First BIAB session, comments and thoughts welcome

[PhinneyWoodBrews]

Howdy, ya'll. To start, let me thank all who contribute to the knowledge base on this forum. I've spent many hours researching and reading the information you've shared. After 3+ years of counter-top extract and partial-mash brewing, I decided to step up to all-grain with BIAB. I have a 20 gallon megapot that I mash on a 75,000 btu propane burner. I did my first brew yesterday, and wanted to post my results and my thoughts for comment. The brew was a 5 gallon batch, as I wanted to dial in the process before doing 10+ gallon brews.

I heated 7.5 gallons of strike water to 165 degrees and mashed in the following grist:

11# 2-Row
1#Crystal 80
1# German Pils
.75#Munich
.5#Caravienne
.5#Melanoiden

Total grain bill weight: 14.75 lbs. Crushed on 'fine' setting at LHBS.

My brew buddy poured the grain in slowly while I stirred. Hit the mash-temp of 156 spot on(thank you, brewsmith!).

Mash was stirred and checked for temp at 30 minutes and at 45, and at mash out(pulling the bag out). Mash temp dropped to 154 after 30 minutes, and was at 150 at the end. Kettle was wrapped in a towel, heavy parka, and a sleeping bag, but it was pretty cold yesterday(about 45f).

After letting the bag drip into the kettle and lightly squeezed, the pre-boil volume was 6.5 gallons, and the gravity was 1.052(beer smith estimated should be 1.067)

We did a sixty minute boil.

At flame-out the volume was about 5.5 gallons(not accounting for shrinkage).

OG was at 1.062, beersmith had predicted 1.077 based on 72% efficiency. If I'm reading their mash calc properly, it looks like I got about 63% eff.

I also only got 4.12 gallons into the fermentor, as the large hop bill soaked up a good deal of wort. All in all, I think it went pretty well. For my first BIAB, I was expecting about that efficiency, and was actually aiming for around 1.060 OG.

I have some ideas for increasing my eff next batch, let me know what you think:
1. Finer crush(double pass through mill)
2. More frequent stirring
3. Reserve 1.5 gallons for sparging bag.
4. Recirculate wort during mash to maintain temps-also wheel the kettle inside to reduce heat loss.
5. Longer mash

I'd greatly appreciate your feedback on my process and possible improvements. Thanks!

 

[h22lude]

Finer crush would help with efficiency but not if you recirculate. Recirculating biab should us regular crush.

 

[doug293cz]

Finer crush would help with efficiency but not if you recirculate. Recirculating biab should us regular crush.

Why?

Brew on

 

[BlueHouseBrewhaus]

Double crush and reserve about 2 gal for a very slow (30 min) trickle sparge through the raised grain bag (pulley helps). These two things took my efficiency from 65% to 80%. Unbeknownst to me, my LHBS replaced their grain mill last month. I did my usual double crush and got 86%!

 

[soccerdad]

And don't be afraid to mash for more than 60

 

[paperairplane]

Or...... accept your efficiency, adjust beersmith and don't worry about all that other ****.

I BIAB and get a pretty consistent 65%. I use a Corona and grind very fine.

Play around in Beersmith and see what the actual grain difference is to hit a given gravity at different efficiencies.

It's just easier to add a little extra grain - BIAB, at least to me, is about having a nice simple day.

 

[BlueHouseBrewhaus]

And don't be afraid to mash for more than 60

Uh-oh! The mash revolutionaries will be here soon to talk about 10 min mashes! Don't mess with them

All kidding aside, paperairplane is right. Consistency is much more important than efficiency. I'll take a consistent 65% over a fluctuating 75% - 85% any day.

 

[wysiwyg]

And don't be afraid to mash for more than 60

THIS! I have an electric BIAB rig and I do a 90 minute mash and a 10 minute mashout which is nearly the same grain/water contact time as a 60 minute mash with a ~30 minute sparge. Then I squeeze the snot of out my bag to get as much of that sugary goodness into my pot.

I do a 60 minute boil and use a hopsock to keep all the hop junk out of my plate chiller, then squeeze the snot out of the hopsock too.

I've made five different beers this way, and while I always add a bit more base grain to compensate for the reported efficiency loss of BIAB, I always exceed the recipes numbers. I bet I'd hit them dead on if I left the grain bill alone.

 

[RM-MN]

Why?

