Efficiency, wort left behind, sparging (BIAB)

[mongoose33]

Morrey and I have been talking about efficiency, squeezing the bag when BIAB, how some people sparge the spent grain....

I offered the possibility that squeezing the bag/grain was functionally analogous to sparging that grain, i.e., rinsing/squeezing essentially accomplished the same thing.

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Yesterday I had a chance to test this in part. I brewed an English bitter of sorts (8# Maris Otter, 3# 2-row, 1# Crystal 60L) using BIAB. Efficiency was on a par with what I was able to do using a traditional mash tun.

I started with 7.25 gallons of water, and after squeezing the bag after mashing I ended up with just about 6.6 gallons of wort. Hard to be certain of the exact amount due of expansion of the hotter water, but about that. I was happy with what I had as a yield.

My pre-boil gravity was 1.053, just a smidge short of the 1.054 I had using this recipe the last time using a mash tun.

***************

Here's the experimentish approach: After squeezing out what I could, I put the bag and grain in a 5-gallon bucket. Added 2 gallons of RO water to "sparge" with and mixed it up well with a mash paddle. I then hoisted the bag to let it drain into the bucket, and then squeezed until I could recover those 2 gallons.



Wow. I measured the gravity of that wort, and it was 1.020! My brewhouse efficiency is about 77 percent, not quite as good as usual.

But I was shocked by how much sugar survived my squeezing. I usually record first-runnings and second runnings when using a traditional mash tun; that ranges from 1.026 to 1.035, depending on when I start sparging.

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For those will wonder, my mill gap is about 1.020, same as the last three BIAB's I've done. One might wonder if it has grown larger by the adjustment moving a bit, but it was just as hard and long to crush that grain as it was before, so I don't think it has really done that.

Mash temp was 151 degrees, and it held for most of the 60-minute mash. Typically I might mash at 153 or 154, but I want this recipe to produce a bit drier finish. Mash pH was 5.28 measured at 15 minutes into the mash. I stirred the mash well at the 15-minute mark and again at 30 minutes.

***********

This is only one attempt to look at this issue, but after a first try, the idea that squeezing is analogous to sparging doesn't seem to be the case. Clearly there was a lot of sugar left in the grain after squeezing. The amount of retained water in the spent grain was pretty low, so one would have thought there was enough squeezed out of the grain.

Now, I could have gotten more out of the original grain but I reached a pre-boil volume that was fine, so I just stopped there. Morrey has a sort of basket arrangement he uses and he can press the grain drier than I can, so perhaps with more pressure more of that sugar might come out of the grain.

Thoughts on this?

 

[IslandLizard]

Excellent experiment!

It reveals what most of us squeeze critics have been expecting all along. Squeezing helps, but a decent sparge is 2nd to none. Physics can be proven.

 

[Morrey]

Mongoose33 and I have pondered how much sugar we are leaving behind by just squeezing, so his experimentation was well thought out. I plan to brew a Patersbier later today and will report back the SG of my sparge test similar to the way Mike has done his. I have an Arbor Fab 400 um mesh basket with a press plate. I average .05 gal of water absorption by the grains, and based on Mongoose33's absorption rate, seems both are quite similar.

I'll post my numbers late today, and like Mongoose33, am interested in thoughts of other HBT members.

 

[Kharnynb]

tagging for reading

I've always been a squeeze, sparge squeeze guy out of need more than want, but i tend to hit my gravities with about 75% efficiency with storemilled grain.

 

[Epos7]

My last 3-4 batches have been ten gallon batches, after brewing 10-15 five gallon batches after taking up the hobby last year.

10 gallons in my 15 gallon kettle means I need to do a partial volume mash, so I usually mash in 10.5 gallons, then put a steel colander in the top of my kettle and put the bag in there. I heat up some water to ~160 on my stove top, adjust it to the same water profile as my mash water, and pour it over the bag until I reach my boil volume. I find I do get an efficiency boost doing this as opposed to just squeezing, typically in the range of 1-3%, although there was one batch where efficiency didn't change.

