Forgot to Stir Batch Sparge

[3 Dawg Night]

I've been pretty consistent with ~73% brewhouse efficiency. I use a converted 10 gal Igloo cooler MLT, and I batch sparge. On Saturday, I brewed an American Wheat, and I had a great brew day. Then, I went to measure my OG, and I was six points low (1.046 vs 1.052), giving me a brewhouse efficiency of 68%. I'm not one to maximize efficiency, but I would like consistency. I've been racking my brain trying to figure out where I screwed up, and then it hit me this evening: I forgot to stir after adding my sparge water! I drained off my first runnings, infused my sparge, and then drained my second runnings. I had no idea that stir was so important, but it makes sense, since the whole point of the sparge is to rinse the residual sugars off the grains.

Let this be a lesson, boys and girls: make a checklist, and follow it!

 

[bracconiere]

I'm not one to maximize efficiency,

i don't batch sparge, but if i did. i'd make sure to stir the second runnings, and let it sit for a while also....

edit: and now i have a couple rafracs, i'd probably draw off a little to check gravity and see when it stops going up to know when to drain....

 

[IslandLizard]

I brewed an American Wheat

How sure are you the wheat malt was crushed/milled adequately?
Wheat kernels are much smaller than barley, and really need to be crushed (preferably separately) with a tighter mill gap. Otherwise they'll drop mostly uncrushed through, killing your mash efficiency and wheat character.

 

[3 Dawg Night]

How sure are you the wheat malt was crushed/milled adequately?
Wheat kernels are much smaller than barley, and really need to be crushed (preferably separately) with a tighter mill gap. Otherwise they'll drop mostly uncrushed through, killing your mash efficiency and wheat character.

Good question. I crushed the 2-row at 0.033" and the wheat at 0.025".

 

[IslandLizard]

Good question. I crushed the 2-row at 0.033" and the wheat at 0.025".

OK, that's perfect!
I use about the same mill gap settings, getting excellent mash efficiency (82-85%) with a converted cooler mash tun and 2 batch sparges of equal volume. I mash at 1.5 qt/lb.

 

[Erik the Anglophile]

I don’t stir that hard, but still a little stirring. On the other hand i sparge in a bucket-in-bucket setup and drain of the first runnings before dumping the sparge water on the grain bed and suppose that stirs it up quite a bit.
Also heat the sparge water enough so the grains+ water reach a temp of 75-80 c and let sit for 5 minutes, then you get a combined sparge and mashout.

 

[Bramling Cross]

How sure are you the wheat malt was crushed/milled adequately?
Wheat kernels are much smaller than barley, and really need to be crushed (preferably separately) with a tighter mill gap. Otherwise they'll drop mostly uncrushed through, killing your mash efficiency and wheat character.

Although prior posts suggest that this isn't the issue, this usually is the issue. I'll also add that keeping your mash temp up during run off is a big deal when dealing with gooey stuff in the mash tun. With batch sparging, that second sparge is guaranteed to hit 168-170F, but that first sparge often can fall a bit short. In those cases, run off a pasta pot worth of wort, boil it on your stove then use that as a cheater's decoction to get that first sparge into the correct window.

Frankly, that'll only help around the margins, though. I honestly think it's your crush. I know better than to under-crush my wheat and I still keep doing it.

 

[3 Dawg Night]

Frankly, that'll only help around the margins, though. I honestly think it's your crush. I know better than to under-crush my wheat and I still keep doing it.

I'm pretty sure it's not my crush. I checked it with a feeler gauge before and after, and my crushed kernels looked great. I'm still convinced it was not stirring. I think my sparge probably just channeled around what was basically a humongous doughball!

 

[IslandLizard]

Re: The Crush:

Although prior posts suggest that this isn't the issue, this usually is the issue.

I totally agree, for most homebrewers that's the usual issue, especially when getting a typical LHBS, or worse, NB or MB "crush."
At his gaps widths (very close to what I use) I don't think that's the OP's issue here.

But the gooeyness certainly plays a big role, as you said:

I'll also add that keeping your mash temp up during run off is a big deal when dealing with gooey stuff in the mash tun.

Higher temps makes a gummy (beta-glucan rich) mash/sparge more fluid as does good stirring since it's a non-Newtonian fluid (got that from John Palmer). If still too sticky, stir more.
By adding rice hulls, as a wise brewer should when using a higher % of (husk-less) wheat and flaked products, it provides for better permeability (thus lauterability) of the grain bed.

In those cases, run off a pasta pot worth of wort, boil it on your stove then use that as a cheater's decoction to get that first sparge into the correct window.

Sorry, but that's basically doing a mashout, not a decoction at all. And yes, raising the (mash) temps at the end helps with lautering.
For a decoction you'd need to boil the thick part of some of the mash.

I honestly think it's your crush. I know better than to under-crush my wheat and I still keep doing it.

Tsk, tsk...
Do you mean you sometimes forget to weigh out your wheat, rye, oat malt, etc. separately from barley, so you can't mill them on their own ideal gap?
What gap(s) do or would you use?

 

[Bramling Cross]

Tsk, tsk...

It's partly a lack of intestinal fortitude on my part and part rational trade off. I started off with a Corona Mill and that made wheat beers fun. I used to joke that I'd plan an awesome wheat beer, brew a damned wheat beer, then pitch yeast into the last #$($*$@ wheat beer I'll ever make.

My equipment and knowledge has improved markedly since then, but I still tend to treat wheat with a bit more care than is necessary. As for the rational trade off, I'm comfortable with trading a small bit of efficiency for a smooth, enjoyable brewing session.