Brew on

Because when you recirculate the finer milled grains tend to plug up the bag.

 

[TexasWine]

I wouldn't recirculate. Pumping the wort around in a circle will only increase your heat loss, and without an automated system it's gonna be a pain in the rear to maintain temps. Of course I'm assuming you don't have an automated system. If so, it's a great idea to recirculate.

 

[h22lude]

Because when you recirculate the finer milled grains tend to plug up the bag.

This. Plus you are constantly moving wort around which helps circulate the sugars. Just think, why do a lot of people stir 2 or 3 times during their mash? This is the same thing only you are doing it for all 60 minutes. Better efficiency.

I wouldn't recirculate. Pumping the wort around in a circle will only increase your heat loss, and without an automated system it's gonna be a pain in the rear to maintain temps. Of course I'm assuming you don't have an automated system. If so, it's a great idea to recirculate.

Well I would think any BIAB system can heat the pot when mashing. Not having automation doesn't limit someone from not heating during mash. It will just take more watching over. But I agree, you will definitely need to heat the mash if recirculating

 

[PhinneyWoodBrews]

JohnFocht: Thanks for the input! I built a hop spider, but doing a five gallon test brew, it wouldn't have made much contact from high atop the perch of the 20g kettle. Here's a question: Do you raise the hop bag out at flameout and let the wort in the hops trickle out? I know squeezing hops are a no no. As a former extract brewer limited to topping off with distilled water at the end, I'm used to rinsing the hop bag as I top off. What's your method?

 

[PhinneyWoodBrews]

Well I would think any BIAB system can heat the pot when mashing. Not having automation doesn't limit someone from not heating during mash. It will just take more watching over. But I agree, you will definitely need to heat the mash if recirculating

Yeah, I don't have a pump or a means of externally heating recirculated mash. I know I can adjust heat if the bag is kept clear of the bottom, but that seems like it would involve a lot of finagling with the burner, which would be more of a hassle compared to coming up with a better insulation solution. I plan on constructing a reflectix jacket soon. I'm also thinking that a small batch in a big kettle resulted in the dead space acting like a heat sink more so than it would if I were doing a 10+ gallon brew.

 

[PhinneyWoodBrews]

Thanks for all the feedback, people! I really appreciate it. You guys rock.

 

[PhinneyWoodBrews]

And don't be afraid to mash for more than 60

If I do go for a 90 minute mash, I assume I'll need to be adding heat at certain times to maintain my mash temperature. How often do you find yourself firing up to heat?(or are you fortunate enough to be automated in that regard)

 

[soccerdad]

I pay close attention to temp for 60 minutes and stir and check every 20. Then I let it sit for a while ... I don't measure it to 90 total or any other number. I just tend to other stuff for whatever time it takes.

 

[h22lude]

If I do go for a 90 minute mash, I assume I'll need to be adding heat at certain times to maintain my mash temperature. How often do you find yourself firing up to heat?(or are you fortunate enough to be automated in that regard)

I would do research before doing a 90 minute mash. These aren't typically used for a normal mash temp. It will create a more fermentable beer. I would work on your crush before doing a longer mash. Just my opinion.

 

[soccerdad]

I would do research before doing a 90 minute mash. These aren't typically used for a normal mash temp.

This is true. A typical 60 minute mash is more often followed by an increase in temp, as you sparge for another 10, 15, 20 minutes.

 

[wysiwyg]

JohnFocht: Thanks for the input! I built a hop spider, but doing a five gallon test brew, it wouldn't have made much contact from high atop the perch of the 20g kettle. Here's a question: Do you raise the hop bag out at flameout and let the wort in the hops trickle out? I know squeezing hops are a no no. As a former extract brewer limited to topping off with distilled water at the end, I'm used to rinsing the hop bag as I top off. What's your method?

I use bags from Wilserbags and secure a smaller bag to the side of my kettle with a bulldog clip so it hangs plenty far into the boil without touching my coil. Why are squeezing hops a no-no? Is there such a thing as hoppy-ungoodness? The way I look at it, squeezing the hopsock is no different than throwing the hops right into the boil and then dumping them into the fermenter. Even with a hopblocker, the hops get 'squeezed' as the wort pushes through it. I squeeze at flameout and sanitize my gloves first. No off-flavors so far, just hoppy goodness.
To address some of the other BIAB issues raised on this thread - I have an electric rig that maintains temp during the 90 min mash. I don't recirc, but I stir well every 20 minutes. I mill my grain twice at the LHBS using whatever setting they have. I don't enter contests yet, but I haven't made a beer I want to spit out, and I get nothing but compliments from the people I give it to.
Someone who's not just guessing can convince me my methods are wrong.
The thing about homebrewing - try it. If you don't like it, try something different. What works for me might not work for you, and vice-versa. In the end, you get beer, and that doesn't suck.