 

[brewskiez]

My last 3-4 batches have been ten gallon batches, after brewing 10-15 five gallon batches after taking up the hobby last year.

10 gallons in my 15 gallon kettle means I need to do a partial volume mash, so I usually mash in 10.5 gallons, then put a steel colander in the top of my kettle and put the bag in there. I heat up some water to ~160 on my stove top, adjust it to the same water profile as my mash water, and pour it over the bag until I reach my boil volume. I find I do get an efficiency boost doing this as opposed to just squeezing, typically in the range of 1-3%, although there was one batch where efficiency didn't change.

Thanks for sharing that and to the OP. That's normally how I do mine to the same effect always wondered if it was really worth it don't know if 1-3% is really worth it. I have been lazy lately with taking OG's my beer never fails to get me buzzed and I'm not to picky as long as I know what's in it.

 

[wilserbrewer]

No matter how strong you are, you can't squeeze sugar. The amount of sugar left will be wort gravity and grain absorption dependent. With a sparge your absorbed wort will most likely be a lower gravity, more substantially so with higher gravity beers.

 

[SlitheryDee]

This is definitely interesting, but how do I use it when brewing? Can I hold out a couple of gallons from the kettle, perform a dunk-sparge like the OP did, mix it all together, and realize a notable increase in efficiency?

 

[TheMadKing]

Squeezing cannot improve MASH efficiency but it can improve brewhouse efficiency. You seem to be measuring mash efficiency, so it will have no effect.

@Doug293cz explained it very well (to me) in this thread when I used to think the same thing: https://www.homebrewtalk.com/showthread.php?t=569802&page=5

 

[mongoose33]

Squeezing cannot improve MASH efficiency but it can improve brewhouse efficiency. You seem to be measuring mash efficiency, so it will have no effect.

@Doug293cz explained it very well (to me) in this thread when I used to think the same thing: https://www.homebrewtalk.com/showthread.php?t=569802&page=5

I was measuring brewhouse efficiency. At that point where I'm squeezing, the mash is done doing what it's done, agreed.

Something I may try is using a traditional mash tun, drawing off the first runnings, then squeezing. With the grain bills I use (usually 11 or 12#), about 2.5 gallons of the 4 gallons of strike water will be recovered as first runnings. I could probably get more if I were more patient, but that's the point where I typically add sparge water.

So i'm thinking, 4 gallons strike water, squeeze, then another 4 gallons of sparge water for a batch sparge, drain off the second runnings, then squeeze again. I may only need about 3.5 gallons of sparge water if I'm squeezing.

 

[pricelessbrewing]

Squeezing cannot improve MASH efficiency but it can improve brewhouse efficiency. You seem to be measuring mash efficiency, so it will have no effect.

@Doug293cz explained it very well (to me) in this thread when I used to think the same thing: https://www.homebrewtalk.com/showthread.php?t=569802&page=5

Mash efficiency = lauter * conversion. You're getting conversion and mash mixed up, which is totally understandable.

 

[pricelessbrewing]

The phrase "rinsing sugar" is extremely misleading. There is no dry sugar in the mash or grain or wort. It's a bad analogy.

The best way to think of it is via dilution.

If you put a sponge into some juice, you have a very good analogy for the grains and wort.

Squeezing the sponge (grain) releases some of the juice (wort), but it will still be at the same gravity as the rest of the juice (wort).

Batch sparging is analogous to taking the sponge, and dunking it in a new pot of water, then squeezing and repeating a couple times.

By using the dilution/absoption model, you can explain sparging, grain absorption, mash tun loss, kettle loss, etc all using one simple model. The only real hurdle with this is that your wort volume is greater than just the strike water volume, just as a sugar solution volume is greater than the respective water volume. This can be easily modelled using the traditional 'extract' model for the initial strike volume. I have a google sheet to compare this side by side using the 'extract' model all the way through, and the 'diluation' model all the way through, the difference is ~0.2% ie negligible (IMO)

 

[TheMadKing]

Mash efficiency = lauter * conversion. You're getting conversion and mash mixed up, which is totally understandable.

Yep you're right! I was forgetting that lauter efficiency takes into account grain absorption, thanks!

