BIAB sparge - not for me

[soccerdad]

this could maybe go in the 'funny things' thread

I was doing other mashy things

 

[Psylocide]

this could maybe go in the 'funny things' thread

I don't know why Gavin insists on doing all sorts of weird mashy things when he knows that it's best to just boil the grain for 30 min, chuck in a handful of hop pellets and call it a day.

 

[craigmw]

I've been trying sparging with my last few BIAB brews. I've been getting a bump in efficiency, from a routine 75% to about 80% with sparging. I've usually done this with a cold water sparge, but the last time, I maintained sparge temp in a 5 gallon cooler. I note roughly the same bump in efficiency with cold water (75F) vs. hot water (168F), which fits with some of BrewKaiser's experiments. So, the efficiency increase is noticeable, but not profound enough to be worth the trouble. I have noted a much clearer wort however, so for what it's worth, that is an improvement over standard BIAB methods (e.g. squeezing the bag for all it's worth). I'm brewing a 15 gallon batch this weekend in a 20g kettle, and the only way to achieve this is with a sparge step. I'll let you all know how it goes.

 

[AnOldUR]

Regardless of method and mash parameters including rest times, temperatures of the rests and crush quality. Near 100% conversion efficiency is an obtainable objective. It is the basis all brewing models I have read about.

If those brewing models were based on dollars, I would agree. But when talking about no-sparge, "it results in a richer and more-intense malt flavor, with less harshness compared to other methods, according to (Gordon) Strong."

This quote was made in regard to the advantages of lower efficiency from doing a traditional no-sparge. It might be wrong, but to me, crushing fine and/or using a very thin mash puts you in the same place you'd be using any method to maximize efficiency much beyond 70-75% (random numbers, but you get the idea). Not necessarily bad beer, but not the absolute best it could be.

 

[Homercidal]

I sparge, when doing BIAB. My kettle size makes that mandatory.

I'm not sure I'd still do it if my kettle were big enough to hold the full volume. Isn't there some science behind a water-to-grist ratio? If there is no good reason to go with 1.25:1 ratio, then why is it taught?

In any case, the difference between a Full Volume BIAB and a dunk sparge BIAB has got to minimal. Both get the wort very diluted in the end and when you consider the gravity of the remaining wort, it's not much at all in terms of remaining sugars.

Remember that many of the methods and equipment that homebrewers started out with was based on commercial brewing systems in an attempt to emulate their process. Therefore we have mash tuns with false bottoms, etc. It's simply not practical for any professional brewer (other than a nano) to utilize a BIAB approach. The evolution took time. Who knows what a homebrewer might come up with next?

 

[soccerdad]

If those brewing models were based on dollars, I would agree. But when talking about no-sparge, "it results in a richer and more-intense malt flavor, with less harshness compared to other methods, according to (Gordon) Strong."

This quote was made in regard to the advantages of lower efficiency from doing a traditional no-sparge. It might be wrong, but to me, crushing fine and/or using a very thin mash puts you in the same place you'd be using any method to maximize efficiency much beyond 70-75% (random numbers, but you get the idea). Not necessarily bad beer, but not the absolute best it could be.

Somewhere there is a rather lengthy explanation of how and why "no sparge" as it first came out differs greatly from BIAB. I can't recall ... maybe Pat at biabrewer.info In any case, the idea was that the 'no sparge' brewers (who would otherwise 3V with sparge) were happy to add grain and accept lower efficiency in favor of saving time and effort. On the other hand it appears that BIAB brewers have found ways to not decrease efficiency and still make excellent beer. I am not a judge and I do not have a sophisticated pallet, but from what I have seen, on a percentage basis, BIAB brewers win as many awards and get just as high score sheets as 3V brewers, so 'absolute best' may be a subjective rather than objective in many cases.

 

[Gavin C]

If those brewing models were based on dollars, I would agree. But when talking about no-sparge, "it results in a richer and more-intense malt flavor, with less harshness compared to other methods, according to (Gordon) Strong."

This quote was made in regard to the advantages of lower efficiency from doing a traditional no-sparge. It might be wrong, but to me, crushing fine and/or using a very thin mash puts you in the same place you'd be using any method to maximize efficiency much beyond 70-75% (random numbers, but you get the idea). Not necessarily bad beer, but not the absolute best it could be.