 

[jtratcliff]

for me crush was key to getting efficiencies in the 80s. Double crush at LHBS had me in the 70s but crushing at home with my ugly junk corona mill until almost flour bumped it up into the 80s.

I do a 45-60 minute mash with a 15ish minute mashout/dunk sparge in a separate pot, and squeeze like hell.

I also just clip a large hops bag to the side of the kettle during the boil.

I do direct fire the kettle during the mash if my temps drift too far... I'm stovetop,
so not as powerful as a propane burn, and I stir while heating, but I don't bother to
lift the bag (also a wilserbrewer bag) and so far no scorching.

 

[RM-MN]

I use bags from Wilserbags and secure a smaller bag to the side of my kettle with a bulldog clip so it hangs plenty far into the boil without touching my coil. Why are squeezing hops a no-no? Is there such a thing as hoppy-ungoodness? The way I look at it, squeezing the hopsock is no different than throwing the hops right into the boil and then dumping them into the fermenter. Even with a hopblocker, the hops get 'squeezed' as the wort pushes through it. I squeeze at flameout and sanitize my gloves first. No off-flavors so far, just hoppy goodness.
To address some of the other BIAB issues raised on this thread - I have an electric rig that maintains temp during the 90 min mash. I don't recirc, but I stir well every 20 minutes. I mill my grain twice at the LHBS using whatever setting they have. I don't enter contests yet, but I haven't made a beer I want to spit out, and I get nothing but compliments from the people I give it to.
Someone who's not just guessing can convince me my methods are wrong.
The thing about homebrewing - try it. If you don't like it, try something different. What works for me might not work for you, and vice-versa. In the end, you get beer, and that doesn't suck.

Why do you sanitize your gloves first? At flameout, the wort should be a about 210F. and pasteurization happens within seconds at that temperature.

crushing at home with my ugly junk corona mill until almost flour bumped it up into the 80s.

I do a 45-60 minute mash with a 15ish minute mashout/dunk sparge in a separate pot, and squeeze like hell.

With your grains milled that fine, have you thought about mashing for less time? I suspect that your mash is done within 30 minutes at most and perhaps at 20 minutes. Also, I never do a mashout. When I pull the bag the heat gets turned on and the wort is past mashout temperature in just a few minutes as it is on its way to boil.

 

[Culln5]

Here is a general look at my 75% Efficiency BIAB brew process (10lb grain bill):

• Heat 5.00 gallons of water to strike temperature (temp depends on the body of the beer I'm brewing) and add the bag and grains
• Mash for 1 hour stirring every 10-15 minutes (I've done 30 minute iodine tests and conversion has been complete)
• Hang, drain, and moderately squeeze the bag
• Transfer the mash into the primary bucket (I'm building a brew stand to use another kettle to eliminate this transfer)
• Heat 4.25 gallons of water to 170 and add the bagged grains
• Batch Sparge for 15 minutes (stirring often)
• Hang, drain, and moderately squeeze the bag
• Add the mash volume back to the kettle
• 60 Minute boil

 

[wysiwyg]

Why do you sanitize your gloves first? At flameout, the wort should be a about 210F. and pasteurization happens within seconds at that temperature.

Agreed, probably not needed, but doesn't hurt anything either. Thanks for pointing out a useless step in my process!

 

[nutty_gnome]

I have found that my efficiency with 5.5 gallon BIAB sessions in my 10 gallon pot is strongly correlated with the amount of grain in the recipe. I have now done 4 batches of 'quick beers' that had between 7 and 8 pounds of grain mashed in 7 to 7.5 gallons of water. These are smallish beers (1.040-1.042) and I find that I get about 80% efficiency. At 10 to 13.5 pounds of grain and around 8 gallons of strike water, efficiency drops to around 73-62% depending upon grain weight. Thats what I've found with this process. Even with the efficiency loss, I still like it better that multi-vessel brewing.

