Dunk Sparge...

[Mike at Bay]

I BIAB. Now after several brews I am looking for ways to increase efficiency and get more predictable results. I am considering a Dunk Sparge. If I understand this process correctly it would be essentially

o-putting say 2 gallons of cooler water into a separate vessel,
o-reduce my primary kettle mash volume to account for the 2 gallon sparge to be added later,
o-once normal mash in bag is complete move the bag over to the dunk sparge vessel,
o-Stir grains in the sparge vessel for a bit,
o-Raise bag and squeeze,
o-add sparge water to primary kettle and carry on.

I have also started double milling my grains which seems to help.

The seems to be conflicting opinions as to whether the Dunk Sparge step is worth it. Thoughts?

 

[Megary]

In my opinion, it’s not worth it. If you reduce your regular mash volume to accommodate for the sparge volume you are going to lose efficiency in the main mash. The lower the ratio of water:grain in the main mash, the worse the efficiency*. Anything gained back by a sparge is only going to put you right back to what you would have had from a full volume mash. And a sparge is a pain in the ass.
Others may disagree, but that’s what I found with BIAB on my stove.

Set your rollers to crush very fine, mash for 60-90 minutes…and relax. Chasing efficiency is not that important. Being consistent and predictable is.

* If you full volume BIAB, you might consider a rolling scale of efficiency based on the amount of grains in the mash. For smaller beers (say 1.040 or so), I’ll get much better efficiency than bigger beers (1.065). So for the smaller beers, I might set my recipe efficiency at 80%, and for the bigger beers…72%. Really big Barleywines or Imperial Stouts, my efficiency is more like 65-68%. That is simply a product of water:grain ratio and the nature of full volume BIAB brewing.

Good luck.

 

[Brew Cat]

Well totally disagree
I dunk sparge and am getting 85%
I don't double crush
I crush once at .027
Mash with about 4gal
1.5 quarts per pound
A thick mash increases efficiency
Stir the mash at least once at about 30min
After my full mash time I stir pull and squeeze
I then drop the bag in the boiled water dunk sparge stir and squeeze some more
I've done full volume and get descent efficiency as well
The sparge gives me about 5% more
I'm assuming you're adjusting the water ph

 

[Brew Cat]

I BIAB. Now after several brews I am looking for ways to increase efficiency and get more predictable results. I am considering a Dunk Sparge. If I understand this process correctly it would be essentially

o-putting say 2 gallons of cooler water into a separate vessel,
o-reduce my primary kettle mash volume to account for the 2 gallon sparge to be added later,
o-once normal mash in bag is complete move the bag over to the dunk sparge vessel,
o-Stir grains in the sparge vessel for a bit,
o-Raise bag and squeeze,
o-add sparge water to primary kettle and carry on.

I have also started double milling my grains which seems to help.

The seems to be conflicting opinions as to whether the Dunk Sparge step is worth it. Thoughts?

Sparge with hot water

 

[Megary]

A thick mash increases efficiency

Interesting. Completely opposite of what happens in my kitchen. Gotta love this hobby.

 

[Mike at Bay]

Thanks. Yes adjusting the PH. I honestly felt the sparging would add a step and time to the process and questioned the value. I may try it a few times and see what happens compared to not do it. I lean towards not do it but the data will be valuable.

 

[Brew Cat]

Thanks. Yes adjusting the PH. I honestly felt the sparging would add a step and time to the process and questioned the value. I may try it a few times and see what happens compared to not do it. I lean towards not do it but the data will be valuable.

I've actually had good luck just holding back some water
And boil and dump it on top of the mash like a mash out
I think the key is squeeze the bgesus out of the bag
Leave nothing behind and still get your exact volume

 

[Brew Cat]

Interesting. Completely opposite of what happens in my kitchen. Gotta love this hobby.

What the mash thickness or the dunk sparge?
As always volume is important you need to end up getting back your water
If you don't squeeze a full volume BIAB your never going to read good efficiency

 

[Mike at Bay]

What the mash thickness or the dunk sparge?
As always volume is important you need to end up getting back your water
If you don't squeeze a full volume BIAB your never going to read good efficiency

I am big on the squeeze.

 

[Herm brews]

Stovetop BIAB full volume mash is my process using a 5.5 gallon kettle for 2.75 gallons into the fermenter. My mill gap is set at .025, and the grains get run through twice. Because I enjoy data collection, I stir and measure temperature while collecting a refractometer sample at 20 minute intervals through 80 minutes of mashing. After the mash, I remove the grain bag and let it drain through a collander into another pot, adding that liquid to the kettle for the boil. In the end, I am usually within a point or two of projections, using 75% efficiency for my recipes.

 

[Brew Cat]

Stovetop BIAB full volume mash is my process using a 5.5 gallon kettle for 2.75 gallons into the fermenter. My mill gap is set at .025, and the grains get run through twice. Because I enjoy data collection, I stir and measure temperature while collecting a refractometer sample at 20 minute intervals through 80 minutes of mashing. After the mash, I remove the grain bag and let it drain through a collander into another pot, adding that liquid to the kettle for the boil. In the end, I am usually within a point or two of projections, using 75% efficiency for my recipes.