I totally see your point and am nowhere near experienced enough to have explored this in detail myself. My evidence base is weak no doubt.

I'm only really trying to disconnect the link between crush size and final efficiency with my earlier rambling post. particulary with regard to the argument.

ie: "I can't get those numbers because I don't crush as fine"

The conversion in the mash should be complete or negligably close to it regardless of crush size.

I'm not suggesting that targeting higher efficiency numbers should be an end in and of itself but merely suggesting that managing the physical properties of the mash to achive full conversion makes sense if residual starches are to be avoided. It's something we all try to do.

Crush fatter and mash longer or do something else to achieve this near complete conversion and eliminate starch in the wort.

The difference (which I know you are well aware of) allowing the bump in efficiency with a bag manifold over other types of no sparge brewing is the increased lautering efficiency. With a conventional setup this I suppose would equate with potentially over-sparging which I think is the crux of the too high an efficiency debate.

I could lower my efficiency by not squeezing as much to bring me down to 75% with minimal extra grain or no change at all for a 1.06 beer where the grain bill is higher and lautering efficiency reduced acordingly.

 

[djt17]

A hassle sparge is just not worth it.

Hassle Sparge...I like that, I also did a biab sparge...once. Full volume since. (I also use my ZapPap pail to drain the bag + a "mofo" squeeze!)

 

[Homercidal]

I totally see your point and am nowhere near experienced enough to have explored this in detail myself. My evidence base is weak no doubt.

I'm only really trying to disconnect crush quality and final efficiency with my earlier rambling post.

ie: "I can't get those numbers because I don't crush as fine"

The conversion in the mash should be complete or negligably close to it regardless of crush size.

I'm not suggesting that targeting higher efficiency numbers should be an end in and of itself but merely suggesting that managing the physical properties of the mash to achive full conversion makes sense if residual starches are to be avoided. It's something we all try to do.

Crush fatter and mash longer or do something else to achieve this near complete conversion and eliminate starch in the wort.

The difference allowing the bump in efficiency with a bag manifold over other types of no sparge brewing is the increased lautering efficiency. With a conventional setup this I suppose would equate with potentially over-sparging which I think is the crux of the too high an efficiency debate.

I could lower my efficiency by not squeezing as much to bring me down to 75% with minimal extra grain or no change at all for a 1.06 beer where the grain bill is higher and lautering efficiency reduced acordingly.

The conversion may happen in any case if moisture of the right temperature can make it's way into the particle, but a finer crush will better allow those sugars to be released from the particle, rather than remain inside of it.

 

[JONNYROTTEN]

Yes I agree. A hassle sparge is just not worth it. I like to do a small pour over sparge as the bag hangs over the kettle on a ratchet pulley, not so much for the point of sparging but more so as a pre boil volume adjustment. This allows me to be lax on strike volume and make an accurate adjustment with a sparge.

This is what I do

 

[Gavin C]

The conversion may happen in any case if moisture of the right temperature can make it's way into the particle, but a finer crush will better allow those sugars to be released from the particle, rather than remain inside of it.

Totally agree. Diffusion is in play. The bigger the particle the more time needed for that to occur.

 

[broadbill]

Totally agree. Diffusion is in play. The bigger the particle the more time needed for that to occur.

Although in theory this is true, in practice a 30-60 minute mash is long enough to get full conversion regardless of particle size. If I remember Braukaiser's experiments, under most "normal" conditions, one can assume near complete conversion efficiency (upwards of 90% anyway) and therefore the lauter should be targeted if you are looking for improvements in efficiency.

In short, the rate limiting step is the lauter.

 

[Homercidal]

Although in theory this is true, in practice a 30-60 minute mash is long enough to get full conversion regardless of particle size. If I remember Braukaiser's experiments, under most "normal" conditions, one can assume near complete conversion efficiency (upwards of 90% anyway) and therefore the lauter should be targeted if you are looking for improvements in efficiency.

In short, the rate limiting step is the lauter.

IIRC an average crush is likely to be converted rather quickly under good conditions. I think pH has a hand in how fast it occurs as well, although I may be mistaken. Also mash dilution is supposed to be a factor as well, as it takes longer for the enzymes to make contact with, and modify the starches if they are not in close quarters. This is why stirring the mash is very helpful.