Reviewed my Brukaiser and I was just forgetting the definition of lauter efficiency http://www.braukaiser.com/wiki/index.php/Batch_Sparging_Analysis

 

[SlitheryDee]

The phrase "rinsing sugar" is extremely misleading. There is no dry sugar in the mash or grain or wort. It's a bad analogy.

The best way to think of it is via dilution.

If you put a sponge into some juice, you have a very good analogy for the grains and wort.

Squeezing the sponge (grain) releases some of the juice (wort), but it will still be at the same gravity as the rest of the juice (wort).

Batch sparging is analogous to taking the sponge, and dunking it in a new pot of water, then squeezing and repeating a couple times.

By using the dilution/absoption model, you can explain sparging, grain absorption, mash tun loss, kettle loss, etc all using one simple model. The only real hurdle with this is that your wort volume is greater than just the strike water volume, just as a sugar solution volume is greater than the respective water volume. This can be easily modelled using the traditional 'extract' model for the initial strike volume. I have a google sheet to compare this side by side using the 'extract' model all the way through, and the 'diluation' model all the way through, the difference is ~0.2% ie negligible (IMO)

I'm trying to work out the effect of sparging and squeezing in some way that makes sense to me. Is there anything wrong with looking at it like this:

Let's say you have a post mash 7 gallons of wort. You've done no sparge, squeezed the bag and the preboil gravity is 1.047.

Then lets say you have another identical batch, except you've held out 2 gallons to sparge with. The same grain bill is now in a reduced volume of water, so the sugars are more concentrated. You now have 5 gallons of 1.066 wort and two gallons of 1.000 water. You could just combine the two to arrive at your 1.047 wort, or you could give the grains another dunk and squeeze and get something more out of them. So you dunk the grains, squeeze them out, and your "sparge" water now has a gravity of 1.010. Combining the two should average out to something more than 1.047

(.066 + .066 + .066 + .066 +.066 + .010 + .010)/7 = .050

So the gravity of your post sparge wort is 1.050. You've gained yourself 3 points.

 

[Morrey]

Ok so along with Mongoose33, I did my part of the test. In my case I have an Arbor Fab BIAB mesh basket with a press plate. 11# grains, 6.75 G pre boil volume measuring 1.045. Typical boil off should drop me in right at 1.055 into fermenter. Mongoose33 and I both use Wilserbags, but I have the mesh basket too so we wanted to see if this had an impact.

I take my spent grain basket and hold it over a bucket and spray a stream of water over the grains. I also pressed with press plate and one gallon of collections was 1.010. I went for another gallon, pressed and SG went to 1.006 for the two gallon sparge. As expected my first gallon of sparge was more concentrated than gallon two.

Sooooo, how to proceed now? Should I mash with one gallon less, rinse as explained and add the sparge back into my boil?

***This is what I am trying to get my head around, SlitheryDee. What would happen to my preboil SG of 1.045 if I reduced the strike volume by 1 gallon to thicken the mash. Will 1.045 go up or down?

 

[TheMadKing]

Ok so along with Mongoose33, I did my part of the test. In my case I have an Arbor Fab BIAB mesh basket with a press plate. 11# grains, 6.75 G pre boil volume measuring 1.045. Typical boil off should drop me in right at 1.055 into fermenter. Mongoose33 and I both use Wilserbags, but I have the mesh basket too so we wanted to see if this had an impact.

I take my spent grain basket and hold it over a bucket and spray a stream of water over the grains. I also pressed with press plate and one gallon of collections was 1.010. I went for another gallon, pressed and SG went to 1.006 for the two gallon sparge. As expected my first gallon of sparge was more concentrated than gallon two.

Sooooo, how to proceed now? Should I mash with one gallon less, rinse as explained and add the sparge back into my boil?

***This is what I am trying to get my head around, SlitheryDee. What would happen to my preboil SG of 1.045 if I reduced the strike volume by 1 gallon to thicken the mash. Will 1.045 go up or down?

