How much does (continuously) stirring and circulating the mash increase efficiency ?

[brewman !]

I'm wondering what role stirring and circulating the mash plays in mash efficiency.

How much difference in efficiency will the following have, assuming a well insulated mash tun.

1) Stagnant mash, ie not circulated or stirred.

2) A stirred mash, where one periodically stirs the mash.

3) A circulated mash, where a pump is continually moving the liquid portion of the mash.

4) A continuously stirred mash, where a rake is continually mixing the mash.

5) A continuously stirred and circulated mash.

Can one get 80% efficiency with a stagnant mash ? Does circulating the mash liquid significantly decrease mash temperature gradients or otherwise somehow improve extraction ? How does stirring the mash compare with circulating the mash ?

Thanks

 

[Dland]

Usually I stir when I mash in to make sure there are no dough balls. If there water is added for temp step or adjustment, I'll stir then too. Otherwise, I do a 10 Min recirulaltion at end of mash to settle in grain bed, then fly sparge w fairly hot water.

I just got 85% efficiency doing above today, with only the stir at mash in.

 

[dmtaylor]

I've gotten up to mid-90s efficiency with a stagnant mash. Crush matters more than anything. Stirring and fiddling around isn't necessary. A really good crush IS necessary, IF maximizing efficiency is a goal (and no, it doesn't have to be).

 

[Big Monk]

I've gotten up to mid-90s efficiency with a stagnant mash. Crush matters more than anything. Stirring and fiddling around isn't necessary. A really good crush IS necessary, IF maximizing efficiency is a goal (and no, it doesn't have to be).

As a companion piece to Dave’s post, I have gotten low to mid 80s with No-Sparge, a coarser crush, direct fire and constant recirculation.

Many ways to skin this cat.

 

[Rev2010]

I'd say nothing, there is no efficiency difference. Like others have said, you can get very high efficiency with a non-stirred mash. I used to average 86%. When I recirculated using a Robobrew I averaged 81-83%.


Rev.

 

[Soulshine2]

I'm not an efficiency nazi(don't check, don't know, dont care,lol, my gravities come out right, my beer tastes good ) ...but Im definitely in the periodic stirring camp. I preheat my tun with water just at the mashing temp , then while its warming the tun , I let my water in the pot run up another 10 degrees before I dump it in to mash. By the time my grist hits the water ,I stir it in and the temperature dips from that addition, its just about spot on target +/- 2*F. I aim for the high side of that . I stir every 10 minutes. Mash no more than 60 minutes. then batch sparge until I hit my pre-boil volume.

 

[Rev2010]

but Im definitely in the periodic stirring camp.

I used to stir the mash up at 15 minute intervals. I'd read a number of people on here state that there's no benefit and that the heat loss incurred opening the tun and stirring each time is more of a negative impact that any potential gain if there actually were any. I stopped doing it, haven't seen any negative impact whatsoever.

Maybe give it a try your next batch? Just stir on mash-in then leave it alone till it's done and see if you observe any difference.


Rev.

 

[Soulshine2]

I used to stir the mash up at 15 minute intervals. I'd read a number of people on here state that there's no benefit and that the heat loss incurred opening the tun and stirring each time is more of a negative impact that any potential gain if there actually were any. I stopped doing it, haven't seen any negative impact whatsoever.

Maybe give it a try your next batch? Just stir on mash-in then leave it alone till it's done and see if you observe any difference.


Rev.

my tun is a 43 qt Igloo cube with a bazooka tube. I want to make sure the water/wort gets stirred around so I get all the available sugars out. If I had a round tun with a false bottom I probably would.

 

[Bassman2003]

The role of any type of mash agitation is to give more opportunities for the mash enzymes to make contact with starches. Much will happen with just adding the water but more will happen if you move the grain or water around the grain. How much? It would be a guess. Probably going from the 80% range to the high 80% range.

I went to a constantly slowly stirred mash and my beers are better attenuated than before. So I am a fan of some sort of agitation.