 

[PlexVector]

IIRC an average crush is likely to be converted rather quickly under good conditions. I think pH has a hand in how fast it occurs as well, although I may be mistaken. Also mash dilution is supposed to be a factor as well, as it takes longer for the enzymes to make contact with, and modify the starches if they are not in close quarters. This is why stirring the mash is very helpful.

Mash dilution effects pH so you do water adjustments to compensate.

The following is from Beersmith blog:
http://beersmith.com/blog/2015/05/07/mash-ph-and-why-it-matters-for-all-grain-beer-brewing/


"A lower mash pH (near 5.2) has the following benefits:

-Improved enzyme activity during the mash, leading to better conversion of starches to sugars
-Lower pH in the finished wort which improves yeast health during fermentation, and also inhibits bacteria growth
-Improved hop extraction rates in the boil
-Better protein and polyphenol precipitation both during the cold break and post fermentation
-Improved clarity in the finished beer with reduced chill haze
-Improved flavor and clarity stability as the beer ages"

 

[Gavin C]

Also mash dilution is supposed to be a factor as well, as it takes longer for the enzymes to make contact with, and modify the starches if they are not in close quarters.

More dilute mashes seem to perform numerically better all else being equal. These thinner mashes seem to produce better efficiencies while the fermentability of the resulting wort seems to remain unchanged.

From the Kaiser's page.

Fermentability
Contrary to common believe no attenuation difference was seen between a thick mash (2.57 l/kg or 1.21 qt/lb) and a thin mash (5 l/kg or 2.37 qt/lb). Home brewing literature suggests that thin mashes lead to more fermentable worts, but technical brewing literature suggests that the mash concentration doesn't have much effect in well modified malts [Narziss, 2005].


Efficiency
A significant difference was however found in the efficiency. The brewhouse efficiency of the tick mashes remained almost constant between 58 and 60% over the temperature range of the experiments, but the brewhouse efficiency for the thinner mash showed a strong dependency on the temperature and was always better than the efficiency of the tick mash. That leads to the conclusion that thinner mashes perform better and allow for better extraction of the grain. Briggs also reports that thinner mashes can convert more starch but that most of the conversion potential is reached at a water to grist ratio of 2.5 l/kg [Briggs, 2004]

 

[MarshmallowBlue]

I often use my fermenting bucket for the sparge dunk, easy to just drop a few gallons of water in that i boiled with an electric kettle.

This is what I do as well.

 

[wilserbrewer]

Fwiw, dunk sparging in your fermenter may not be the best practice. The preboil wort is not sanitary, so you are contaminating your fermenter. Yes, I realize it gets sanitized, it's just best practice not to use the same equipment pre and post boil.

 

[ScrewyBrewer]

I always sparge my BIAB on my 15 gallon system the most I get out of it is a 6% alcohol beer, without adding adjuncts. I target pH 5.2 to 5.3 at mash temperature and use a thinner 2.25 mash thickness which usually translates into 23 pounds of double crushed grain.

 

[Kharnynb]

Fwiw, dunk sparging in your fermenter may not be the best practice. The preboil wort is not sanitary, so you are contaminating your fermenter. Yes, I realize it gets sanitized, it's just best practice not to use the same equipment pre and post boil.

compared to whatever might float into it while it's stored in the shed....i'll take that small risk I do wash and sanitize it afterward.

 

[pricelessbrewing]

I've done that as well. Imo the threat of contamination/infection from your fermenter is pretty low. Michael tonsmiere aka the mad fermentationist uses the same fermenter for his mixed microbe fermentations and his pure sacc brews. He's had two infections ever, only one of which he think a could've been the fermenter.

 

[doug293cz]

Here's the efficiency story for no sparge BIAB. The data is for 100% conversion and 6.75 gal pre-boil volume (corrected to 68°F). Strike volume is adjusted for grain absorption to get a constant pre-boil volume. Grains are assumed to have 80% by weight conversion potential on a dry basis, and 4% moisture ("as is" conversion potential of 76.8%)



Grain absorption is affected by how long you drain and/or how well you squeeze. If your conversion percentage and your grain absorption (gal/lb) are consistent, then your efficiency will be consistent and depend only on your grain bill.

Brew on

 

[doug293cz]

The conversion may happen in any case if moisture of the right temperature can make it's way into the particle, but a finer crush will better allow those sugars to be released from the particle, rather than remain inside of it.

