grain mill crush size/setting?

[Golddiggie]

I was just reading the May-June issue of BYO and I might make the barley wine using a hybrid system of BIAB in the cooler mash tun... Of course, I'm going to check the actual screen size in the tun, and determine if I need to use the bag as well. I'm using a bazooka screen in the tun, so I'm not sure how small a crush I could go with and not have issues. I'm also thinking of going with a 120 minute boil, so that I can use more sparge water... Using fermcap I should be able to get ~7.5 gallons of wort into my 8 gallon kettle. Or, I'll just use my 15 gallon kettle for that batch, and sparge a bit more.

The reason I'm thinking of using the bag in the mash tun is so that I can use a smaller crush size. I'll get as much water into it as I can (1.375qt/# or a bit more) and then sparge with as close to 3 gallons as I can.

Of course, I could just put that brew to the side for another time and go with a more modest ale with about 12-15# of grain in it... Then I could test the theory of a slightly smaller crush as well as more water in the mash. I will have to see if I can get away with a .035" crush with my current mash tun setup, and not get a stuck sparge... I also think I'll stir the mash more often than I have been. I used to stir about every 15-20 minutes. Since going with the cooler, I've only stirred at the start, to get the dough-balls out, and then towards the end. So perhaps more stirring is the real answer here.

I do think that it was a good idea to go with the smaller cooler now... The 70qt, while great for capacity, simply had too much dead-space in it. It was becoming more difficult to keep the temp where I wanted it during the entire mash time. Yesterday's batch was a lot easier to maintain, since there was less dead-space in the cooler.

Ok, so after all that, what would you change next?
Stir every 15-20 minutes during the mash (I typically do 90 minute mashes)?
Crush the grains smaller (what should I step to for the next batch? .037, .035, .033?)??
Mash with as much water as possible (keeping under 2qt/#) and sparge with as much as possible too? I would have to keep the volume to a level where I won't have boil-overs in my kettle, and try to keep the boil times to under 120 minutes (~90 would be ok)...

Thinking that I should be able to get to 1.5-2qt/# in the mash, and still sparge with a good amount of water. Thinking back, I was doing more 90+ minute boils when doing BIAB to get the volume to where I needed it. So maybe I should go back to that too. Water is cheap, as is time... I just need to be sure to have the correct amount of brewing water measured out before starting.

 

[Yooper]

Ok, so after all that, what would you change next?
Stir every 15-20 minutes during the mash (I typically do 90 minute mashes)?
Crush the grains smaller (what should I step to for the next batch? .037, .035, .033?)??
Mash with as much water as possible (keeping under 2qt/#) and sparge with as much as possible too? I would have to keep the volume to a level where I won't have boil-overs in my kettle, and try to keep the boil times to under 120 minutes (~90 would be ok)...

Thinking that I should be able to get to 1.5-2qt/# in the mash, and still sparge with a good amount of water. Thinking back, I was doing more 90+ minute boils when doing BIAB to get the volume to where I needed it. So maybe I should go back to that too. Water is cheap, as is time... I just need to be sure to have the correct amount of brewing water measured out before starting.

I don't stir beyond stirring like crazy at dough in. I check the temperatures in several places, and if it's different, it needs more stirring. I stir until the temperature is uniform throughout, which is MUCH more stirring that one can assume. Then, never again. I don't open the MLT at all, except I used to check the temperature after about 30 minutes when I first started because I didn't know if it would drop. After about 4 years with the same MLT, I drop less than one degree an hour so don't bother checking it anymore. (This is all without HERMS, which is a whole 'nother subject for me now!) I do 60 minute mashes except for adjunct-filled recipes.

My gap as been at .032" for years. It's perfect for me.

A good goal is to shoot for roughly "equal" runnings. What I mean by this is to mash with a good amount to get you to your pH and desired mash thickness, and then sparge with a roughly equal amount, using no more than 3 quarts per pound total. Does that make sense? It would vary with the size of the grainbill, but don't put more than a total of 3 quarts/pound of water though your grain.

 

[Golddiggie]

What kind of manifold/screen do you have in your mash tun? I'll see if .032" is larger than the spaces in the bazooka screen in mine. If it is, then I should be ok. If not, then I'll need to go between .039" and .032" for my gap...

For the amount of total water going through the grain, looking over my past several batches (all using the cooler MLT) I've been under 3qt/# total water... Highest was 2.844qt/#... I've adjusted my equipment in BeerSmith to account for the loss at the bottom of the cooler/MLT (2 quarts there) as well as what I leave behind in the kettle and in the hop bags. Pretty much nailed my volume into primary with yesterday's batch by making those adjustments.

I think I'll do the minimal stirring once the dough balls are gone, as well as the temperature is stable. I will try for a smaller crush size in the next batch too. Just need to see how small I can go with the bazooka screen... Anyone know on that point?