 

[Rev2010]

my tun is a 43 qt Igloo cube with a bazooka tube. I want to make sure the water/wort gets stirred around so I get all the available sugars out. If I had a round tun with a false bottom I probably would.

Shape and filter type doesn't matter when it comes to whether or not to stir through the mash length. And if extraction is a concern and stirring is your solution then definitely double batch sparge. You'll get to stir up the grains with each sparge addition. It's the sparging method I use. Again though, would it hurt to give only stirring on mash-in a try on one batch?


Rev.

 

[Big Monk]

I'd say nothing, there is no efficiency difference. Like others have said, you can get very high efficiency with a non-stirred mash. I used to average 86%. When I recirculated using a Robobrew I averaged 81-83%.


Rev.

Crush is a variable though.

IF you crush the grain fine THEN what you say is true. Also, you have to specify what efficiency we are talking about: Conversion, Lauter, Mash?

Mash agitation/stirring is about more than efficiency.

 

[brewbama]

I continuously recirculate but not for efficiency. I recirculate thru a RIMS tube for step mashing plus I really like how clear the wort is going in the kettle.

Incidentally, I get good efficiency.

 

[Dog House Brew]

I continuously recirculate but not for efficiency. I recirculate thru a RIMS tube for step mashing plus I really like how clear the wort is going in the kettle.

Incidentally, I get good efficiency.

Where I’m at too.

 

[Bobcatbrewing42]

I'm wondering what role stirring and circulating the mash plays in mash efficiency.

How much difference in efficiency will the following have, assuming a well insulated mash tun.

1) Stagnant mash, ie not circulated or stirred.

2) A stirred mash, where one periodically stirs the mash.

3) A circulated mash, where a pump is continually moving the liquid portion of the mash.

4) A continuously stirred mash, where a rake is continually mixing the mash.

5) A continuously stirred and circulated mash.

Can one get 80% efficiency with a stagnant mash ? Does circulating the mash liquid significantly decrease mash temperature gradients or otherwise somehow improve extraction ? How does stirring the mash compare with circulating the mash ?

Thanks

I'm using a fairly new (to me) HERMS system. After a dozen brews, I've come to stirring just once at mash-in to break up any lumps and recirculating for almost the whole mash rest. My efficiency and clarity is top notch and I'm happy with stepped mashes, IPA's, lagers, dark beers and everything that I brew.

 

[BandonBrewingCo]

No sparge BIAB, stir well at dough in, and after 20 mins when taking sample for pH check. Get high 80s mash effeciency

 

[Soulshine2]

Shape and filter type doesn't matter when it comes to whether or not to stir through the mash length. And if extraction is a concern and stirring is your solution then definitely double batch sparge. You'll get to stir up the grains with each sparge addition. It's the sparging method I use. Again though, would it hurt to give only stirring on mash-in a try on one batch?


Rev.

I already do. I don't just stop at 2 , I'll keep sparging until I get to the preboil volume as long as Im at the OG I need. OR I'll sparge until I think I got all the sugars out in the kettle. If I happen to be over my needed preboil volume a little,I'll boil it a little longer until I reduce it to the correct volume and OG. No problems.

 

[Shackleford_rusty]

Id agree crush and sparging method(to your system) probably matter more than stirring.
That being said i stir at dough in till it's smooth and no dough balls left, lid it and don't touch until there's 20 minutes left in the mash(60-90 minute mash don't matter) I've found if i don't stir in the last part of the mash im more prone to stuck sparges.
Although with my system efficiency is decided on sparging method
Fly 84-88%
Batch 74-78%
No Sparge +/- 68%
Not your original question, but these are my findings. Granted everyone's system will have different results im sure.

 

[mongoose33]

I'm now doing recirc through a RIMS tube, but when I was doing BIAB as well as traditional mash tun, I stirred at 15- and 30-minutes, and it bumped up my conversion efficiency about 8 percentage points.

A couple of stirs also has helped as I've learned about my recirc system. Still learning to dial that in, worked pretty well for last weekend's brew.