1.045 will go up. SlitheryDee's analogy is very accurate. If your 1.045 goes up in your initial mash, then your sparge gravities will also be slightly elevated from what they were as well. You will get more sugars from the grain by sparging. Check out that Brukaiser link I posted above. It explains it all in great detail.

So on how to proceed, it's up to you. Is the extra efficiency worth the effort of BIAB sparging? It's not to me, so I'm perfectly content with my 70-75% efficiency and I adjust my recipes accordingly to keep doing no-sparge.

 

[Morrey]

1.045 will go up. SlitheryDee's analogy is very accurate. If your 1.045 goes up in your initial mash, then your sparge gravities will also be slightly elevated from what they were as well. You will get more sugars from the grain by sparging. Check out that Brukaiser link I posted above. It explains it all in great detail.

Will do. In my case the sparge was quick and easy w/o fuss and muss. It would take all of 2 minutes to shoot water over the spent grains, press and collect a gallon of sparge water.

The good thing about my water source is that after a Ward Lab test, my water is darn close to RO water. This is a big factor in my thinking as well.

 

[Morrey]

TheMadKing, let me ask you (and all) if this would be accurate and I am just posing arbitrary numbers:

I mash 10# grains in 10 G strike water and get 1.025. SO if I reduce my strike water to 5 G with the same grain bill with all factors remaining constant, will my gravity be 1.050?

 

[TheMadKing]

TheMadKing, let me ask you (and all) if this would be accurate and I am just posing arbitrary numbers:

I mash 10# grains in 10 G strike water and get 1.025. SO if I reduce my strike water to 5 G with the same grain bill with all factors remaining constant, will my gravity be 1.050?

Yes, if you cut your strike water in half, your first runnings gravity should be doubled. There may be some additional factors in play though, such as loss of conversion efficiency, that will make it not quite double in an experiment.

 

[pricelessbrewing]

Let's say you have a post mash 7 gallons of wort. You've done no sparge, squeezed the bag and the preboil gravity is 1.047.

If you had 7 gallons @ 1.0470, and then changed your process from full volume mash (no sparge) to sparging with 2 gallons, you would be left with 7 gallons @ ~1.0518. Gaining almost 5 points, and going from ~81% lauter efficiency to ~89% lauter efficiency.

This can be easily done using my mash calculator (link in sig).

***This is what I am trying to get my head around, SlitheryDee. What would happen to my preboil SG of 1.045 if I reduced the strike volume by 1 gallon to thicken the mash. Will 1.045 go up or down?

The mash gravity is purely a function of mash thickness, and conversion efficiency. If you make the mash thicker (use less water), then the mash gravity goes up because it's more concentrated. This again can be seen easily in my mash calculator.

TheMadKing, let me ask you (and all) if this would be accurate and I am just posing arbitrary numbers:

I mash 10# grains in 10 G strike water and get 1.025. SO if I reduce my strike water to 5 G with the same grain bill with all factors remaining constant, will my gravity be 1.050?

Not quite, due to the fact of wort volume being greater than water volume. As I stated previously, wort increases in volume during the mash due to sugars (and probably a small amount due to lipids, protein, and beta glucans).

Adjusting to a realistic example:

10# of grain in 10 gallons of water should yield ~ 1.030-1.034 depending on how good your conversion is. We will use 1.032 for simplicity.

If we halved the strike water, then the first runnings gravity (from the mash after squeezing), would be ~1.058. This is notably less than 32 * 2 = 64.

This too can be done in my mash calculator.

For a more concise formulation, I will have a cleaned up googlesheet soon that might help think in this perspective. It's really as simple as dilution and absorption.

 

[Morrey]

Yes, if you cut your strike water in half, your first runnings gravity should be doubled. There may be some additional factors in play though, such as loss of conversion efficiency, that will make it not quite double in an experiment.

When I did my test yesterday, I got 1.045 from a full volume strike, then extracted (sparged) another 1.010 (one gallon) runnings from a grain basket that I was preparing to toss.

My math was less impressive than SlitheryDee, but I determined I may gain .003 SG by reducing my strike volume by one gallon, sparging and adding the gallon of running's back into the boil kettle.

