[ultravista]

I mash in a fine mesh bag (voile), as such, don't worry about stuck sparges and I've been wondering if I could improve my extraction efficiency by double crushing the mashing grains.
 
Who here double crushes? What has it done for your efficiency? Typically, what can I epect as an improvement, in points?

[weithman5]

i mash in a bag as well. i don't double crush, but as i do such small batches, i have actually ground my  grains in a vita mix.  i have no problems with stuck sparges, but it has been pointed out that there is some astringency in my beers on occasion

[ultravista]

What kind of efficiency are you getting with the finer crush?

[weithman5]

i still only run around 70  my problems have been temperature control and i have been modifying my system some going electric etc, . it is mostly a consistency issue now as i have also hit 75-80 percent.

[a10t2]

Double crushing will only improve efficiency if the crush was poor to begin with. Is there anything that makes you think you're losing efficiency due to the crush?

[weithman5]

in fact what is your efficiency to begin with.  i would be happy with lower efficiency once i am more consistent with the method.

[ynotbrusum]

Double crushing will only improve efficiency if the crush was poor to begin with. Is there anything that makes you think you're losing efficiency due to the crush?

True, if the crush was poor, but also if the crush was simply moderate.  However, I have gotten a couple extra efficiency points when I have done a double crush, going from 70-72 up to 75-78.  My BC is still at factory settings and used for about 2 years - I may have to gap it soon from "wear".  All that having been said, I am not a commercial brewer, so adding a little extra grain for a single crush is how I typically proceed (cost being a relatively minor issue at this level).

Cheers!

[beersk]

Mashing in a bag you can set your mill gap tighter also, so you don't need to double crush.  My mill is set at .030" and I'm getting 75-80% mashing in a bag.
Don, you shouldn't be getting astringency, must be something going on there.

[weithman5]

beersk, it hasn't been in every beer either. i am not sure. i first detected it as a "tang" kind of flavor. Nateo picked it out as astringency ( I had sent him a few following the faux pils study)  the beer he detected it the most in i had tried to boil in a roaster oven before making the electric kettle.  it took hours to do. and this beer really had corn, rice, a touch of wheat and 2-/6 row.  the beers that he detected it in but to a lesser extent had much more specialty malts that were ground in the vita mix.  i am not yet going to change from this until i try the last two beers this weekend.

[beersk]

Gotcha.  And you brew, what, 1 or 2 gallon batches?  I'm doing 3 gallon batches with mash/brew in a bag method. Haven't done the full volume mash yet, been doing it almost like regular brewing with batch sparging in a cooler, but with two kettles.  Next batch, though, I'm going to try out the full volume thing, like it's intended to be done.

[a10t2]

True, if the crush was poor, but also if the crush was simply moderate.

I should have elaborated, since it isn't like there are standard definitions for this. By a "poor" crush I meant one that's so coarse it will impact efficiency. IME, even a fairly wide mill gap (I keep mine at 30 mil) will allow for 100% conversion.

[malzig]

This is one of those cases where it is helpful to understand your system and know your Conversion efficiency as well as your Mash Efficiency.  In general, improving the crush will only improve Conversion and not Lauter Efficiency.

I saw improved efficiency by double crushing at my LHBC, but I was only getting ~75% Conversion Efficiency from their standard crush, leading to 60-65% Mash Efficiency.  Now, with my own mill, I get 90%+ conversion, so there's little room for double crushing to further improve Mash Efficiency.

A decent rule of thumb, though, is that if you are seeing Mash Efficiencies in the 70's or less on a ~1.050 beer, then you are probably getting poor conversion and your Mash Efficiency has room to be improved by an improved crush (or other changes in procedure).

[philm63]

Improving efficiency can be done by adjusting the crush or double-crushing, sure, but do be mindful the tighter you go or if you double-crush, the more chance of damaging the husks to the extent you'll start extracting tannin.

You may also want to explore "conditioning" your grains - lay the whole grains out on a large flat surface like a counter top, and spritz them lightly with distilled water the night before you crush. This will soften the husks such that when you crush, the husks will slip off more readily and be in better shape should you choose a tighter gap on your mill.

I also do my mini-mashes in a 5-gallon paint strainer bag when I partial-mash, and upon measuring my extract efficiency, I'm hitting the upper 80's to mid-90's regularly BUT - I am pouring my sparge water slowly over the bag suspended in a strainer over the kettle I did the mini-mash in (I do this using 3 or 4 quarts of sparge water from the larger (boil) pot), and then dunking the bag in the remainder of the water in the bigger boil pot - sort of a two-step sparge process that has yielded a terrific efficiency for me thus far. I dunk until the runnings are below 1.015 SG. I crush at the factory setting (0.039) and only crush once.

[weithman5]

Gotcha.  And you brew, what, 1 or 2 gallon batches?  I'm doing 3 gallon batches with mash/brew in a bag method. Haven't done the full volume mash yet, been doing it almost like regular brewing with batch sparging in a cooler, but with two kettles.  Next batch, though, I'm going to try out the full volume thing, like it's intended to be done.

typically 2 gallons.  i put the grain in a bag, and put this in my igloo cooler. i use the electric kettle to heat 4 gallons of water (right to the brim) and what i don't use in the mash i keep in another pot or cooler if needed. then i just drain the cooler back to the kettle to target about three gallons. boil down to 2.25.  ish.  still working some of the kinks out.

[micsager]

Mashing in a bag you can set your mill gap tighter also, so you don't need to double crush.  My mill is set at .030" and I'm getting 75-80% mashing in a bag.
Don, you shouldn't be getting astringency, must be something going on there.

.030"?  Nice.  I recently bought the MM3, and started having some trouble with my OG's.  So, I adjusted it from the factory .045 down to .035 and all is good with the world.  (I just called the two low OG beers "sessions"  LOL