BIAB Efficiency

I brewed my first 3 gallon BIAB yesterday (had to use a cheap bag but just ordered a new one from wilserbrewer). Anyway, my efficiency ended up at about 68%-69%. I see others talking about much higher efficiency. Are these fish stories or are others regularly getting much higher.

If possible, how do I improve my efficiency?

I regularly get about 85% with double milling my grains. You could try this as with BIAB you can mill your grains much more fine without problems

I usually get around 73-75%

The low efficiency myth of BIAB is widely reported. When I started BIAB I too was under this false impression.

With refinement of the process consistent efficiencies in excess of 80% are readily obtained.

My process is outlined in detail in the links below my signature. Might be of use in answering your suspicions of fishy tales.

kevinb said:

I brewed my first 3 gallon BIAB yesterday (had to use a cheap bag but just ordered a new one from wilserbrewer). Anyway, my efficiency ended up at about 68%-69%. I see others talking about much higher efficiency. Are these fish stories or are others regularly getting much higher.

If possible, how do I improve my efficiency?

Click to expand...

First, to make sure we're all on the same page, I'll assume you're talking brew house efficiency. 68% is a very respectable efficiency to achieve your first go round. And I would wager it will get higher as you fine tune your system.

Because your efficiency isn't bad to begin with, I'd recommend you focus on consistency for these first few batches. Sure there's probably some low hanging fruit you can get, like a finer crush. Those will be easy. But don't get hung up on chasing that efficiency number.

Also, I like talking mash efficiency rather than brew house. Mash efficiency tells the story of how good you are at extracting the sugars from the grain. Brew house efficiency muddles everything by involving a side plot of how good you are at transferring wort to your fermenter (edit #2).


Edit: forgot to mention, those aren't fish tails. I get 80-85% on beers up to ~8-9% ABV, and got 73% on the 10.8% barley wine I just did.

TexasWine said:

Also, I like talking mash efficiency rather than brew house. Mash efficiency tells the story of how good you are at extracting the sugars from the grain. Brew house efficiency muddles everything by involving a side plot of how good you are at transferring wort to your kettle.

Click to expand...

+1^^^
Agreed. I think both numbers a very useful in not only highlighting areas where a process can be improved, but in planning future brews.

kevinb said:

I brewed my first 3 gallon BIAB yesterday (had to use a cheap bag but just ordered a new one from wilserbrewer). Anyway, my efficiency ended up at about 68%-69%. I see others talking about much higher efficiency. Are these fish stories or are others regularly getting much higher.

If possible, how do I improve my efficiency?

Click to expand...

1. Crush the @!#$% out of the grains. BIAB lets you perform a much tighter crush than a traditional mash because you can never get a stuck sparge.

2. I use gravity to suspend the bag after I pull it out, you will get a bunch of running that way. To get better efficiency I do a dunk sparge. I mash with around 70% of the total water and I let the bag drain for 5 minutes while the wort heats up, then lower the bag into a second pot with the remaining 30% of the water. Stir it up, move the grain around, for a minute, then raise the bag.
Let it drip for 5 minutes and pour all of the second runnings into the kettle.

I my experience BIAB can be less efficient with 20+ pounds of grain without the dunk sparge as too much sugar remains trapped in the liquid in the bag.
The quick dunk sparge always puts me above 80%

I did a 2.5 gallon batch yesterday. I get around 80% - 84% every time. From all my research and now practice, a fine crush is the key.

TexasWine said:

First, to make sure we're all on the same page, I'll assume you're talking brew house efficiency. 68% is a very respectable efficiency to achieve your first go round. And I would wager it will get higher as you fine tune your system.

Because your efficiency isn't bad to begin with, I'd recommend you focus on consistency for these first few batches. Sure there's probably some low hanging fruit you can get, like a finer crush. Those will be easy. But don't get hung up on chasing that efficiency number.

Also, I like talking mash efficiency rather than brew house. Mash efficiency tells the story of how good you are at extracting the sugars from the grain. Brew house efficiency muddles everything by involving a side plot of how good you are at transferring wort to your fermenter (edit #2).


Edit: forgot to mention, those aren't fish tails. I get 80-85% on beers up to ~8-9% ABV, and got 73% on the 10.8% barley wine I just did.

Click to expand...

What is the difference between mash efficiency and brew house efficiency? I used the calculator on https://brewgr.com/homebrew-recipe-calculator to backcalculate my "efficiency".

I'm also in the mid to high 80s for mash efficiency (overall eff usually ends up around 75%).

I echo crushing the hell out of your grains if you have a mill. I also recirculate with an electric setup which may help. Don't think this is necessary as others get good eff without this.

Maybe a better crush is something quick and dirty to try out.

kevinb said:

What is the difference between mash efficiency and brew house efficiency? I used the calculator on https://brewgr.com/homebrew-recipe-calculator to backcalculate my "efficiency".

Click to expand...

I like this chart for an explanation of efficiency. I guess they don't use the term "mash efficiency", but instead use conversion efficiency.

http://www.brewersfriend.com/brewing-efficiency-chart/

TexasWine said:

I like this chart for an explanation of efficiency. I guess they don't use the term "mash efficiency", but instead use conversion efficiency.

http://www.brewersfriend.com/brewing-efficiency-chart/

Click to expand...

Thanks for the visual, I was talking about brew house efficiency.

TexasWine said:

I like this chart for an explanation of efficiency. I guess they don't use the term "mash efficiency", but instead use conversion efficiency.

http://www.brewersfriend.com/brewing-efficiency-chart/

Click to expand...

What I believe most people use for efficiency is the percentage of potential sugars that make it (out of the mash and) into the boil pot. Brewersfriend calls this "Pre-Boil Efficiency." I think many people refer to this as "Mash Efficiency."

"Conversion Efficiency" is what percentage of the potential sugar actually got created during the mash.
Conversion Efficiency should always be greater than 98%. If Conversion Efficiency is low, it can be due to the following things:

• Mash temp too high. The amylase enzymes get denatured before starch to sugar conversion is complete.
• Mash temp too low. Conversion reactions happen slower at lower temperatures, and not enough time was allowed for conversion to complete. Or, temp too low for significant conversion to even occur.
• Mash time too short. Not enough time allowed for conversion reactions to complete.
• Crush too coarse. Larger grain particles take longer to convert than smaller particles (all else being equal). Mash time and crush size interact very strongly.
• pH too high or too low. Slows down conversion reactions, and may limit completion if far enough off.
• Dough balls. Dry clumps of grain don't participate in the mash, so no sugar gets extracted from them.

For most people having Conversion Efficiency issues, it's the crush too coarse for the mash time that is the root cause. I give an explanation of how to calculate conversion efficiency here (personally I find Kai's explanation harder to follow, but ymmv.)

"Lauter Efficiency" is the percentage of sugars actually created during the mash that make it into the boil kettle.
Lauter Efficiency can be impacted by:

• Undrainable volume in the mash tun (dead volume). Some of the sugar always remains in the dead volume.
• Grain absorption. The more wort retained in the grain, the more sugar is retained.
• Insufficient agitation during mash or prior to run off. If the concentration of sugar in the free wort and wort held in the grain particles isn't equal before run off, less sugar is obtained during run off.

"Pre-Boil (or Mash) Efficiency" is the percentage of potential sugars that actually make it into the boil kettle.

If your Pre-Boil (Mash) Efficiency is low, then you should determine your Conversion Efficiency. If your Conversion Efficiency is low, then you need to address the items above that can reduce Conversion Efficiency. If your Conversion Efficiency is good, then you need to address the items above that can reduce Lauter Efficiency.

Brew on