75% is fine anything less and I would look at my process
I never do an 80 minute mash except maybe a decoction
What's your efficiency at 60 ? Or you counting mash in and draining as your mash time?
When I talk mash time I'm talking about the rest
Of course unless you're doing a mash out your still mashing until your wort is above 175F really

 

[BarbarianBrewer]

Thanks. Yes adjusting the PH. I honestly felt the sparging would add a step and time to the process and questioned the value. I may try it a few times and see what happens compared to not do it. I lean towards not do it but the data will be valuable.

This would be my advice. I do all-grain batch sparge in a picnic cooler (not BIAB). In the beginning, there were similar "is it worth it" discussions on whether to batch sparge once or twice. I found that the first sparge added a significant amount of sugars to the kettle. But the 2nd sparge added some sugars, but not enough to be worth the effort.

A thick mash increases efficiency

Interesting. Completely opposite of what happens in my kitchen. Gotta love this hobby.

I found better efficiency mashing on the thinner side (1.8qt/lb). But I found the below in my notes which, as with most things in home brewing, shows that there are pros and cons to everything.

This is directly out of HOW TO BREW by John Palmer:
The grist/water ratio is another factor influencing the performance of the mash. A thinner mash of >2 quarts of water per pound of grain dilutes the relative concentration of the enzymes, slowing the conversion, but ultimately leads to a more fermentable mash because the enzymes are not inhibited by a high concentration of sugars. A stiff mash of <1.25 quarts of water per pound is better for protein breakdown, and results in a faster overall starch conversion, but the resultant sugars are less fermentable and will result in a sweeter, maltier beer. A thicker mash is more gentle to the enzymes because of the lower heat capacity of grain compared to water. A thick mash is better for multirest mashes because the enzymes are not denatured as quickly by a rise in temperature.

 

[Megary]

What the mash thickness or the dunk sparge?
As always volume is important you need to end up getting back your water
If you don't squeeze a full volume BIAB your never going to read good efficiency

I always full volume mash so my water is right there. I'll squeeze the bag until I hit my pre-boil volume and that's that. Very simple process.
All I'm saying is that the more grain that goes in the kettle, the lower the water:grist ratio, the worse my efficiency. The conversion efficiency difference is negligible over small gravity ranges, but is noticeable when comparing a 1.040 beer to a 1.065 beer to a 1.095 beer.

If I were to withhold some of my mash water to rinse the grains post-mash then my main mash efficiency would suffer (lower water:grist). Sure, I'd get a boost from rinsing but it would only bring me back to where I would have been had I just used all of the water in the main mash to begin with. I personally don't see the point of rinsing with BIAB unless your kettle isn't large enough to mash with the full volume of water to begin with. Again, that's just my opinion.

Cheers!

 

[Brew Cat]

I always full volume mash so my water is right there. I'll squeeze the bag until I hit my pre-boil volume and that's that. Very simple process.
All I'm saying is that the more grain that goes in the kettle, the lower the water:grist ratio, the worse my efficiency. The conversion efficiency difference is negligible over small gravity ranges, but is noticeable when comparing a 1.040 beer to a 1.065 beer to a 1.095 beer.

If I were to withhold some of my mash water to rinse the grains post-mash then my main mash efficiency would suffer (lower water:grist). Sure, I'd get a boost from rinsing but it would only bring me back to where I would have been had I just used all of the water in the main mash to begin with. I personally don't see the point of rinsing with BIAB unless your kettle isn't large enough to mash with the full volume of water to begin with. Again, that's just my opinion.

dial in your water so there is nothing left after you squeeze
like I mentioned above volume
if your leaving water your leaving sugars
hey I do it both ways and if I'm being lazy I use my AIO and full volume
my point is even then Im getting 80% I calculate 6.5 to the kettle and after squeezing every drop of liquid I have exactly 6.5 gallons
I only gain a bit more from the sparge but always the exact same amount of water
maybe its getting the bit of sugar stuck to the grains
When I do a multi step or decoction I really pull out more efficiency and sometimes end up adding a bit of extra water to knock it down

efficiency doesn't matter anyway as long as you can get the same or close all the time for recipe design purposes
I'm just cheap and don't want to use more grain than I need to

 

[Herm brews]

75% is fine anything less and I would look at my process
I never do an 80 minute mash except maybe a decoction
What's your efficiency at 60 ? Or you counting mash in and draining as your mash time?
When I talk mash time I'm talking about the rest
Of course unless you're doing a mash out your still mashing until your wort is above 175F really

My mash time is started after I have poured in the crushed grains, stirred thoroughly to ensure there are no clumps, measured the temp, then put the lid in place. My mash time ends when 80 minutes of rest time has passed. At that point, I lift the grain bag and let it drain until flow reduces to drips, then put the bag in the collander to drain over a spare pot. After collecting as much wort as possible, I stir that thoroughly and I collect a pre boil gravity sample. So in reality, my mash is probably closer to 90 minutes, but I have wort at or within a point or two of projections and my volume is on target. In that extra 20-30 minutes, I pick up sometimes nothing, other times as much as 3 gravity points. My process works for me, and I hope your’s works well for you.

