you fly sparge with a bag, it's not going to be as efficient as a false bottom.

 

[boicutt]

Are you trying to sparge? If so, what method? If you fly sparge with a bag, it's not going to be as efficient as a false bottom.

Batch sparge.

 

[pdxal]

Are you squeezing the bag when done with the batch sparge? That is part of what gives BIABers high efficiency, along with a sparge. You can also tighten the gap on your mill to increase efficiency with no fear of stuck sparges.
What efficiency did you get on these 2 brews?

 

[Kharnynb]

good fine crush helps, also let the bag drain well.

 

[boicutt]

Are you squeezing the bag when done with the batch sparge? That is part of what gives BIABers high efficiency, along with a sparge. You can also tighten the gap on your mill to increase efficiency with no fear of stuck sparges.
What efficiency did you get on these 2 brews?

I do, but not intensely, but that shouldn't change anything for the moment, I only replaced the false bottom by the bag. The process hasn't changed, the crush hasn't changed. Before I start getting more efficiency out of it I'd like to solve my problem and get back to where I was.

It was my intention to tighten the gap eventually.

 

[Hello]

You definitely need a finer crush. That is exactly what I experienced and didn't bother to squeeze harder or anything, I went right to the crush. I actually double crush now so I don't have to adjust my mill just in case I don't want to use the bag, but I'm considering just adjusting it since I realize I probably won't ditch the bag anytime soon.

You can do that or you can account for the efficiency loss with additional grain. I vote adjust your crush, it's technically cheaper. When I do no-sparge, I keep the fine crush but I also account for the loss with additional grain. Normally I am batch sparging.

 

[boicutt]

You definitely need a finer crush. That is exactly what I experienced and didn't bother to squeeze harder or anything, I went right to the crush. I actually double crush now so I don't have to adjust my mill just in case I don't want to use the bag, but I'm considering just adjusting it since I realize I probably won't ditch the bag anytime soon.

You can do that or you can account for the efficiency loss with additional grain. I vote adjust your crush, it's technically cheaper. When I do no-sparge, I keep the fine crush but I also account for the loss with additional grain. Normally I am batch sparging.

I understand this. I'm just trying to figure out what's different in having a bag or a false bottom in my round MT with batch sparge besides the ease of lautering. In what way could this give me less efficiency. I'm crushing the same crush, stirring the same way, temps nailed the same way lautering the same way...etc. I was getting about 78-80% efficiency before. Lost 10% and 8% in past two brews with the bag.

 

[blizz81]

I don't really know what to tell you, but I'll say in my case (RIMS, bottom-draining keggle mash tun, Jaybird false bottom, added a BIAB bag after having difficulties with a few beers re: recirc / drain), we haven't really had any problems hitting our volumes or efficiency numbers after adding the bag.


I would think if it was an issue with squeezing the bag or not letting it drain, you would be a bit low on volume as well. On our brews, after collecting runoffs as normal, I'll let the grist sit for a bit while we reach a rolling boil that we can step away from, and then go back and open the valve up again and collect what's left...usually less than half a pitcher. Sometimes we've let it sit a bit longer and gotten a bit more than that. We've done this before the bag and I wouldn't say this volume changes any, either, and the remaining grist itself hasn't been any different bag vs. no bag - sure, they're both a bit wet still, but no standing liquid to be pushed out or anything.


We generally mash at a 1.25qt/lb ratio + an extra 0.875gal (volume under our false bottom, which I still use, more as a "grant" now than anything), which effectively makes things a bit thinner than 1.25qt/lb, and we recirc (both mash and batch sparge), and bottom-drain...also we crush pretty aggressively at 0.028" and condition our grain....not sure if any of these might make any sort of efficiency / extraction sense vs. your process.