BIAB: Dunk Sparge!

[NeoBrew]

I've got a few BIAB batches under my belt now with great results. On my last batch I went from hang and squeeze to a dunk sparge in about 1 1/2 gallon of water at mash out temps (168F).

I have to say, I'm never going back!

I set the grain bag in my 4 gallon pot, swished it around a bit with a metal spoon. I watched the sugary goodness seep into the water.

I did let the bag hang over the pot while heated up to the boil. I used to spend a lot of time squeezing that bag with a lid and my stir spoon to try to get that really sweet stuff out. I couldn't stand to let that wort go, so I left it there well into the boil. With the dunk sparge all that was coming out was pretty clear almost tasteless liquid. By the time I hit boil I set the bag aside out of the way.

Beersmith had me at 87% efficiency. I way overshot my numbers because I had gotten 63% last time and upped my grain bill to compensate. I have had worse problems!

The extra pot of water is more complicated, I know. But it's totally worth it for me.

 

[BigRock947]

Gotta love those ah ha moments....when i did 2.5 gallon and 5 gallon batches that was the only way i could enough wort with my two smaller pots.

Congrats on the higher efficiency....i went from 70 to 80% efficiency myself.

 

[FatDragon]

I usually do a cold dunk or pourover sparge with the bag in a grain bucket. Let it soak for about ten minutes, toss the sparge water in the BK, then I've got a much more squeezable bag to deal with. At the same time, I don't have a hoist yet, so I don't have the option of dangling the bag and squeezing with pot lids that would absorb a lot of the heat.

 

[MikePote]

I do the exact same thing and love it. Please post your efficiency after your next brew. I get 70-75% consistently but 87% is stupid. Im curious if you will get this consistently. I put the grains in a colander on top of my boil/mash kettle and smash them with a potato masher. Not sure if it actually helps but it makes me feel like im getting the most sugars out.

 

[DaNewf]

I use two pots and a fermenter for my mashing/sparging/boiling process.

I mash in a 19l pot and use a 12l pot for sparge water. I guess I would call my sparge method batch sparging. I drain the 19l pot into the fermenter and then (after putting the grain back in) refill with water from the 12l pot. Stir and wait 10-15 minutes. Then I drain the 19lpot pot and do a second sparging. After dumping the second sparge I'm pretty close to boil volume in the fermenter. Then I do a squeeze step. I put a colander over the 12l pot and use a dinner plate to squat the grain out. Squeezings go into the fermenter. If I am still a little shy of my boil volume I'll rinse the grains and squat again.

I'll then give the fermenter a gentle stir and drain the wort into both (19l and 12l) pots. These go on my electric stovetop to boil.

This method is a little more tedious but it allows me to do full 5 gallon batches in my kitchen without having to buy any extra equipment and without having to do high gravity wort with post boil dilutions. I had the 19l already for doing mini mash brewing and the 12l pot is my wife's soup/stock pot. I don't need to buy a larger pot to do the boil in one vessel and none of the burners on my stovetop would be able to bring that that much liquid to a boil anyway.

I don't know what efficiency I'm getting but I get pretty close to expected OG (usually a little higher).

 

[dobe12]

I do the same thing and routinely hit 80-85% efficiency with an average grain bill. I mash somewhere between 1.5 and 2.0qt/lb and get enough of a sparge to collect close to equal runnings from the mash and sparge.... or at least within a gallon or so of each other. I'm usually somewhere around 60% preboil is from the mash and 40% from sparge.

With a smaller grain bill (8-10lbs) I've hit 88%.
With 12-14lbs I hit 80-85%.
This past weekend I mashed 18lbs and hit 71%.

One other large factor is my crush. I mill my own grain and since I BIAB, I crush a little finer. That really helps with efficiency.

Last summer I tried a few full volume mashes and my efficiency dropped into the 60's. I quickly went back to the dunk sparge. It only adds 5-10 minutes to my brew day and maybe 2-3 extra minutes to wash the second pot, but well worth the spike in efficiency.

 

[PRE66_6TART]

Yep, I dunk sparge and love it. I hate squeezing the bag. I like your description of watching all the sugary goodness seeping out into the water. I just dunk my bag up and down like a tea bag rather than stirring though. I do that for a few minutes and I'm done.

I used to use cold water so the bag was less hot when I squeezed it, but now I gave up on the squeezing, so I just heat all my water up in my boil kettle, and then syphon some out into my 5 gallon mash kettle with the grains in it until it's full and leave whatever is left for the dunk sparge.

 

[BlueHouseBrewhaus]

I started out around 65% with my first BIABs. Then after a few brews I started double crushing my grains and got 70%. Then I increased my mash time from 60 min to 75 min and got 75%. I tried doing a dunk sparge but got inconsistent results.

