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Crush too fine?

Mashing
#1

So I finally got to use my new Cereal Killer mill on my Vienna lager yesterday. I’m wondering if my crush was a little too fine. I adjusted the gap to the suggested .037" using a feeler gauge. First thing that was weird was that 10lbs of grain absorbed over 2 gallons of water. I started with 4.5g of strike water and ended up with 2.3g in the kettle.

I sparged with 5 gallons and only got about 4.5 gallons out but realized the “mush” was blocking the bazooka screen so I scraped some of that away from the screen and the remaining half gallon (and a whole bunch of grain/meal drained out. Is this normal to have the last 0.5g or so blocked?

Total efficiency was around 77% at the end of the boil. I ended up with a bit of ground meal/flour type material in the kettle. I realize this is probably unavoidable to a certain degree since the bazooka screen can only stop the husks from getting through. I did vorlauf about 3 times and I was still getting a little bit in my runoff.

#2

The rule of thumb is crush until you get a stuck mash… Doesn’t sound like that happened. I care less how much water I use as long as I hit target volumes and your water loss doesn’t seem outrageous to me. I use a bazooka tube too but I get pretty clear runoffs. I vorlauf 3-4 times a half a gallon per. That said, I do kinda baby the mash bed and use the back of the brewing spoon when adding runoff gently on top of mash. My rollers are at .030". Might be hard to get a bed to setup well in a large cooler. What size cooler?

Did you end up getting hot and heavy with the lactic acid?

#3

Using a 70qt cooler so the spent grain when I’m drained is usually about 1/4" above the top of the screen. Lots of extra space in there.

Ended up diluting with distilled 50/50 and used about 1.5mL in my strike and 1.3mL in my sparge water.

#4

I think that cooler is too big for average gravity 5g batches. Time to step up to 10G! :cheers:

I like your water strategy. Hope it turns out well.

#5

I had the same kind of experience with my mash kettle a few months ago, and it was the first time I had used NB’s pre-crushed grain in quite some time. I actually posted about it here, and got quite a few responses from people saying that it’s way better to go a little overboard with the crushing than to go too coarse and get crappy efficiency. Personally, I don’t own a grain mill, so I can’t comment on how you should have the rollers set. But I’d rather go a little coarser and get slightly lower efficiency than use grain that’s ground too finely, even if I get a really high mash efficiency that way. I’d rather just compensate for the lower efficiency by using a little more grain and not have a brew day that takes forever. Incidentally, I would have to say that the water absorption you’re specifying does seem rather high, and it only makes sense that this would be the case when you’re using over-crushed grain. More exposed endosperm would mean more material to serve as a trap for the mash liquid, I would think.

#6

I use the default gap in my BC and get between 80-85%. I really don’t care to crush finer to get higher efficiency. Cost savings are negligible for 5 gallon batches and I heard somewhere (Jamil maybe?) that higher efficiencies can mean a lower quality wort. Also, I measure my mash efficiency with my pre-boil gravity, not post-boil.

#7

A 70qt rectangular cooler is a little on the big side for a 5 gallon batch. Lots of dead space in there. If you want to use it your best bet I think will be to have it at an angle.

#8

I tip it at the end to get every little bit of water out of it. I went with the bigger one cause it was the most versatile.

#9

You need several inches of grain bed above the bazooka tube for it to function properly. Deeper the grain bed, the better the lauter. Tilting is great idea. I wonder if a hose braid would work better in that cooler? Also, there is likely a lot of heat loss with that much free space.

I regularly make 10G batches of typical strength and have no issues fitting them in my 44qt.

#10

I put my strike water in first about 12 degrees hotter than my mash temp and close the cooler for about 10 minutes to get everything preheated. Then I add my grain and stir till im at my mash temp and close it. Last Sunday it was about 25 degrees out and I lost about 1.5*F over about a 70min period so it holds heat pretty good.

I may have to look into that. The hose braid always seemed like it would be more susceptible to stuck sparges.

#11

for what its worth, I’ve done 30 batches with a hose braid and all preforms well for me. mine is about 3/4 (about 15")the length of the cooler if that makes a difference. I also weight it down with large washer on the end so that it dose not come off the bottom of the cooler while mixing.

#12

I may have to look into that. The hose braid always seemed like it would be more susceptible to stuck sparges.[/quote]

Curious as to why you would think that? I’ve never owned a bazooka screen but seems like it would function in much the same way as a hose braid.

#13

I may have to look into that. The hose braid always seemed like it would be more susceptible to stuck sparges.[/quote]

Curious as to why you would think that? I’ve never owned a bazooka screen but seems like it would function in much the same way as a hose braid.[/quote]

Because the bazooka screen doesn’t compress with weight. It’s rigid and maintains it’s shape. A hose braid can be crushed by too much weight and I could see that being a cause of stuck sparges.

#14

The braid really doesn’t need to be that long, a few inches should be fine. The one I use is probably 4-5 inches. Also no need to weigh a shorter braid down as it won’t get in the way of your stirring.

#15

[quote=“mattnaik”]
Because the bazooka screen doesn’t compress with weight. It’s rigid and maintains it’s shape. A hose braid can be crushed by too much weight and I could see that being a cause of stuck sparges.[/quote]

Gotcha, IME that isn’t an issue with a SS braid…now a plastic braid painted to look like SS is a different story altogether

#16

I may have to look into that. The hose braid always seemed like it would be more susceptible to stuck sparges.[/quote]

Curious as to why you would think that? I’ve never owned a bazooka screen but seems like it would function in much the same way as a hose braid.[/quote]

I think the braid has a much finer mesh than the bazooka and would keep out some of the finer particles that are not being filtered naturally from grain bed.

Happy that the temp remains stable in that big guy. My ice cube is decent after I insulated the lid.

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