Like you, is .003 even worth it? Some would say yes, some say no, but either way it is good to know this.

 

[SlitheryDee]

TheMadKing, let me ask you (and all) if this would be accurate and I am just posing arbitrary numbers:

I mash 10# grains in 10 G strike water and get 1.025. SO if I reduce my strike water to 5 G with the same grain bill with all factors remaining constant, will my gravity be 1.050?

I've been playing around with beersmith, and it seems to think there's a pretty linear relationship between water volume and gravity. I'm just looking at overall batch size though, I can't figure out how to make it tell me what you're asking in the mash tab. If you double the batch size, OG does indeed go down by half though.

I have a feeling that there are other potential differences though. For instance, up to a point a thicker mash that puts all the starches and enzymes in close proximity should theoretically be somewhat better for conversion. Then again maybe there's yet another aspect of a thicker mash that mitigates that effect though. Higher viscosity could be detrimental due to not allowing the wort to flow as freely and get everything in contact with each other. There are so many potential variables, but I'd be willing to be that you can generally assume that what you're asking is true.

 

[pricelessbrewing]

I've been playing around with beersmith, and it seems to think there's a pretty linear relationship between water volume and gravity. I'm just looking at overall batch size though, I can't figure out how to make it tell me what you're asking in the mash tab. If you double the batch size, OG does indeed go down by half though.

This is because beersmith assumes you will have a constant brewhouse efficiency regardless of process or recipe. This isn't realistic.

 

[Morrey]

I've been playing around with beersmith, and it seems to think there's a pretty linear relationship between water volume and gravity. I'm just looking at overall batch size though, I can't figure out how to make it tell me what you're asking in the mash tab. If you double the batch size, OG does indeed go down by half though.

I have a feeling that there are other potential differences though. For instance, up to a point a thicker mash that puts all the starches and enzymes in close proximity should theoretically be somewhat better for conversion. Then again maybe there's yet another aspect of a thicker mash that mitigates that effect though. Higher viscosity could be detrimental due to not allowing the wort to flow as freely and get everything in contact with each other. There are so many potential variables, but I'd be willing to be that you can generally assume that what you're asking is true.

I see both sides of the equation. If the solution was less concentrated it seems (to me) that conversion may be easier since there is some "free room" in the solution. The other side of the equation is the enzyme proximity and reaction relating to conversion as you make in a good point. Price referenced his link that I am going to read tonight. We may be struggling over .003 SG points, but I feel the more we know, the better brewers we become. Mongoose33 feels the same way as he prompted me to join in his test being discussed.

 

[SlitheryDee]

This is because beersmith assumes you will have a constant brewhouse efficiency regardless of process or recipe. This isn't realistic.

Yeah that's true, and I know absolutely nothing about what my efficiency would be at less than BIAB water to grain ratios. I've only ever done full volume mashes to this point.

 

[mongoose33]

This all started when Morrey and I were cogitating over what's left behind and why.

Some people argued (can't recall where) that you just increase the grain bill a bit using BIAB, and you'll be fine. At our scale (5-10 gallons or so) the cost increase is minimal, unlike a brewery where another pound per 5 gallons can run into significant money.

Then there was the squeezing issue. Do I or don't I? I squeezed in the first couple of BIABs I did, and I had essentially the same efficiency as I did using the regular mash tun--and this was using the same grain bill. I wondered, as Morrey and I chewed on this, whether squeezing was analogous to sparging, whether squeezing out remaining wort was more or less equivalent in sugar recovered to sparging.

So that's what's brought this on. I like the sponge analogy, but squeezing the grain squeezes out the wort; would it be more effective than just sparging?

My experience says yes--when I poured in the two gallons of water to sparge, I stirred quite a bit, then took a sample. Gravity was 1.008, suggesting that sparging after squeezing wasn't going to yield much. But then I drained *and* squeezed, and the gravity shot up to 1.020. That tells me the sponge analogy is fairly good, and that the water from sparging entered the grain bits and then when squeezed out took a lot of the remaining sugar with it.

