Grain crush question

[rjstew]

I've always experienced very poor efficiency in every single all grain batch I've brewed (~25). Typically around 65% with a 1.065 OG and a terrible 53% with a recent 1.092 OG. I expected low efficiency with the 1.092, but closer to 60%, not 53%. I typically mash low, around 151 for 90 minutes, stir furiously for the first 5-10 minutes to make sure there are no dough balls or uneven temps and batch sparge.

Someone mentioned on here that it may be my grain crush since I'm consistently so low. I've always crushed my grains at my LHBS myself. They have a mill in the back where you dump your grains and go at it. I just crushed 30lbs today for a Belgian Dark Strong Ale I'm brewing this weekend and figured I'd take some pictures of the grain crush. Someone mentioned milling twice, but this pretty much looks pulverized to me. Not sure you'd want it any more crushed because it would just tear the husks apart.

Thoughts?

 

[GilSwillBasementBrews]

That doesn't look bad to me. The higher the gravity beer you're aiming for the worse your efficiency gets though. Also I stir my mash every 10-15 minutes and picked up some efficiency percentage that way.
Maybe try stirring more and maybe brew a lighter gravity beer and see if your efficiency is still low. I mill my own at home but my grind looks pretty similar to yours and I average around 83% mash efficiency. I batch Sparge and stir like it owes me money. Just my .02


Sent from somewhere to someone

 

[peterj]

Yeah I'm seeing a bunch of intact grain, especially in that middle picture. Looks like a crush issue. I would look into getting a grain mill or running it through twice. Or you could ask if you can tighten the gap when you mill your grains.

 

[rjstew]

Yeah I'm seeing a bunch of intact grain, especially in that middle picture. Looks like a crush issue. I would look into getting a grain mill or running it through twice. Or you could ask if you can tighten the gap when you mill your grains.

If you zoom in you can see they're actually cracked hulls with the insides removed, not intact.

 

[turkeygecko]

This looks like a loose mill gap to me, too. I would double crush, or invest in a cheap but good mill (I love my $99 shipped Cereal Killer from AIH), and know what your mill gap is.

Also, people throw the term efficiency around a lot... but there are a lot of different ways to define. If you're talking about brewhouse efficiency, you can have large swings from factors like how much you leave in the kettle. An IIPA with a ton of hop matter left in the kettle is going to be a lot different than a Pilsner with very little.

 

[stpug]

My opinion - like you need another one - is that the crush looks very good, spot on! It looks close to mine (I get a little more flour but you're probably crushing with a 3 roller or large diameter mill). I would not think that your efficiency issues are caused by the crush of this grain. I suspect your culprit lies elsewhere - and there's plenty of places for it to hide

Your mash efficiency (preboil) is probably the best measure of crush so keep good notes of that.

 

[30Bones]

Looks great to me as well when you zoom in.

 

[mlafnitzegger]

my opinion - like you need another one - is that the crush looks very good, spot on! It looks close to mine (i get a little more flour but you're probably crushing with a 3 roller or large diameter mill). I would not think that your efficiency issues are caused by the crush of this grain. I suspect your culprit lies elsewhere - and there's plenty of places for it to hide :d

your mash efficiency (preboil) is probably the best measure of crush so keep good notes of that.

+1

 

[Ozarks Mountain Brewery]

I generally get 10% flour with mine but Ive been using a bag lately so finer helps

 

[Jupapabear]

Do you batch or fly sparge?

 

[blizz81]

It looks pretty crushed to me. Can always take a feeler gauge in to measure, they're cheap.


We were on a string of 60s% brewhouse efficiency where I had the crush pretty tight already - .030. Tightened to .028 and tried a couple other things at the same time (got a big stainless mash paddle as opposed to the long plastic spoon / long plastic paddle with a tiny head we had, longer mash - think we started 90 vs 60, batch sparge with valve not at full bore, and used local water + campden vs. filtered Brita). Have been in the 80s with four or five batches all above 1.070 since. In our case, probably the mash paddle made the biggest difference, but hard to know.

 

[rjstew]

I batch sparge.

I'm surprised a mash paddle would help that much. I use a big stainless spoon, about 3" in diameter. I don't see how that could be a problem.

As far as efficiency, I'm taking the reading pre-boil. It's still always below 70%.

 

[blizz81]

I'm surprised a mash paddle would help that much. I use a big stainless spoon, about 3" in diameter. I don't see how that could be a problem.

To me, just thinking about a spoon or something solid and / or not huge going through my mash, I could envision how much effort it would take to really mix all that up and be sure you don't have any grain balls. I could be making it up in my head but with a porous and large-headed sturdy paddle it's evident things get awfully more turbulent / mixed up than my efforts with spoons and the small-headed paddle I'd used before. (Of course this depends somewhat on the size of the grist, thickness of the mash, and vertical vs. horizontal mash tun)

Even now I still dough-in pretty slowly as I'll see grain clumping if we accidentally start dumping too much in. Of course, at .028, we're fairly flour-ey too, but conditioning grain too, so there's still a lot of intact husk material.

 

[stpug]

Is there a chance that you're leaving behind a large amount of sugar-rich wort on your initial (and successive) runnings? My friend had this problem when using a 70-quart square cooler as his MLT. The long of the short is, the siphon would break during the runnings leaving behind a significant portion of sugar-rich wort in the MLT. On the first batch sparge, he would regain some of that but the siphon would break again and he'd never regain those precious sugar-rich runnings due to already achieving preboil volume and inability to start siphon.

You can test this for yourself by simply being able to measure volumes fairly accurately. On brewday, you have a known quantity of strike water in your MLT. To that you add a known quantity of grain that has a fairly accurate amount of water absorption potential. Subtracting the grain-water absorption amount from the total strike water, you know how much you could theoretically recover at 100%. While draining your first runnings, you should measure how much you can maximally get out. Substracting this volume from the 100% value, you can determine how much wort is being left behind in your MLT. There will ALWAYS be some left behind in the MLT (i.e. the deadspace), but if the value is too large then you are diluting your obtainable sugars on successive runnings which will cause loss of efficiency. A small hit to efficiency is expected, but with poor MLT design, you could potentially be taking a 15+% hit which is significant when you consider that brewing is a lossy hobby and the hits pile up throughout the brewday.