Actually, the rate limiting step (at least for larger grain particles) is getting the water into the particles for gelatinization to occur, not getting the sugar to "release" from the particles. Gelatinization occurs in layers from the outside of the particle towards the center. After gelatinization has occurred, the starch is soluble and goes into solution. Most of the actual conversion takes place in the liquid and gelatinized layers on the outer edges of the particles.

Brew on

 

[doug293cz]

... If there is no good reason to go with 1.25:1 ratio, then why is it taught?

...

Primarily because significantly thicker mashes are harder to stir and get good mash in, and significantly thinner mashes don't leave enough needed volume to get a good sparge. People used to think that thicker mashes converted better due to higher enzyme concentrations, but this has been debunked experimentally (and theoretically.) So, for fly spargers, ~1.25 qt/lb gave a good compromise between ease of mashing, and allowing for a large enough sparge volume for good efficiency.

The 1.25 ratio initially was carried over into batch sparging, until folks learned that thinner mashes convert more efficiently. Batch sparging recommendations are now to target strike and sparge volumes for equal run-off volumes.

Brew on

 

[doug293cz]

Although in theory this is true, in practice a 30-60 minute mash is long enough to get full conversion regardless of particle size. If I remember Braukaiser's experiments, under most "normal" conditions, one can assume near complete conversion efficiency (upwards of 90% anyway) and therefore the lauter should be targeted if you are looking for improvements in efficiency.

In short, the rate limiting step is the lauter.

I disagree. There have been several threads recently started by brewers with poor efficiencies. I have done analysis of the conversion and lauter efficiencies in for many of these brewers processes (and posted the results in their threads.) The biggest detractor is usually (but not always) low conversion efficiency. There might be some loss of lauter efficiency, but it's not the big hitter.

Brew on

 

[broadbill]

I disagree. There have been several threads recently started by brewers with poor efficiencies. I have done analysis of the conversion and lauter efficiencies in for many of these brewers processes (and posted the results in their threads.) The biggest detractor is usually (but not always) low conversion efficiency. There might be some loss of lauter efficiency, but it's not the big hitter.

Brew on

I'd be interested to see how you do this, as I don't see how this is possible without directly testing samples from that person's setup.

 

[Homercidal]

Actually, the rate limiting step (at least for larger grain particles) is getting the water into the particles for gelatinization to occur, not getting the sugar to "release" from the particles. Gelatinization occurs in layers from the outside of the particle towards the center. After gelatinization has occurred, the starch is soluble and goes into solution. Most of the actual conversion takes place in the liquid and gelatinized layers on the outer edges of the particles.

Brew on

Interesting. So does a mash stir help the starches release from the grain particle after gelatinization? I am trying to visualize this, but I can only see that the starches might still be bound up in the protein and other things that make up the part of the kernel that is converted.

I've wanted to make animated brewing videos describing how the process works, and this would be a perfect example of how an animated visual would be useful. I need to learn how to do simple animations.

 

[pricelessbrewing]

I'd be interested to see how you do this, as I don't see how this is possible without directly testing samples from that person's setup.

If you know the grain bill, and the water volumes, then you can estimate the conversion efficiency based on the run off volume and gravity. You can then estimate the lauter efficiency based on the total run off (and and subsequent sparge volumes)

Doug sent me his batch sparge simulator, and it seems to be accurate. The one time I had a higher gravity for my 2nd run off, but that was due to the grain not being drained fully before adding my sparge volumes. (it was biab so technically I lifted the grain bag and it wasn't down draining before I dunk sparged)

 

[doug293cz]

Interesting. So does a mash stir help the starches release from the grain particle after gelatinization? I am trying to visualize this, but I can only see that the starches might still be bound up in the protein and other things that make up the part of the kernel that is converted.

I've wanted to make animated brewing videos describing how the process works, and this would be a perfect example of how an animated visual would be useful. I need to learn how to do simple animations.

Yes, mash stirring or recirculation will help the swelled starch coating the particles to slough off and go into solution faster.

I was thinking after writing this post that putting a couple of different size malt particles under a microscope during gelatinization would make a good video. The hard part of making the video would be devising a way to heat a small volume of water on the microscope stage to a controlled temperature. A "micro mash tun" if you will.

Brew on

 

[doug293cz]

I'd be interested to see how you do this, as I don't see how this is possible without directly testing samples from that person's setup.