I'm not sure where I go with this. With squeezing my efficiency is effectively equivalent to a traditional mash tun method. If the goal with BIAB is to simplify and reduce time spent, then that should be good enough.

 

[Epos7]

Here are some of my observations. I need to check the upper range of volume markings on my kettle to confirm they are off by the same 0.3 gallons as the lower end. I plan to do that tomorrow - I'll report back if I find my volumes were off.

Row 2 Hill 56 Pale:
total grain bill: 20lb
strike volume: 10.5 gallons
mash gravity at 60 minutes: 1.062
after sparging to reach 13.2 gallons @150F: 1.047

Brulosophy Best Blonde Ale:
total grain bill: 17.48lb
strike volume: 10.5 gallons
mash gravity at 60 minutes: 1.053
after sparging to reach 12.05 gallons @ 142F: 1.046

Sasquatch Pale Ale:
total grain bill: 19lb
strike volume: 10.5 gallons
mash gravity at 60 minutes: 1.053
after sparging to reach 12.35 gallons @ 147F: 1.048

 

[SlitheryDee]

Would it be helpful if I did two mashes with the same grain bills, one with 3.5 gallons of strike water and then a dunk sparge, and one a more traditional BIAB style with 7 gallons of strike water and recording the SG of each step? I've really got an urge to see what the numbers would be on the mash gravities, sparge water gravity, and combined sparge and mash water gravity.

 

[mongoose33]

Would it be helpful if I did two mashes with the same grain bills, one with 3.5 gallons of strike water and then a dunk sparge, and one a more traditional BIAB style with 7 gallons of strike water and recording the SG of each step? I've really got an urge to see what the numbers would be on the mash gravities, sparge water gravity, and combined sparge and mash water gravity.

Sure--I think this is the approach needed as we move forward, i.e., people actually trying different approaches and comparing.

I had a question about the amount of strike water and its influence on the mash. If I used, say, 4 gallons as strike as opposed to 7.25 gallons, would the enzymes in a 4-gallon strike be in closer proximity to the starch than in a more dilute 7.25 gallons?

So what you propose above is very interesting.

 

[SanPancho]

kaiser has lengthy writeup on mash thickness vs efficiency. i dont remember exactly, but if you combine full volume (loose) mash with enough time you get maximal efficiency, if i recall. solubility is higher in the looser mash. just takes time for enzymes to do there work as they have to "swim" a littler farther in search of starches.

i would see 3-5% brewhouse efficiency bumps by squeezing the bag, then plopping it into a bit of hot water in a 2nd small kettle for 10-15 minutes. stirring helps. 85% was not hard to hit.

if i want high gravity beer it makes sense, otherwise i just end up using the sparged wort to make a starter. usually boil it down by half, roughly.

 

[Morrey]

i dont remember exactly, but if you combine full volume (loose) mash with enough time you get maximal efficiency, if i recall. solubility is higher in the looser mash. just takes time for enzymes to do there work as they have to "swim" a littler farther in search of starches.

This^^^^

Mongoose33 and I keep looking at this aspect of our process.

I made this non-scientific statement back a few posts ago, but this is just my thought with no scientific basis:


I see both sides of the equation. If the solution was less concentrated it seems (to me) that conversion may be easier (more productive) since there is some "free room" in the solution.


Now it all comes down to efficiency. If I got 80% with 7.25G full volume strike, will I also get 80% with 6.25G of strike, then add back in a gallon of 1.010 sparge? The only way this will work is if efficiency with the slightly thicker mash remains at 80%. If the efficiency drops, sparge efforts may potentially be counter-productive.

 

[SanPancho]

you're forgetting the other variables, time and temp. if you held temp constant, you could still get thick and thin mashes to the same gravity. time would be the variable.

 

[pricelessbrewing]

you're forgetting the other variables, time and temp. if you held temp constant, you could still get thick and thin mashes to the same gravity. time would be the variable.

Not quite, there's a hard limit on mash gravity as a function of mash thickness. The maximum mash gravity corresponds to 100% conversion efficiency.

If you rephrased to

you're forgetting the other variables, time and temp. if you held temp constant, you could still get thick and thin mashes to the same conversion efficiency. time would be the variable.

