Double Crushing Your Grains For Greater Efficiency

[ScrewyBrewer]

I never double crush and never had a need to. As it is, my grain mill crushes very well and I'm pleased with it.
As for squeezing, I bought some awesome, bright orange 'heat' gloves and I squeeze the snot out of the bags and never had a tannin problem. I don't believe squeezing causes tannins though I have no proof of it causing or not causing haze.

I bought the same colored gloves form Home Depot, it's their HDX brand. They're going to come in handy, no more bare handed cleaning with 140 degree PBW or OxiClean for these tired old hands.

[FedoraDave]

I stir every 15 minutes and think it helps but I recently got a pump and recirc about half way thru.
There's an interesting article in either the latest Zymurgy or BYO magazine that talks about BIAB brewing and how he did some testing on not touching his mash at all, not even to adjust the temperature. He stated (if I remember right) that even if you lost 4-5 degrees in the hour, since about 85-90% of the conversion happens in the first 20-30 minutes, turning the fire on an off only makes things worse or at best, does nothing. Depending on the time of year, I might have to heat up twice in a 60 minute mash.
Just throwing that out there.

Interesting to see the many different processes. When I do BIAB, I single-crush my grains, heat my strike water to where I want the mash temp, stir in the grains, check the temperature once again, and then put the lid on the pot and wrap the pot in three towels and let it rest for 60 minutes. No stirring, no additional heat.

After an hour, I squeeze the bejabbers out of the grains, and put the bag of grains into the sparge water, heated to between 170 and 175. I turn the flame off, stir well, put the lid on, wait 15 minutes, and then squeeze the bejabbers out of it again. Add my first runnings, and wait for the boil.

I'm hitting my numbers consistently, which means at least 75% efficiency, with much less effort than I'm seeing throughout this thread. It ain't broke so I ain't looking to fix it.

[HerbMeowing]

... put the bag of grains into the sparge water, heated to between 170 and 175.

Those sparge water temperatures seem a tad cool to me.
Are they hot enough to raise the grain bed temperature into the upper 160s?

[ScrewyBrewer]

I've been doing a mashout at 170F first then lifting the grain bag over the wort and pouring 170F sparge water over them. It's a process that I'm comfortable with and one that has been giving me great results. That extra 20F really thins out the wort and helps to rinse the sugar from the grains.

[HerbMeowing]

I asked b/c if my grain bed temperature after the 1st running is 150°F ... I need to add a volume of 200°F batch-sparge water to raise the grain bed temperature to 168°F.

Then again ... some claim good results 'cold' batch-sparging works just as well as 'hot' sparging.
Your results seem to confirm the former.

[mashani]

I don't have a mill.

So, for specialty grains I'm using in small amounts I just put them in a zip top bag, and use a rolling pin to bash the *&$*$ out of them. Or for very small amounts (2oz or <), my little coffee grinder.

It works for me LOL.

If I'm doing a PM or AG batch, I buy my grains pre-crushed though. There are limits to my insanity.

[MrBandGuy]

I double crushed for 2 years when I started BiaB. Then my LHBS owner asked me not to do that on his mill, explaining it was a waste of time and somehow messed up the settings. I'm not sure I agree, but turns out it made no difference in my efficiency. I got better efficiency, in fact, by using a larger pot and going full volume.

I heat to strike, mash at temp wrapped in a blanket, then raise to 168 and rest another 10 minutes for a mash out before squeezing and boiling. If I can't fit it at full volume, I will use a second pot to mash out.

[Kealia]

Late to the discussion, but I've been traveling a lot lately.....

I double-crushed when I was BIAB brewing "because that's what I read to do early on" and I never changed my process. Now that I'm using a mash tun, I'm not double-crushing.
So, I had 5 years of double-crushed, squeezed grains in my brewing and have never tasted, nor been told about, any astringency, tannins, etc. as a result. And, I tend to produce pretty clear beers so I've not seen either issue. I don't do step-infusions, so I can't comment on that part.

[Rebel_B]

Never have double crushed; if I have wheat or rye in the grain bill, I will adjust my rollers on my barley crusher a wee bit closer together so that whole pieces don't fall through.

[John Sand]

I use a blender, and produce plenty of flour. Highly roasted grains in particular seem to grind to dust. Very clear beer, no astringency.

[ScrewyBrewer]

I'm going to have to go with myth debunked on this one. Right alongside hot side aeration and other hard to prove brewer lore.