and another BIAB Efficiency thread...

I brewed up a Hopslam clone yesterday and for the second** time now I'm a bit disappointed with my low brewhouse efficiency (62.27% per brewersfriend.com)

Here's the recipe: https://www.homebrewtalk.com/f69/all-grain-hopslam-clone-219599/

I mashed with 8.5 gallons of Deer Park water (my water's heavily chlorinated) and a total of 20.29 lbs of grain (Strike water (8.5) = 5.5g + (20.29 x .074) + 1g + .5g). I calculated that out to a 1.68 qts/lbs ratio, which seems thin enough. [It also helps to note that this water/grain combo is the absolute max my 11g kettle can handle.]

I mashed for 60 minutes @ 150 degrees (strike temp = 163), stirring every 15 minutes. The temperature stayed constant. Following that, I brought her up to 170 and rested for 10 mins (mash out). I drained my bag thoroughly and hit my pre-boil target spot on (7 gallons).

So my question is, should I be concerned with this low efficiency or should I RDWHAHB? I know BIAB efficiency drops with larger grain bills, and this grain bill was my largest to date.

Outside of checking the pH of Deer Park water, I don't know what in the process I should change. Looking for advice/constructive criticism. I'm pretty new to brewing and BIAB, this being my 5th attempt at BIAB and 7th brew overall.

**I did not calculate efficiency for my first 3 BIAB's. My last BIAB was Denny Conn's Old Stoner, and I hit 63-64%.

Water Chemistry can be an issue, if it's a hard spring water you might have pH issues that can affect efficiency.

Crush could be the single largest culprit, are you double-milling the grains on a very fine setting?

Huge grain bills like this also tend to have a lower efficiency, especially if you're no-sparge BIABing.

What was the OG of your beer at the end of the boil? Did you get near 1.098 as the recipe indicates? If yes, then I wouldn't worry too much about your efficiency at this point. With such a large amount of grain in the kettle you're bound to get reduced efficiency if you were maxed out on kettle space. It's harder to stir the mash when it's so jam packed in the kettle. I know because I've brewed this exact same recipe using a 10-gallon kettle and it was almost impossible to stir well. Big beers like this is one of the reasons why I'm going to get a 15 or 20 gallon kettle in the future.

Crushing the grain really fine, or double crushing, should help improve efficiency next time.

I BIAB and usually get 80% efficiency.

I grind my grain at .027" on my mill and use an automotive feeler gauge to set the gap. If you are milling at your homebrew shop, they probably won't let you re-set the roller gap, so you can run it through twice if you want.

I dont stir much during the mash, only really well at the beginning and end, so I don't think that is the culprit for you.

I noticed when mashing out that I would raise my wort temp to 17+ degrees and then lower the bag back in and the wort temp would then be around 160. So I usually raise the mash out temp to an even higher temp to account for this. I always double check after dropping the bag back in and stirring and adjust if necessary. I know some people don't think this step improves efficiency much in BIAB, but I do it and I feel like it does. I haven't proven it empirically, though.

If you are fully converting your grain, I would not think the water is the problem. If there is something so wrong with the water chemistry, then your conversion will be effected and you will be able to tell with a iodine test.

I should have looked at the recipe... 1.098 is a big beer and I don't think getting a lower efficiency should worry you too much. One thing you could try when doing such a big beer is to do a dunk sparge, where you pull a couple gallons of your mash water and heat it so that when you are done with your mash, you pull the bag and dunk it in the two or three gallons you set aside, stir well drain and then pitch this in with the rest. It is supposed to help get better efficiency because you are rinsing the grain with water that doesn't yet have a bunch of sugars dissolved in it... Just a thought for something to try.

Thanks for the responses so far, guys. Yes, I double crushed my grain at the local homebrew shop. I seem to get a good crush, all husks removed and a granulate like flour.

I'm using a homemade voile bag that is plenty large. Despite the kettle being maxed out, I was able to stir and eliminate any dough balls. Just made a little bit of a mess.

While I was bringing the mash up to 170 degree, I tried gently 'rolling' or rocking the bag within the kettle to move the grain around a bit. I did not notice any improvement in my efficiency with the mash out, when compared to the barleywine I brewed three weeks ago w/o a mash out.

To Seven -- Thanks for letting me know the link didn't work. I'll try to fix that. I used the recipe based on your recommendation in the BIAB sticky you created. I adjusted my final gravity by adding two pounds of DME, using the calculations found in Ray Daniel's 'Designing Great Beers', 539GU (desired) - 448GU (actual) = 91GU; 91/45 (the GU's of DME) = 2.02 lbs DME needed. I hit my target gravity pretty much spot on at 1.096 (1.098 was ideal, per schweaty's recipe). I agree a 15-20g kettle would be nice for these big beers!

She's fermenting away just fine. I learned the hard way from the barleywine that these big beers need a blow-off tube.

ElDuderino said:

I should have looked at the recipe... 1.098 is a big beer and I don't think getting a lower efficiency should worry you too much. One thing you could try when doing such a big beer is to do a dunk sparge, where you pull a couple gallons of your mash water and heat it so that when you are done with your mash, you pull the bag and dunk it in the two or three gallons you set aside, stir well drain and then pitch this in with the rest. It is supposed to help get better efficiency because you are rinsing the grain with water that doesn't yet have a bunch of sugars dissolved in it... Just a thought for something to try.

Click to expand...

I'd like to give this a try, but my only other kettle is 5.5g. With a grain bill of 20.29lbs, already 'soaked', I don't know if a 5.5 gallon kettle would be big enough to handle the wet grain plus another 2-3 gallons of water. How could I figure that out (rather than trial and messy, messy ERROR)?

Riseabovebb said:

I hit my target gravity pretty much spot on at 1.096 (1.098 was ideal, per schweaty's recipe). I agree a 15-20g kettle would be nice for these big beers!

She's fermenting away just fine. I learned the hard way from the barleywine that these big beers need a blow-off tube.

Click to expand...

You should be fine since you hit your target post-boil gravity almost spot on.

It's almost time for me to brew this one again. Be sure to let us know how yours turns out!

My first two BIAB batches hit 62% and 68% efficiency respectively. The third batch that I just brewed on Saturday hit about 85%. The only thing I changed was better insulation during the mash and a better controlled mash out.

Hopslam was my second all grain batch and I was really excited. The first batch was a Centennial IPA that hit all my targets (OG and FG) without a hitch.

I mashed about 18.5 ibs of grain at about 152 (too high) and when it came to batch sparging, beersmith said I needed only 2.5 gallons. Is that right? Anyway, my OG came in at 1.065, or roughly 40% efficiency. What did I do wrong? My pre-boil volume was only 5.5 gallons, so something isn't adding up.