 

[jtratcliff]

With your grains milled that fine, have you thought about mashing for less time? I suspect that your mash is done within 30 minutes at most and perhaps at 20 minutes.

Yeah, I've been following the experiments that you and others have been doing with short mash times... I sometimes go for 40 if I know I'm in a hurry. I wouldn't loose to much sleep about going 30. But I'm generally multi-tasking enough with other things, that the whole hour fits into my schedule just fine.

Also, I never do a mashout. When I pull the bag the heat gets turned on and the wort is past mashout temperature in just a few minutes as it is on its way to boil.

I'm not *really* doing a regular mash out, but instead a hot dunk sparge, I guess. I heat my sparge water in a separate pot to 190F or so.

I start firing the main mash tun/ kettle for a couple minutes right before I pull the bag. Before it gets too hot to handle, I pull the bag, squeeze and let it drain a little. I crank up the heat under the kettle to head to the boil, then do the hot dunk sparge (at mashout temps) in the other pot.

 

[marcopolo]

Hey Phinney,

My name is Marco, and I also just did my 1st BIAB today ! I've done several types of brewing since 2008, extract, extract w/ steeping specialty grains, AG single infusion, step mash & decoction - all with an insulated cooler. I've employed the fly-sparging, batch sparging & no sparging techniques as well. I primarily do single infusion and batch sparge, however today I decided to try BIAB.

I used about 17 Lbs grain in hopes of brewing an IPA, however my gravity readings indicate that this one will be more of an APA. My efficiency was pretty poor, but that seems to be common for newbie BIAB brewers. I remember having poor efficiency when I was no-sparging (which is very similar to BIAB).

I totally enjoyed this experience because I mashed in my boil kettle (eliminated a transfer step), I didn't sparge, and I was able to do a direct-fire mash. I mashed in at 60* F and took the mash temp up to 140* F (took about 20 min); I then did a 20 min Beta enzyme rest around 144* F; then went up to 154* F for a 20 min Alpha enzyme rest; I mashed out for 10 min at 159* F. I drained the bag into a pan & then poured that wort into the main wort - trying to minimize intro of O2 into wort (Hot Side Aeration). I did not squeeze the bag because of my fear of extracting tannins from the grain. I proceeded as usual with the boil, etc...

I did stir the wort fairly constantly to avoid scorching. The wort tastes really good even though my efficiency was so poor. My OG was supposed to be 1.088, but it came in at 1.059. I think I may have started with too much water, plus I leave about 2 gal wort & trub in the kettle. I did a 90 min boil.

Overall, I was quite happy with the experience. I'll try this technique again. I've been building a HERMS system over the past couple years just so I can try recirculating the mash & also controlling the temp. I really like BIAB & think this will be my preferred system when doing step mashes. (At least until I get the HERMS up & running). I'm not sure if I will become an exclusive BIAB brewer because I like single infusion and an occasional double decoction. I did however, really enjoy my brewday.

I reckon the truth will be in the finished product. My best beer ever was a no-sparge Brown IPA (Gordon Strong recipe), and that was part of my inspiration to try BIAB.

HAPPY BREWING TO ALL !

 

[PhinneyWoodBrews]

Hi, Marco! Thanks for sharing your experience in such detail. I'm continuing research into improving my BIAB process and I'll share results when I have them. Hoping to brew next weekend. Cheers!

 

[jtratcliff]

I used about 17 Lbs grain


My efficiency was pretty poor, but that seems to be common for newbie BIAB brewers. I remember having poor efficiency when I was no-sparging (which is very similar to BIAB).

There ya go... With such a big grain bill you'll probably want to sparge. Even cold water poured over the grain bag while draining will be effective. What was your mash in qt/lb? Mine are usually around 2.25 qts/lb or more and I *still* do a dunk sparge.

Plus crush... No worries about a stuck sparge so crush 'til you're scared, then crush some more! With my ugly junk corona mill, the plates actually rub together if there's no grain going through. It makes a horrible racket!

I get quit a bit of coarse flour. Decent amount of shredded husks, too, so it's not all flour.


So, super-fine crush plus sparge of some kind for large grain bills, and you'll bump up your efficiency pretty easily.

