Cedar Rapids Brewing Society

I tried the boil in a bag system from Northern Brewer this weekend. The target O.G was 1060. I ended up at 1042. I used the boil kettle as the mash tun, and the only thing I can think is that the lid wasn't sealed properly since the mesh bag stuck out a little. Any ideas?

Stats:

Mash in: 160

Sacch rest: 152 for 75 minutes. When I took the temp after the 75 minutes, it was down to 144.

Mash out: 168 for 10 minutes.

Boil for 60 minutes. Cooled with wort chiller.

Did you wash [sparge] the grains? With a 5 gallon batch I usually try to shoot for 6.5 gallons preboil. last time I had a couple gallons in another pot/cooler with warm water and transferred the bag and stir up.

I used to boil ~4 gallons in my 5 gallon pot and another 1.5 to 2 gallons in another pot that I used to top up the fermenter or the boil kettle. However this adds an extra calculation when calculating IBU's..... if a couple IBU's matters that much anyway...

That may have been my issue...I followed the directions from Northern Brewer. I was wondering when to sparge, and the instructions didn't mention it. Thought maybe it was something you skipped for this BIAB approach.

Looking at one of their recipes (Jake's CDA), they must be calculating total efficiency at 70%. From my experience and reading forum posts by others, that's really high for BIAB. As you've seen, you drop a lot of efficiency. I typically got around 60-63%, and that was with a sparge (I poured hot water over the bag, which I had in a colander). I've seen many people state they get as low as 50%, which is what it looks like you got.

I'd encourage you to call NB and ask them about it. It would be worth knowing what their response is.


On 01/27/2013 04:04 PM, Sully11 wrote:

I tried the boil in a bag system from Northern Brewer this weekend. The target O.G was 1060. I ended up at 1042. I used the boil kettle as the mash tun, and the only thing I can think is that the lid wasn't sealed properly since the mesh bag stuck out a little. Any ideas?

Stats:

Mash in: 160

Sacch rest: 152 for 75 minutes. When I took the temp after the 75 minutes, it was down to 144.

Mash out: 168 for 10 minutes.

Boil for 60 minutes. Cooled with wort chiller.

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I think I will give them a call. Jake's CDA is what I tried. So far, not really impressed with the BIAB.

Doing the sparge is key. I am certain that was why your gravity was so low. I started with BIAB. I would take a scoop of the water/wort I had been mashing in and pour it back over the grains several times. You do this once you have mashed out at 168F. This rinses more sugars from the grain in to your brew pot. Then I would add my extract, any water additions, and boil. Made some award winning beers that way including my first best of show win with a Scotch Ale in 2004.

The guy from Northern Brewer said the same thing about sparging. I think I'm going to try again with this batch. It doesn't appear to be fermenting that well either.

Is it ok to add water if I don't wind up with 3 gallons at the end of the boil?