redrocker652002
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Not sure if this goes here but wondering something. Is this crush too fine?
Grain crush
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This depends somewhat on your equipment, but the crush looks like it's within a normal range.
You really can't go too fine with BIAB crush. That's the beauty of it. No stuck sparge!
redrocker652002
Well-Known Member
I have to say that having my own mill has been a game changer. I went from somewhere around 65% efficiency to probably 70 to 75%. And it is another part of the process I can be involved in. Although, the last brew day I used the hand crank. For almost 11 pounds of grain that was quite an effort. LOL.
I don’t know what kind of mill you have, but on my Cereal Killer, I set the gap to the narrowest setting on the first day and have never changed it since.
bobtheUKbrewer2
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Wepeeler I beg to differ - recently a 25kg bag of crushed maris otter was way too fine. It was reluctant to pass through the bag and crude recirculation (4 litres out of bottom tap) poured in the top would have caused overflow so I had to add each 4 litres over about 10 minutes. Final beer was unaffected I am glad to say.
waynetempro
Active Member
My rule of thumb is to set the roller gap to snuggly fit 2 regular sized business cards.
I use a Corona mill, and get about the same results as your picture. I hit my numbers pretty close. I only had one stuck sparge a couple years ago. I added another gallon of hot water, stirred it, and proceeded as usual. I mostly hand crank, but have used a drill. I’d say; Rock on!
The fineness of the crush will determine how long it will take for full conversion and somewhat control the efficiency of the mash. With a very fine milling the conversion happens way quicker than most of you would believe. As the milling becomes more coarse, it takes longer for the starches to gelatinize and extracting the sugars from the grain particles becomes less efficient.
If you recirculate with BIAB you must use a coarser milling or your bag will gets its pores clogged and the wort won't flow through. Then since you have to use coarser milling your mash period becomes longer and your mash temperature falls. If it falls far enough, you will want to add heat and this becomes another problem areas as it is really easy to heat part of the mash to the point that you destroy the enzymes that are needed for conversion.
I mill my grains to near flour consistency and add them to water that is at the proper strike temperature. Then knowing how fast conversion really, I don't try to recirculate or add heat because neither is necessary. With no sparge, the efficiency I get is approximately 80%. With sparging I can bring that to near 95% which I think is beyond necessary.
If you recirculate with BIAB you must use a coarser milling or your bag will gets its pores clogged and the wort won't flow through. Then since you have to use coarser milling your mash period becomes longer and your mash temperature falls. If it falls far enough, you will want to add heat and this becomes another problem areas as it is really easy to heat part of the mash to the point that you destroy the enzymes that are needed for conversion.
I mill my grains to near flour consistency and add them to water that is at the proper strike temperature. Then knowing how fast conversion really, I don't try to recirculate or add heat because neither is necessary. With no sparge, the efficiency I get is approximately 80%. With sparging I can bring that to near 95% which I think is beyond necessary.
redrocker652002
Well-Known Member
I am sure I can search it, but I am being lazy. Is there some sort of test or way to determine when full conversion, or at least a percentage of it, has been completed? Or is it just looking at our OG and seeing where your brew software puts it at a certain percentage? Thanks in advance.
There are two ways to determine full or nearly full conversion. One is to test for the presence of residual starches using iodine. Take a small amount from the mash that includes lots of grain. Drop a drop of iodine on it. If there is starch there iodine will turn blue.
The second method is to calculate the possible sugars and then using a refractometer or hydrometer, determine the percentage of the possible sugars have been extracted.
It is possible to crush too fine, even with BIAB. I set the roller gap way low once, made a powdery-like crush, and lautering was a mess. Hoisted out the bag and it was like a giant balloon full of water. Glad I had it hanging from a ratchet pulley! Had to squeeze a lot.
Go to the auto parts store and pick up a feeler gauge. That way you can actually measure the roller gaps. Many BIABers set the gap for around .025", give or take a bit. Experiment and see what works best for you.
Go to the auto parts store and pick up a feeler gauge. That way you can actually measure the roller gaps. Many BIABers set the gap for around .025", give or take a bit. Experiment and see what works best for you.
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And @redrocker652002 , if you really wanna go deep down a rabbit hole, check out this site.
I use it to see where max expected R% refractometer reading after mash would be, vs what I got, to see where I landed. I also BIAB, and corona grind VERY fine. Only two times had a problem: once doing mostly oats, and once doing @Miraculix "Hazy Cheapskate" with a 5# bag of flour, therefore not unexpected.
+1. I use a feeler gauge set at .022" which is where I set the gap the first time I ever used the mill. I've never changed it, but I do make it part of my routine to check it every time prior to milling. I typically get between 75%-80% mash efficiency without sparging. The only times I've ever had an annoyingly slow drain is when I brew my American Wheat, which is ~60% white wheat.
redrocker652002
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Being a gear head, I think I have about 3 or 4 of those laying around. Will have to dig one up. Haven't used them in years as plugs come pregapped now. LOL
For biab I go as fine as my Corona type mill let's me grind it. As others already said, there's not such a thing as a too fine crush when biab. It just increases the efficiency the finer you go!
Once again it's clear that different people's M definitely MV. As usually happens in threads on this topic, you've already gotten "no such thing as too fine a crush for BIAB" and "crushed too fine and plugged up my bag" responses. I don't have a mill, but I have taken grain crushed at my LHBS and put it through my food processor to turn it into almost flour for BIAB with a dunk sparge and gotten good results. You probably just need to experiment and figure out what works best for you.
It depends on the bag. If the pores of the bag are too fine, it can clog. Especially with protein richer grains like wheat and such.
I use Wilser bags, which are fine mesh, so I don't go too tight with the crush. And for anything with more than 10 or so percent of wheat or rye I add some rice hulls. Otherwise I get the dreaded bag-o-wort when I hoist it out.
With a .025" mill gap I usually get around 80% efficiency. When crushing wheat or rye I have to tighten up the rollers a few thousandths due to the smaller kernels--maybe down to .020 or so.
AZ Maverick
Well-Known Member
I do BIAB with a Wilser bag.
I crush grain using a 2 roller Hullwrecker set to .028" (I could probably go a couple thou tighter) and I get very good results.
I crush grain using a 2 roller Hullwrecker set to .028" (I could probably go a couple thou tighter) and I get very good results.
I’m a BIAG guy. I use a 400 micron bag and do a recirculation. It’s works fine for me. 200 micron bags are ok if you use a coarser grind.
This is what I'd consider a good crush for a perforated false bottom or an AIO malt pipe. This is my "normal crush" though probably a touch larger than mine. I think this is a gap of like .035" where my normal is .030 to .032"
This is what I crush to for BIAB. It looks like a .022-.024 gap on my mill with 2" rollers.
This is what I crush to for BIAB. It looks like a .022-.024 gap on my mill with 2" rollers.