 

[PhinneyWoodBrews]

Why are squeezing hops a no-no? Is there such a thing as hoppy-ungoodness? The way I look at it, squeezing the hopsock is no different than throwing the hops right into the boil and then dumping them into the fermenter. Even with a hopblocker, the hops get 'squeezed' as the wort pushes through it. I squeeze at flameout and sanitize my gloves first. No off-flavors so far, just hoppy goodness.

I guess my 'no hop squeeze' stance comes from the preponderance of material I've read advocating against it. Your question prompted me to revisit the topic, which on further review seems to be a hotly contested method! I guess we're in the realm of similar discussions as mash minimalists(20 minutes) versus the traditionalists(60+). When homebrewers and even scientists can't agree, I suppose one falls back on whether they like the results they've obtained with their method. I've never squeezed hops, and I like the beer I've made, so I'll probably stick to it. But I certainly appreciate your input and am open to being converted!

Someone who's not just guessing can convince me my methods are wrong.
The thing about homebrewing - try it. If you don't like it, try something different. What works for me might not work for you, and vice-versa. In the end, you get beer, and that doesn't suck.

I heartily agree, cheers!

 

[marcopolo]

Yeah,
I know 17 Lbs is pretty huge for a 1060 beer. I think I can improve my efficiency, but I did like being able to basically steep all my grains & then just go into the boil in the same vessel. Plus the control of mash temp was pretty cool for me. I think there's a trade off with systems & techniques, and that is one of the hidden beauties of homebrewing. We (homebrewers) can mess around and do things that many of the pros can't because it is a hobby not a business & is more affordable.
One extra cost (I think) was a little more propane gas was used for my step mash as opposed to a traditional single infusion & sparge. I think I can also get better efficiency if I change my boil kettle. I have a homemade keggle with a sanke false bottom, and that's why I leave a lot in the kettle.

All said & done, I am a fan of BIAB. BTW, I have fermentation underway in under 2 hours from pitching yeast ! (It is 2nd generation yeast, but still a good sign).

Cheers !

 

[RM-MN]

Yeah,
I know 17 Lbs is pretty huge for a 1060 beer. I think I can improve my efficiency, but I did like being able to basically steep all my grains & then just go into the boil in the same vessel. Plus the control of mash temp was pretty cool for me. I think there's a trade off with systems & techniques, and that is one of the hidden beauties of homebrewing. We (homebrewers) can mess around and do things that many of the pros can't because it is a hobby not a business & is more affordable.
One extra cost (I think) was a little more propane gas was used for my step mash as opposed to a traditional single infusion & sparge. I think I can also get better efficiency if I change my boil kettle. I have a homemade keggle with a sanke false bottom, and that's why I leave a lot in the kettle.

All said & done, I am a fan of BIAB. BTW, I have fermentation underway in under 2 hours from pitching yeast ! (It is 2nd generation yeast, but still a good sign).

Cheers !

Throw that thing away! Just kidding but by leaving 2 gallons of wort in the trub you really hurt your efficiency. I'd boil down until I would need that 2 gallons to get my right quantity into the fermenter and then I'd figure a way to get it there. Trub into the fermenter doesn't hurt anything. Losing 2 gallons of wort does.

Squeeze that bag too. You cannot squeeze hard enough to extract tannins. You have to have too high of a pH to do that and even then you have to heat the mash up to mashout temperature to do that and with BIAB or batch sparging you don't need to do a mashout.

 

[BrewinBromanite]

Squeeze that bag too. You cannot squeeze hard enough to extract tannins.

^^! I've never had any off flavors from doing this. A lot of people hang from a pulley and squeeze, or something similar. I usually mash in a round cooler (typically 10-12 lbs of grain). I've got a couple 10.5 gal bayou classic aluminum pots, with strainer buckets. What I do is put 3 large cans of tomato sauce or whatever (labels and glue removed and cleaned of course), or an appropriately sized smaller pot that fits flush inside the bigger pot, down into the big pot. I move the grain bag from the cooler into the strainer bucket which is sitting in the big pot on top of the cans/smaller pot, giving it plenty of clearance. Then I can take a lid from a smaller pot and push down on the grain bag as hard as I can. Minimal lifting required, (and don't burn hands), and I can maximize the "squeeze". I do that process again after a hot dunk sparge back in the round cooler. Great efficiency this way (I overshoot by most recipes, so actually will cut back on grain, rather than add any. I think people that get decreased efficiency with BIAB either don't care to squeeze for convenience, or are worried about tannins). Point being - whatever works for you that makes tasty beer! Don't worry if it's not a "popular" way to do it. Just have fun and make great beer!