Then it would be true.

 

[doug293cz]

This is definitely interesting, but how do I use it when brewing? Can I hold out a couple of gallons from the kettle, perform a dunk-sparge like the OP did, mix it all together, and realize a notable increase in efficiency?

Yes. And if you squeeze, sparge, squeeze, you will get an even bigger increase in efficiency. It's up to you to decide if the increased efficiency is worth the increased effort.

Brew on

 

[Morrey]

Yes. And if you squeeze, sparge, squeeze, you will get an even bigger increase in efficiency. It's up to you to decide if the increased efficiency is worth the increased effort.

Brew on

Doug, realizing there are too many variables to nail down specifics, what is your general thought on how many SG point gains one may see by doing a process as you mention?

 

[SlitheryDee]

Yes. And if you squeeze, sparge, squeeze, you will get an even bigger increase in efficiency. It's up to you to decide if the increased efficiency is worth the increased effort.

Brew on

Well of course I'm going to have to do one and see how it goes before I can make that decision. On the surface, simply dunking the spent grains and squeezing them out again doesn't seem like a significant addition to my brew day. I've already laid out the recipes for the tests I mentioned earlier. Maybe I'll find the time to do one this weekend.

 

[pricelessbrewing]

For those testing this for yourself, if you don't mind I would appreciate it if you filled out this form as well and reported the outputs. https://pricelessbrewing.github.io/BiabCalc/#EfficiencyEvaluation

I squeeze, sparge (dunk/batch style), and squeeze again. The only thing takes about 15 minutes, and I get about 8-14% more lauter efficiency which for me is worth it. Sometimes I don't sparge, sometimes I do.

 

[Pointyskull]

Excellent experiment!

It reveals what most of us squeeze critics have been expecting all along. Squeezing helps, but a decent sparge is 2nd to none.

I've been a bag squeezer, but I'd be willing to give sparge a test or two.
How are BIAB-ers handling the process/technique of sparging?
I hoist my bag on a pulley over the brew kettle and squeeze, but if I'm going to sparge are there links anyone has with recommended technique?

thx

 

[mwill07]

last week, I hit 85% brewhouse efficiency, which was higher than expected. My process has a couple extra steps, but doesn't take any more time. My rig is a recirculating e-keggle BIAB. I should add that the grains are double-crushed.

Here is my current process:

1. heat up full volume of water, including all mineral and acid additions.
2. before doughing-in, pull one gallon of water. put that to the side for later.
3. dough in, mash as usual.
4. Mash for an hour or more, and do an iodine test for conversion just to be sure.
5. when mash is almost done, I boil that extra gallon of water on my kitchen stove. I add that into my old 5 gallon igloo cooler mash tun at boiling temp.
6. when the mash is done, I hoist out the bag, suspended with a locking pulley. I put on some silicone gloves and squeeze he heck out of the bag - I try to get as much as I can. I also crank up the heater at this point to start getting ready to boil.
7. once I'm satisfied with the manual squeeze, I put the bag into the gallon of still hot water. The water should be about 185 dF or so.
8. give it a good stir, let it sit for a bit, and drain directly into keggle. The boil should just be getting started. I probably should vorlauf but don't and haven't really noticed an impact on clarity.
9. Once the mash-tun stops running freely, I give it a good squeeze. I actually will let it continue draining into the keggle throughout the boil and give it a squeeze every time I walk by. I am trying to extract every single drop of worty goodness I can.

the point is, I'm re-using my old equipment to do this, and it doesn't add any extra time to the brew-day. It's one extra step, but it's really not a big deal.


Here is a recent brew day with some pics of my process and rig.

 

[z-bob]

I just bought a Wilser bag (it gets here today ) I've been doing a squeeze/sparge/squeeze again. What I want to try is forget about the sparge and do a full volume mash, now that I have a kettle and a bag large enough to accommodate that.

I will be leaving sugar behind in the spent grain, but it will be considerably diluted. I'm hoping that overall I don't lose much efficiency. I'm pretty sure that's how the Aussies do it.