A good night sleep helped.
All given info considered, I would finger channeling.
When you calm down consider doing a batch-sparge brew with everything else the same...
Cheers!
I've always done batch sparges. This was only the third brew I tried fly sparging on. My efficiency has
SUCKED for the past 6 or 7 brews and 100% of my focus and attention has been on that. Everything I read said fly sparging was more efficient than batch sparging. Maybe it is -
maybe it isn't... I'm going back to batch sparging.
I would expect using a grain bag as a simple liner in a bottom drain MLT is going to result in a highly preferential flow path straight down the middle of the grain bed.
Elevating the bag with an FB would solve that...
Cheers!
I use a couple of my wife's cooling racks (
crisscrossed). They're only 10" so there's minimal space below. I didn't want to run into the problem of having 5" or 6" inches of liquid sitting beneath a dry grain bed and have to adjust how much mash water I use. This recipe was 14.5 pounds of grain and I used 17 qts of water.
... Grain compaction. Do you ever move the mash around? Stir it? Is it hanging so heavy/packed/tight that the fluid cant get through the grain? It may fully wet during strike but possibly inadequate subsequent flow through after it gets a little goopy and settles in. Like some of the prior peoples posts, my gut says you are channeling or the wort is just flowing mostly around the whole ball/bag.
I tried stirring it every 20 minutes on a 60 minute mash two brews ago. I didn't notice any difference and it just seemed like extra work and a pain in the butt. Plus I have no way to directly heat my mash. Once it's closed up I only lose about 1 degree in 60 minutes. Opening it and stirring it every 20 minutes dropped it down 4 or 5 degrees - wasn't worth it to me.
Grain freshness and/or quality.
The brew shop I go to is pretty busy. I overheard the owner talking about how breweries get first pick on grains and brew shops get whatever is left. I thought I heard him say he does about $15,000 a month just in grain. Maybe some of the less popular grains might sit around, but everything I used for this brew was pretty standard.
... Maybe do a simple lighter pale brew and see how your system and processes turn out without a large grain bill.
I did - that's why it's so frustrating. I brewed that Belgian quad that was supposed to be 11% and it turned out being like 5.5%, (
and sour). 21 pounds of grain and 2 pounds of Belgian candi syrup for a 5.5% abv beer that's almost undrinkable. If I wasn't so cheap it would be undrinkable. After that I did brew several smaller lighter beers to see if I could get a handle on things. My efficiency was still low, but not drastically low, so I assumed I was making progress. I brewed a stout that is awesome. It was supposed to be 7% but came in at just under 6%, so I was miffed but not majorly upset. It tastes great. So this time I decided to cross my fingers and go big again. This was supposed to be a 10.6% Imperial stout. Coming in .031 points low was like a kick in the gut.
... Is the mash pH ok? 5.2 to 5.6 ish?
5.5, I checked it after I stirred in the grain, so maybe 3 to 4 minutes in.
... Have you stabbed the mash deep with a thermometer and verified your mash temp is truly what the grain is feeling?
I have 3 digital thermometers and the probes are all only about 4 inches. I do have a 12" inch dial thermometer I used to use way back when I was doing extract kits on the stove. It takes forever to get to temp and I never checked the accuracy, so I don't use it.
... Check your conversion, do the Tincture of Iodine test ($3 at your local pharmacy for a bottle of the stuff).
Yup
... My hunch is it is something incredibly simple and you'll figure it out and be happily tipping your next brew.
That's my hunch too... which is why it's so frustrating. With each brew I think, okay I got this now . . . and then . . .
You have a keggle, you have a bag. Mill that grain really fine. Don't sparge at all. Your efficiency is primarily controlled by the milling of the grain. Sparging can get you more sugars but only from the available sugar source. If your grains are milled too coarse, the starches in the middle of the grain particles don't gelatinize and thus cannot be converted and are lost.
I milled it as fine as I could get my cereal killer, (
I believe it's about .025?). I even ran thru twice this time. Personally, I think it's a combination of the bag and the fly sparge that's screwing me up. I don't want to abandon the bag just yet because the theory of crushing super fine makes a lot of sense to me. But I'm definitely going to give up fly sparging. This last fly sparge was my last fly sparge. It seems like if all the conditions are absolutely perfect then fly sparging is the way to go. But if even one minute simple detail isn't in line, fly sparging is the worst way to go.
So I am not a BIAB guy, but for all of my beers, I dont use the standard 1.25qt per 1lb water/grain ratio as it always seems the mash gets a bit too "thick" for my liking and my recirc is just not as efficient as I like it to be and with a few of my beers, stuck (or very slow) sparges (which introduces air pockets which is not desired) were also experienced as I crush just a bit more on the fine side but I dont double crush.
I'm going to try thinner mashes as well. It's been awhile since I read about mash ratios and the theories behind thin versus thicker. Whatever I read convinced me to stay around 1.25 - I think mostly just so I was using a consistent given so I wouldn't have to wonder if my mash being too thin or too thick was a factor. But yeah, I think I am going to shoot for around 1.4 to 1.5 from now on.
I'm confused on one thing--why would you be using a BIAB bag but also fly sparging? Doesn't that kind of defeat the purpose of BIAB's simplicity?
To say nothing of the extra time involved?
In retrospect . . . yes. I was having issues with efficiency and trying all kinds of things to raise it. Fly sparging was one thing I tried. And now that I've tried it, I'm done with it. I contemplated going with a FB, doing away with the bag and doing fly sparges. Instead I've decided to keep the bag for awhile and abandon fly sparging.
... Can't really tell from the pics--it looks like your mash tun is on a burner. Is that to help maintain temps? Or just a stand?
That's just a 2x4 frame I built. It's a bottom drain so no way to really heat it with a flame underneath. I considered buying a pump and making a recirc system - but at this point I've decided I want to go backwards and make things simpler rather than adding more contraptions that just complicate things and add more stuff to go wrong. My beers were "okay" back when I started with minimal equipment. I started adding this and that to make them even better, and looking back it seems like things have just gotten more complicated and the beer isn't as good. My first few batches were partial boil, BIAB extract kits in an 8 gallon pot on the kitchen stove . . . I'm seriously thinking about just going back to that. I started at 10:30 yesterday morning and finished up at 4:30 in the afternoon. I kind of miss the 2 hour brew days in the comfort of my kitchen.
... But then again, why not just BIAB? FWIW, when I switched from mash tun to BIAB, I dropped the gap on my mill from .035 to about .020. Efficiency is great, and no channeling since I raise the bag and squeeze it.
Just some thoughts. Good luck and I'm anxious to find out what solves this problem for you.
Thanks - that's the direction I'm leaning in.
I was just wondering a few things
does this happen for low gravity beers?
what's your strike temp?
do you stir the mash?
have you been testing with iodine?
Mash temp for this was 153*F. grain temp was 80*F and strike water was 164*F. Hit 153*F dead on.
Yes I stir it when I dough-in - that's it.
Yes, I do the iodine test. Have tried it with and without chalk. Not sure I noticed a difference and with a 4 year old daughter in the house finding chalk is sometimes more trouble than it's worth.
Thanks for all the feedback. I was pretty discouraged last night and posted this more as a vent just to get my frustration out. I didn't expect so many encouraging responses. Very much appreciated. Thanks and CHEERS!