Sent from my iPhone using Home Brew

 

[Magnus314]

Somebody should start a thread about efficiency into bottle/keg.

Seems like some people are leaving behind a whole lot in the kettle, and some are putting everything in. That would really effect the math for "efficiency" quite a bit.

I leave behind maybe 1.5-2 quarts in an 11 gallon batch of basically solid chunks of "stuff" in a trub cone, so not much wort left behind.

But even 2 quarts out of 46 (to end up with 44 qts/11 gallons) would be 4+% difference vs if I just dumped it all in or left a set 1 gallon behind.

That's an 8-9% "efficiency" swing right there for two brewers doing exactly the same process up to the point where they put the wort in the fermenter...

 

[marcopolo]

The reason I ended up leaving so much wort in the brew kettle is because I used a keggle with a false bottom and the wort just stopped draining. I probably could've physically drained & strained the remaining wort to improve my efficiency. If I did that then I wouldn't have added so much extra water to account for the "dead space" in the kettle, and my original gravity would've been higher. I don't know. I reckon I could invest in a more efficient brew kettle, but I kinda like my homemade keggle.

To be quite honest, I'm not too concerned about my efficiency because I don't think that the loss on a few extra pounds of grain is that much money (maybe $5 ?). Bottom line is that I had a lot of fun doing BIAB, and if my finished product tastes great then I'm OK with poor efficiency. That being said, I am in favor of improving both the quality and quantity of my brews. After all, $5 is $5...I could use that to buy a hop rhizome....

If I was a pro brewer & was trying to make a profit then I'd have a different opinion. I am a hobbyist, and all I care about is making a delicious product that my friends & family can enjoy. I think that's part of the beauty of homebrewing - people can do whatever they want.

Cheers !

 

[doug293cz]

Add a dip tube inside the keggle attached to the drain ball valve fitting. The tip of the dip tube should be very close to the lowest point of the keggle bottom. Then add a hose on the ball valve output so that the outlet end of the hose will be at least about a foot lower than the bottom of the keggle when you are draining to the fermenter. This combination will allow you to siphon out most of your dead volume in the keggle. 1/2" tubing should be used for the dip tube. You can make your own, or buy from places like http://www.brewhardware.com/.

Brew on

 

[marcopolo]

Thanks, Doug - I'll give this a shot.

Appreciate the advice.

Cheers ! :rockin:

 

[Magnus314]

The reason I ended up leaving so much wort in the brew kettle is because I used a keggle with a false bottom and the wort just stopped draining. I probably could've physically drained & strained the remaining wort to improve my efficiency. If I did that then I wouldn't have added so much extra water to account for the "dead space" in the kettle, and my original gravity would've been higher. I don't know. I reckon I could invest in a more efficient brew kettle, but I kinda like my homemade keggle.

To be quite honest, I'm not too concerned about my efficiency because I don't think that the loss on a few extra pounds of grain is that much money (maybe $5 ?). Bottom line is that I had a lot of fun doing BIAB, and if my finished product tastes great then I'm OK with poor efficiency. That being said, I am in favor of improving both the quality and quantity of my brews. After all, $5 is $5...I could use that to buy a hop rhizome....

If I was a pro brewer & was trying to make a profit then I'd have a different opinion. I am a hobbyist, and all I care about is making a delicious product that my friends & family can enjoy. I think that's part of the beauty of homebrewing - people can do whatever they want.

Cheers !

I'm not sure how my comment seems to have been seen as an attack on anyone's procedure.

I don't care how anyone chooses to rack from the kettle, I'm just saying that it effects what we call "efficiency", and that some people are talking about one thing and others about another.

If one guy dumps 2 qts of trub into the fementer in a 5 gal batch, then measures the full volume as "efficiency", and another guy carefully separates wort from trub and puts 1/2 gallon less volume, the first guy's "efficiency" will look like it's 10% higher (22 qts instead of 20 at the same OG) - but they'll both end up with the exact same amount of the exact same OG/FG finished beer.

So if you're looking for a certain efficiency, make sure your clear on whether it's mash efficiency, mash/lauter efficiency, kettle efficiency, or efficiency into fermenter.

Otherwise, you may be fruitlessly trying to attain something that doesn't exist, or needlessly leaving behind perfectly good beer!