Highest efficiency with dunk sparging

[tempestam83]

Been brewing BIAB for about 6 batches now. Have been doing a 3-gallon boil with 2-gallon pour over sparge at 170. I've been getting 50-60% efficiency until today.

Tried my first dunk sparge making a Zombie Dust clone and got to 72% efficiency. Very pleased with the result.

Did the same 3-gallon boil and 2-gallon sparge but this time when the mash was up, I transferred the grains to a bucket and poured the sparge water in with it, covered it and let it sit for 10 minutes before pouring it back in the kettle.

Simple enough.

Any one else use this method?

 

[IslandLizard]

Yeah, it's remarkable, huh?

The fluid dynamics of a pour over are crappy as can be. A good squeeze instead, will yield more.
You should really get way above 80% with your BIAB system. Get a finer crush!

When the bag is in your dunk bucket, you need to stir it well too, to rinse the sugars out of the grains.

 

[slym2none]

Very nice indeed!

I agree with m00ps, a finer crush will get you over 80%, more than likely. My LHBS is, like most others, caught between needing a crush that works for three-tiered systems & for BIAB'ers. Even running it through twice (which is the best they can do for us that BIAB) leaves lots of kernels that, while crushed/cracked, are still whole. I am getting about 75% out of that crush, using a 75-minute mash. If I ever get my own mill, I imagine a 5-point jump will happen.

 

[IslandLizard]

Very nice indeed!

I agree with m00ps, a finer crush will get you over 80%, more than likely. My LHBS is, like most others, caught between needing a crush that works for three-tiered systems & for BIAB'ers. Even running it through twice (which is the best they can do for us that BIAB) leaves lots of kernels that, while crushed/cracked, are still whole. I am getting about 75% out of that crush, using a 75-minute mash. If I ever get my own mill, I imagine a 5-point jump will happen.

"Run through twice" is another one of so many myths that keep hanging around, like bad voodoo. Another one is the "CO2 blanket" after lifting the lid.

You could get a Corona knock off for $25 and run them through that after your LHBS did their job. Or get a decent 2-roller some day. Buying grain in bulk will also earn back your mill over time.

Small kernels like wheat and rye never get crushed on a wide gap. I had a wheat ale from someone and I kept asking, are you sure it's a wheat? Guess why?

BTW, I'm not m00ps...

 

[pricelessbrewing]

I would recommend stirring the dunk sparge instead of just letting it rest.

Pull grain bag, squeeze, dunk grain bag into the batch sparge volume, open bag, stir the crap out of it for several minutes, pull bag, squeeze. Combine runnings. Enjoy the lauter efficiency boost.

 

[jtratcliff]

I would recommend stirring the dunk sparge instead of just letting it rest.

Pull grain bag, squeeze, dunk grain bag into the batch sparge volume, open bag, stir the crap out of it for several minutes, pull bag, squeeze. Combine runnings. Enjoy the lauter efficiency boost.

This!

 

[wilserbrewer]

I would recommend stirring the dunk sparge instead of just letting it rest.

Pull grain bag, squeeze, dunk grain bag into the batch sparge volume, open bag, stir the crap out of it for several minutes, pull bag, squeeze. Combine runnings. Enjoy the lauter efficiency boost.

Yes agreed, stirring thoroughly will help to rinse the grain while dunk sparging.

While you can do this and enjoy the higher efficiency, you can also throw another $1 worth of grain in the mash and enjoy the ease and simplicity of full volume brewing. Neither right or wrong or better process, just a choice one can make.

 

[tempestam83]

All great advice! Will try out on my next brew day. Unfortunately I'm going on vacation in Miami and won't be able to brew. Very frustrated.

 

[Desertbrewer]

Does the dunk water need to 170, or is the temperature less relevant because the grain has converted starch to sugar already?

 

[dmtaylor]

I just got 81% brewhouse efficiency on my last dunk sparge. In the past I used to get >90% but I realized this had an adverse effect on malt flavor in the finished beer, so I actually opened the gap slightly on my mill, and think I'll keep it here now. Low 80s seems a good tradeoff between wasting malt (when efficiency is too low) and not having sufficient malt flavor and body (when efficiency is too high).

Oh... and by the way..... I only ever mash for 40-45 minutes. Any longer than that is a waste of time for most styles, except maybe for saison, etc.

 

[RM-MN]

Does the dunk water need to 170, or is the temperature less relevant because the grain has converted starch to sugar already?

You can use cold water for the sparge, dunk or pour over. The hot, wet grains will raise the temperature of the sparge water anyway so your sugars are easily rinsed out.

 

[dmtaylor]

Does the dunk water need to 170, or is the temperature less relevant because the grain has converted starch to sugar already?

I calculate the temperature that will make it hit 170 F. It's usually right around 190 F. It makes sense too because when you blend together something at 150 F and 190 F, it will even out to around 170 F. Perfect. But getting that fancy isn't even necessary as others have and will mention. Any rinsing of the grains with any temperature of water is going to give you a big efficiency boost. Also mashouts are unnecessary unless you plan to leave your wort sitting around for hours. If you're going to bring it to a boil in a few minutes anyway, then mashout temperature is irrelevant because you'll hit it soon enough regardless.