 

[Yooper]

What kind of manifold/screen do you have in your mash tun? I'll see if .032" is larger than the spaces in the bazooka screen in mine. If it is, then I should be ok. If not, then I'll need to go between .039" and .032" for my gap...

For the amount of total water going through the grain, looking over my past several batches (all using the cooler MLT) I've been under 3qt/# total water... Highest was 2.844qt/#... I've adjusted my equipment in BeerSmith to account for the loss at the bottom of the cooler/MLT (2 quarts there) as well as what I leave behind in the kettle and in the hop bags. Pretty much nailed my volume into primary with yesterday's batch by making those adjustments.

I think I'll do the minimal stirring once the dough balls are gone, as well as the temperature is stable. I will try for a smaller crush size in the next batch too. Just need to see how small I can go with the bazooka screen... Anyone know on that point?

If you've answered this already, I apologize, but you're batch sparging I assume? With the bazooka screen I assume you are, but I wanted to double check.

 

[cravej]

I'm also using the single infusion, no mash out model...

Why not try a double infusion? Raising the temperature during the second infusion can help make the sugars more soluble.

 

[Yooper]

Why not try a double infusion? Raising the temperature during the second infusion can help make the sugars more soluble.

Really? I've never heard that before. How would that happen?

 

[Golddiggie]

I'm mirroring, as close as possible, how I did BIAB all grain... Only difference is I now use the cooler to hold the grain and water at temperature, instead of fighting with pots.

I do the single infusions, no mash out method ("Simple single infusion mash for use with most modern well modified grains (about 95% of the time).")... I typically mash in the 150-154F range (depends on the brew) and then sparge with water that's 168-170F... Sparge rest times range from 15-30 minutes before I drain that wort into the kettle and start heating to a boil...

BTW, trying to heat up the wort in the mash, or measuring out the sparge water into equal parts, to then add a lower amount each time, is beyond my gear capability and my comfort zone. I already increase the temp with the second water addition (re: sparge)...

My brews are tasting really great, so I'm not looking to change the process all that much. Just looking to tweak where it makes sense to get a bit better efficiency on a reliable basis. If I could get over 75% for more average grain bills (under 16#) I'd be very happy... I'm even debating installing another ball valve into the 70qt cooler, with the original bazooka screen, so that I have two mash tuns available to me. That way, I won't need to do anything to use either one. Maybe I'll change the kettle valve over to a three piece SS model and shift the brass one over to the mash tun...

I've also noticed the need to vorlauf for both the mash and sparge wort. I've even gone so far as to use one of the nylon hop bags on the end of the silicon tube running into the kettle, to keep particles out of the wort that's going to be boiled. With the next batch, I'll probably secure that bag with a zip tie, so that I can hold it with just one hand and not worry about it slipping. I did it for the first time with Sunday's brewing. Like the results. Just another thing I didn't need to do when using the BIAB method. I hope to not go back to that camp, but if I can skirt both sides and get solid results, I can live with it. After all, what we do is in the pursuit of great home brew time and again. :rockin:

 

[weiht]

Too fine a crush can restrict the flow of sparge water washing the residual sugars. Need to ensure that the water gets good contact with the grains while washing it down

 

[cravej]

Really? I've never heard that before. How would that happen?

That is why you mashout, or at least raise the temperature of the sparge water. Raising the temperature of the grain bed to ~170°F makes it less viscous (more fluid).

See if John Palmer's explanation makes more sense:
http://www.howtobrew.com/section3/chapter17.html

 

[Golddiggie]

weiht, I already know that, which is why I'm looking for feedback from people who have the same screen I do to see what crush size they are using. If I can't get the info, then I'll start going lower a little at a time. The next step, for me, would be .037" gap.

cravej, as I already mentioned, I sparge once the mash is done with hotter water... I might try a bit warmer with the next batch to see what that does. I've not bothered to get a temperature reading of the sparge water/grain mix yet... So maybe I'll sparge with 175F water and see what it stabilizes the entire volume to. I'll be mashing at 152F in the next batch, a pretty common mash temp...

 

[Yooper]

That is why you mashout, or at least raise the temperature of the sparge water. Raising the temperature of the grain bed to ~170°F makes it less viscous (more fluid).

See if John Palmer's explanation makes more sense:
http://www.howtobrew.com/section3/chapter17.html

That's not what you said at all. You said to raise for a second infusion, which I didn't understand to be a mashout. If you're talking about a mashout, I'd agree although for a batch sparge it doesn't really help.

 

[cravej]

That's not what you said at all. You said to raise for a second infusion, which I didn't understand to be a mashout. If you're talking about a mashout, I'd agree although for a batch sparge it doesn't really help.

The point I was trying to make is that you need to raise the temperature. When or how isn't as critical. A second infusion isn't much different from a mash out.

The 'efficiency' problem that Golddiggie is experiencing may be due to the process and not how fine the crush is.