I have a wheat beer scheduled for this coming weekend. I think I might take my brave pills and give .025 a shot.

Last, when I read the OP's post after work last night I saw 68% efficiency and jumped to the conclusion that he was down at least 10 points. That was a dumb assumption on my part. Stirring easily explains 5 points.

PS: As for "Cheater's Decoction," I picked that term up recently and it made me chuckle. I agree, it sure isn't a decoction but it is a handy term for something that doesn't seem to have a term. Perhaps we can borrow from Chris Colby's reiterated mash technique and call it a "reiterated infusion?"

 

[mbg]

Ha - I had just the opposite experience yesterday. I did a 4-step temperature mash on a German Alt. My pre-boil gravity was higher than expected giving me a 91% mash efficiency. Was so excited that maybe the step mash did this until my OG was only two points above the pre-boil and one point above the estimated OG. Must have missed mixing the mash - I have an Anvil Foundry and use a false bottom and bag.

 

[doug293cz]

I'm pretty sure it's not my crush. I checked it with a feeler gauge before and after, and my crushed kernels looked great. I'm still convinced it was not stirring. I think my sparge probably just channeled around what was basically a humongous doughball!

I agree that lack of stirring the sparge is responsible for all/most of your efficiency loss.

At the completion of initial run-off of the mash, the grits are all coated with a layer of high gravity wort. To maximize the amount of sugar that you recover from that adsorbed wort, you want the sparge water to come into contact with all the grits, so that the sugar concentration is homogenized everywhere. This insures that the wort left clinging to the grits after sparge run-off is as low an SG as possible, and thus contains the least amount of sugar possible.

Brew on

 

[seatazzz]

I'm going to add on here and ask, do you stir during the initial mash as well? I started doing this about every 20 minutes or so, and saw an increase in my SG. I stir after adding the sparge as well, and recirculate it for about 10 minutes before running it into the BK. My mash tun is not the best, and Sunday's brew the temperature dropped from 152 to 143 in the 60 minutes (yes that's bad). I compensated by sparging at 170, stirring the heck out of it, and managed to get 1.040 preboil from first runnings of 1.057; finished out at 1.061 after the boil was done. I don't calculate my efficiency (math, ugh) but this works for me.

 

[3 Dawg Night]

@seatazzz I give everything a good stir at dough in, and then I don't touch it again until sparge. I used to stir every 10 minutes, but I feel like I'm better off retaining my mash temp.

 

[hottpeper13]

I don't touch hot liquid in my brewery, just turn on the pump........underlet my friend, underlet, it stirs it self.

 

[hout17]

I stir the initial mash in and make sure the grain is stirred in very well then close it up and let it sit the 60 minutes or whatever specified time. I don't stir because I want to hold my target temp as long as possible. When I add sparge water I stir it in real good and then let it sit ten minutes. So far I've gotten good results and have either hit my target or been a few points over. This is with a cheapo 48 quart $20 Coleman cooler fitted with a spigot and bazooka screen. It's becoming apparent to me that my efficiency is tied to my crush and stirring the grain in very well initially and stirring in the sparge water also.

 

[3 Dawg Night]

I stir the initial mash in and make sure the grain is stirred in very well then close it up and let it sit the 60 minutes or whatever specified time. I don't stir because I want to hold my target temp as long as possible. When I add sparge water I stir it in real good and then let it sit ten minutes. So far I've gotten good results and have either hit my target or been a few points over. This is with a cheapo 48 quart $20 Coleman cooler fitted with a spigot and bazooka screen. It's becoming apparent to me that my efficiency is tied to my crush and stirring the grain in very well initially and stirring in the sparge water also.

This is basically my process.

 

[doug293cz]

I stir the initial mash in and make sure the grain is stirred in very well then close it up and let it sit the 60 minutes or whatever specified time. I don't stir because I want to hold my target temp as long as possible. When I add sparge water I stir it in real good and then let it sit ten minutes. So far I've gotten good results and have either hit my target or been a few points over. This is with a cheapo 48 quart $20 Coleman cooler fitted with a spigot and bazooka screen. It's becoming apparent to me that my efficiency is tied to my crush and stirring the grain in very well initially and stirring in the sparge water also.

You might want to consider a good aggressive stir before you initial run-off. Temp stability at that point means nothing. If you have no false bottom or standing wort above the grain bed, then it might not make much difference, but if you have wort outside of the grain mass, it is a good idea to help maximize lauter efficiency.

Brew on

 

[hout17]

You might want to consider a good aggressive stir before you initial run-off. Temp stability at that point means nothing. If you have no false bottom or standing wort above the grain bed, then it might not make much difference, but if you have wort outside of the grain mass, it is a good idea to help maximize lauter efficiency.

Brew on

That's a great point and something I hadn't thought about for some reason. I'll have to give it a shot on the next go around.

 

[3 Dawg Night]

That's a great point and something I hadn't thought about for some reason. I'll have to give it a shot on the next go around.

If you stir, you have to remember to give it 10 minutes or so for the grain bed to settle, just like with your sparge. I do that about half the time (i.e., when I remember), but I haven't noticed a huge difference in efficiency.

 

[doug293cz]

If you stir, you have to remember to give it 10 minutes or so for the grain bed to settle, just like with your sparge. I do that about half the time (i.e., when I remember), but I haven't noticed a huge difference in efficiency.

You only need the grain bed to settle if you are doing a fly sparge. With batch sparge, or no-sparge, it makes no difference.

Brew on