More recently, I started reserving about 8 - 10 qts from my mash and mashout water and I do a very slow "trickle batch sparge" through the raised grain bag for about 30 min. This gets me around 80 - 82%. To simplify the sparge (and save my arms) I cut off the bottom third of a Home Depot bucket and put several tiny holes in the bottom. With some trial and error I was able to figure out how many holes it took to release 8 qts over 30 min. Now I can just rest the sparge bucket in the top of the fryer basket that holds my grain bag and pour in the sparge water. Sit back and wait for the water to trickle through. Works great. I think I'm about at my efficiency limit but I'm happy with it.

 

[RM-MN]

I started out around 65% with my first BIABs. Then after a few brews I started double crushing my grains and got 70%. Then I increased my mash time from 60 min to 75 min and got 75%. I tried doing a dunk sparge but got inconsistent results.

More recently, I started reserving about 8 - 10 qts from my mash and mashout water and I do a very slow "trickle batch sparge" through the raised grain bag for about 30 min. This gets me around 80 - 82%. To simplify the sparge (and save my arms) I cut off the bottom third of a Home Depot bucket and put several tiny holes in the bottom. With some trial and error I was able to figure out how many holes it took to release 8 qts over 30 min. Now I can just rest the sparge bucket in the top of the fryer basket that holds my grain bag and pour in the sparge water. Sit back and wait for the water to trickle through. Works great. I think I'm about at my efficiency limit but I'm happy with it.

To me the increased efficiency with increase time says that even double crushed your grains are not milled fine enough. Tighten the gap on the mill, double crush again and see if you get the same results. I can get over 80% efficiency with a 10 minute mash.

 

[BlueHouseBrewhaus]

It's actually my LHBS's mill so I don't have the option of changing the settings. But maybe I'll try triple crushing! The funny thing is that when I have done a 60 or 45 min mash, I test and show full conversion. But I still get higher efficiency with a longer mash. Not sure why that is. Is there such thing as "good" conversion and "really good" conversion?

 

[RM-MN]

When you test for conversion, are you getting wort or mostly grains. The grains are where you need to test for conversion.

I bought a cheap Corona mill knock off and use that to mill my grains. I have it set as tight as I can.

 

[BlueHouseBrewhaus]

It's typically a spoonful of mixed grain and wort. Early on I deliberately tested for conversion when I knew it hadn't yet fully converted just to be sure I was testing correctly. I have seen conversion as early as 15 or 20 minutes but I still see my efficiency improve with a longer mash. Once I get past 75 minutes I don't see any more increase. I've never really questioned it but assumed there must be some explanation I just wasn't aware of. As long as it works I don't really care but I am a little curious.

 

[wilserbrewer]

Back on topic of dunk sparing the grain bag, I have done it, and it works well.

Recently I have been practicing a pour over sparge withe the grain bag hanging over the kettle, perhaps not quite as efficient, but much easier...I like easy btw.

The added benefit of the pour over sparge is that you simply sparge to your pre boil volume. Basically I just eyeball the main mash strike water volume, them fine tune with the pour over sparge to hit PB volume. No calculators, no measuring just RDWHAHB and all is good.

Typical sparge is about a gallon on a 1/4 keg, 8 gallon batch.

 

[BlueHouseBrewhaus]

Sorry for straying off topic but, yes, I have had better luck with my 8 - 10 quart "trickle sparge". The dunk sparge sometimes seemed to improve my efficiency and sometimes didn't - varied from 72-78%. My LHBS guy said the secret was to sparge as slooowwwwly as humanly possible. At first I just used a measuring cup to drizzle over the raised grain bag. I aimed for about 3 minutes to empty a 1 qt measuring cup. That was tiring on the arm. So then I created my previously described sparge bucket. Since I hang my grain bag in a turkey fryer basket, this bucket rests nicely in the top of the basket. Still fine tuning but I consistently get 80-82% efficiency.

 

[NeoBrew]

Another good day for my dunk sparge. Beersmith said 78% mash efficiency, 93% brew house efficiency. I measured the gap in my captain crush. I'm running about 60 on the upper roller and 30 on the lower. I'm also running it through twice. It's pretty fine after that. I actually had to massage the bag a bit when I first pulled it to get it draining well.

Should I worry about being too efficient?


Sent from my iPad using Home Brew

 

[Christopher Darkly]

To me the increased efficiency with increase time says that even double crushed your grains are not milled fine enough. Tighten the gap on the mill, double crush again and see if you get the same results. I can get over 80% efficiency with a 10 minute mash.

Damn, that's impressive. I have my mill set to the minimum which is 0.018 inches (measured with feeler gauges) and I double crush and still only get 70%. BUt I'm going to try the trickle drip sparge. Running the grinder that tight puts a serious load on my drill and it's a Hitachi hammer drill that can put holes in concrete all day long.