With suitable data from a brew session, it's possible to model the lauter process for batch (or no) sparge with reasonable accuracy. If their batch sparging process is reasonable as far as agitation and timing, then it's difficult to get results very different from the model. Once you have an estimated lauter efficiency, you just divide the mash efficiency by the lauter efficiency to get the conversion efficiency. The data used includes:

• Grain bill (just total weight is usually enough)
• Strike water volume
• Sparge water volume
• Pre-boil volume
• Pre-boil specific gravity

Additional data on first runnings gravity, first runnings volume, etc. can aid with doing consistency checks on the model.

The efficiency calculations are based on a mass balance of all of the sugar and water thru all the run-off steps.

Here's a link to a thread where the brewer had both conversion and lauter efficiency issues: https://www.homebrewtalk.com/showpost.php?p=7171152&postcount=19

And here's a thread where the problem is mostly poor conversion efficiency: https://www.homebrewtalk.com/showpost.php?p=7161662&postcount=13

Brew on

 

[doug293cz]

Here's the efficiency story for no sparge BIAB. The data is for 100% conversion and 6.75 gal pre-boil volume (corrected to 68°F). Strike volume is adjusted for grain absorption to get a constant pre-boil volume. Grains are assumed to have 80% by weight conversion potential on a dry basis, and 4% moisture ("as is" conversion potential of 76.8%)

View attachment 312526

Grain absorption is affected by how long you drain and/or how well you squeeze. If your conversion percentage and your grain absorption (gal/lb) are consistent, then your efficiency will be consistent and depend only on your grain bill.

Brew on

Thought I'd drop the other shoe, and compare no sparge vs. single sparge with equal runnings. For the sparge process a dunk sparge with stirring is assumed, and the grain absorption is the same for initial drain and sparge drain (have to drain/squeeze both steps the same amount.) Other conditions are the same as the quoted post.



Brew on

 

[PlexVector]

Yes, mash stirring or recirculation will help the swelled starch coating the particles to slough off and go into solution faster.

I was thinking after writing this post that putting a couple of different size malt particles under a microscope during gelatinization would make a good video. The hard part of making the video would be devising a way to heat a small volume of water on the microscope stage to a controlled temperature. A "micro mash tun" if you will.

Brew on

A micro-mash tun could be made with a coil of NiChrome wire on a slide. Use silicone adhesive to keep the shape. Solder a thermister to it and create a feedback system to control the temp of the wire.

 

[doug293cz]

A micro-mash tun could be made with a coil of NiChrome wire on a slide. Use silicone adhesive to keep the shape. Solder a thermister to it and create a feedback system to control the temp of the wire.

Something like that should work. The short thermal time constant of such a micro mash tun would require a fast acting controller in order to keep a stable temperature. The kinds of PID's used by homebrewers for their macro mash tuns wouldn't cut it.

Brew on

 

[hafmpty]

More dilute mashes seem to perform numerically better all else being equal.

Contrary to common believe no attenuation difference was seen between a thick mash (2.57 l/kg or 1.21 qt/lb) and a thin mash (5 l/kg or 2.37 qt/lb).

This ratio is quite a bit lower than typical BIAB brewing though. So in actuality we are comparing thin mashes to VERY thin mashes, right?

 

[PlexVector]

Something like that should work. The short thermal time constant of such a micro mash tun would require a fast acting controller in order to keep a stable temperature. The kinds of PID's used by homebrewers for their macro mash tuns wouldn't cut it.

Brew on

A DC PWM controlled by a microcontroller driving a power mosfet would be the easiest and safest.

 

[castillo556]

I often use my fermenting bucket for the sparge dunk, easy to just drop a few gallons of water in that i boiled with an electric kettle.

I do as well, simple and effective.

 

[doug293cz]

This ratio is quite a bit lower than typical BIAB brewing though. So in actuality we are comparing thin mashes to VERY thin mashes, right?

Depends on the grain bill. Typical full volume BIAB ratios (assuming 6.75 gal pre-boil, 5.5 gal post-boil, 0.08 gal/lb grain absorption, and 95% conversion efficiency) would range from:

~4.18 qt/lb for 7 lb of malt yielding an OG of ~1.038​

to

~1.45 qt/lb for 24 lb of malt yielding an OG of ~1.100​

For a 2.37 qt/lb ratio you would use about 13 lbs of malt to yield an OG of about 1.064.

Brew on