 

[Brew Cat]

Everyone has their system and that's fine
The OP was asking if he can tweak out some more efficiently I'm offering him suggestions don't mean for anyone else to change their techniques

My mash time is started after I have poured in the crushed grains, stirred thoroughly to ensure there are no clumps, measured the temp, then put the lid in place. My mash time ends when 80 minutes of rest time has passed. At that point, I lift the grain bag and let it drain until flow reduces to drips, then put the bag in the collander to drain over a spare pot. After collecting as much wort as possible, I stir that thoroughly and I collect a pre boil gravity sample. So in reality, my mash is probably closer to 90 minutes, but I have wort at or within a point or two of projections and my volume is on target. In that extra 20-30 minutes, I pick up sometimes nothing, other times as much as 3 gravity points. My process works for me, and I hope your’s works well for you.

 

[Mont Y. Märzen]

Interesting. Completely opposite of what happens in my kitchen. Gotta love this hobby.

Braukaiser disproved it as well. Thinner mashes are more efficient likely due to the greater contact and absorption. Thicker mashes reach a saturation point that full-volume does not. Hence, one of the reasons for a sparge step in thick mashes. (the other being lack of tun capacity for full-volume which generally requires double the final batch size for total volume+ a spill factor during the boil.)

 

[Mont Y. Märzen]

I BIAB. Now after several brews I am looking for ways to increase efficiency and get more predictable results. I am considering a Dunk Sparge. If I understand this process correctly it would be essentially

o-putting say 2 gallons of cooler water into a separate vessel,
o-reduce my primary kettle mash volume to account for the 2 gallon sparge to be added later,
o-once normal mash in bag is complete move the bag over to the dunk sparge vessel,
o-Stir grains in the sparge vessel for a bit,
o-Raise bag and squeeze,
o-add sparge water to primary kettle and carry on.

I have also started double milling my grains which seems to help.

The seems to be conflicting opinions as to whether the Dunk Sparge step is worth it. Thoughts?

Can you recirculate with a pump?

If not, a pitcher will still work, just slower and more cumbersome.

I raise my bag for mash-out, get the wort to 168℉ and 'rinse' the grain bag with the wamer, and now thinner, wort for about 10 minutes. This buys me 5 SG points vs. not doing it. I do not add any fresh water and maintain tight temp control, so there are no pH or temp issues extracting tannins as might be possible using fresh water with a sparge. (can still be controlled for of course)

You might find that much easier. Volumes are not affected.

Finally, I would not bother chasing efficiency improvements until very meticulously dialing-in a system, particularly with respect to measuring (not estimating) volumes. Once you know them, you can estimate a bit, but even a small estimation can throw off efficiency calculations 5% or more. Get really good at consistently hitting volumes, *then* perhaps look at places you can cut losses. (the cause of inefficiency) Also, be sure you are not mashing by time, but to 100% conversion. Use an Iodine test to confirm, don't just go by recipe estimates and readings. If you end a mash too early, you're already leaving some SG points behind. The rest will be lost at various points in the system.

 

[Brew Cat]

Can you recirculate with a pump?

If not, a pitcher will still work, just slower and more cumbersome.

I raise my bag for mash-out, get the wort to 168℉ and 'rinse' the grain bag with the wamer, and now thinner, wort for about 10 minutes. This buys me 5 SG points vs. not doing it. I do not add any fresh water and maintain tight temp control, so there are no pH or temp issues extracting tannins as might be possible using fresh water with a sparge. (can still be controlled for of course)

You might find that much easier. Volumes are not affected.

Finally, I would not bother chasing efficiency improvements until very meticulously dialing-in a system, particularly with respect to measuring (not estimating) volumes. Once you know them, you can estimate a bit, but even a small estimation can throw off efficiency calculations 5% or more. Get really good at consistently hitting volumes, *then* perhaps look at places you can cut losses. (the cause of inefficiency) Also, be sure you are not mashing by time, but to 100% conversion. Use an Iodine test to confirm, don't just go by recipe estimates and readings. If you end a mash too early, you're already leaving some SG points behind. The rest will be lost at various points in the system.

probably why the sparge method increases efficiency is because of the extra stirring
and by the way 10 lbs of grain in 4 gallons of water is not exactly a thick mash and probably the difference in enzyme activity compared to full volume is fly poop
if you step mash and add water at 30 or 40 minuets and stir you'll bump efficiency more
again probably the stirring
I don't usually do a dunk sparge but do do step mashing and like I said 80 -90%
that said efficiency doesn't matter consistency does

 

[Ozarks Mountain Brewery]

for people wanting more efficiency you could just add more base grain, it does the same thing