Gap, Crush, and Efficiency

[SEndorf]

Astringency has nothing to do with grind. Tannins come from a combination of high mash/sparge pH and high temps. High temps alone will not lead to astringency.

You are partially correct. Astringency can be exacerbated by oversparging on top of grain too finely milled. Temperature has little effect. But since you BIAB, this isn't much of an issue for you.

Nothing wrong with trying to be more efficient, as long as nothing in the process goes awry because of it.

Agreed. But this thread is in the beginners forum.
I'd suggest concentrating mainly on consistency in the entire brewing process while shooting for mash efficiency in the normal range.
The potential problems from squeezing high efficiency seem to outweigh any potential benefits at this point.
Like I said, nobody has ever cracked open a home brew and said, "dang! this is great! You must have hit 85% on this one!"

 

[attyindaburgh]

So I just got my mm-2, and am getting ready for my maiden all grain brew (not biab). Should I keep it at the factory setting to see how it goes or tighten it up a bit?

 

[IslandLizard]

So I just got my mm-2, and am getting ready for my maiden all grain brew (not biab). Should I keep it at the factory setting to see how it goes or tighten it up a bit?

Congrats, you've joined the MM club. You'll never look back, and probably have to suppress a sneer at anyone milling in the brew store.

That said, I wouldn't trust it or take it for correct.
Use an old credit card (0.032-034") as your gap gauge for barley. A bit narrower for rye and wheat malt and flaked products (0.025-0.028).

Added:
Run some old grain through before your first use. There's a lot of metal, oils, and black stuff on the rollers from manufacturing.
I used rice, which is my oldage mill cleaner, but it is hard and spits out lots of pieces. Wear eye protection.

 

[doug293cz]

You are partially correct. Astringency can be exacerbated by oversparging on top of grain too finely milled. Temperature has little effect. But since you BIAB, this isn't much of an issue for you.

My understanding is that astringency from over sparging is due to the loss of buffering power of the grains as they get rinsed, resulting in a rise in pH. It is the rise in pH that is the culprit. This can be mitigated by using lower pH/alkalinity sparge water. I haven't seen anything that ties the rise in pH with over sparging to crush fineness. Do you have any references? I'm always looking to learn.

I'd suggest concentrating mainly on consistency in the entire brewing process while shooting for mash efficiency in the normal range.
The potential problems from squeezing high efficiency seem to outweigh any potential benefits at this point.

Agreed that it is more important to achieve a decent level of consistency before chasing efficiency. Otherwise, you are chasing a moving target.

Like I said, nobody has ever cracked open a home brew and said, "dang! this is great! You must have hit 85% on this one!"

I have received the comment "this is world class" at a recent party, but I only got 84% eff on the beer that I was serving. I said "thanks, glad you like it." But, efficiency never came up in the conversation.

I strive for consistency and efficiency for my own satisfaction. I want to have a predictable process that I can take pride in. High efficiency does not cause bad beer, poor technique or ingredients do.

Brew on

 

[attyindaburgh]

I'll check with a guage and throw some rice and maybe a little bit of grain to clean it out. I looked Ling and hard before I bit the bullet on the mm. I did opt for the 1/2 " upgrade and the ss rollers so I have the option of conditioning if I want to.

 

[Menhir]

I'm contemplating buying a MM3. Is it worth paying the extra bucks over the MM2?

 

[stpug]

My understanding is that astringency from over sparging is due to the loss of buffering power of the grains as they get rinsed, resulting in a rise in pH. It is the rise in pH that is the culprit. This can be mitigated by using lower pH/alkalinity sparge water. I haven't seen anything that ties the rise in pH with over sparging to crush fineness. Do you have any references? I'm always looking to learn.

Agreed that it is more important to achieve a decent level of consistency before chasing efficiency. Otherwise, you are chasing a moving target.

I have received the comment "this is world class" at a recent party, but I only got 84% eff on the beer that I was serving. I said "thanks, glad you like it." But, efficiency never came up in the conversation.

I strive for consistency and efficiency for my own satisfaction. I want to have a predictable process that I can take pride in. High efficiency does not cause bad beer, poor technique or ingredients do.

Brew on

A much more constructive response than I could have mustered . Good on you!

 

[rodwha]

I didn't do anything to my rollers prior to milling. Hope any oils won't foul my beer.

 

[rodwha]

So I read that since I'm using the old fashioned oats I'll need to cook all 1.5 lbs of them.

Do I drain them?

Can they be cooked the day before?

Do you mix them in with your other grains upon filling the mash tun? Layer them?

Does the cooking water need to be treated?

 

[IslandLizard]

So I read that since I'm using the old fashioned oats I'll need to cook all 1.5 lbs of them.

Do I drain them?

Can they be cooked the day before?

Do you mix them in with your other grains upon filling the mash tun? Layer them?

Does the cooking water need to be treated?

Those are pre-gelatinized through the steam/rolling process. They do not need to be cooked. Run them through the mill for easier dispersion and water absorption. Just mix them in with the other grain.

For those adjuncts that DO need to be pre-cooked, you boil for 20-60 minutes in ample water and dump everything in at the beginning of the mash. Cereal mashing is a similar but notably different process. I would not hold the cereal mash over for a day. That stuff gets solid. Ever seen day old porridge?

No treatment for the cooking water, except for Campden if you use chlorinated water.

Added:
BTW, where did you read they need to be cooked?

 

[IslandLizard]

I didn't do anything to my rollers prior to milling. Hope any oils won't foul my beer.

Your first milling will have cleaned them effectively.

On a scale of things, I'd say the oil and metal contribution is quite negligible. Relax, don't worry.

Call it Steel Mill Porter.

 

[rodwha]

I totally intended this to be a separate thread. Should have started with coffee sooner...

I got this from How To Brew:

"Oats are available whole, steel-cut (i.e. grits), rolled, and flaked. Rolled and flaked oats have had their starches gelatinized (made soluble) by heat and pressure, and are most readily available as "Instant Oatmeal" in the grocery store. Whole oats and "Old Fashioned Rolled Oats" have not had the degree of gelatinization that Instant have had and must be cooked before adding to the mash. "Quick" oatmeal has had a degree of gelatinization but does benefit from being cooked before adding to the mash. Cook according to the directions on the box (but add more water) to ensure that the starches will be fully utilized." 12.2

The oatmeal I am using is not instant.

 

[IslandLizard]

It's your thread...

I know Palmer wrote that and he's a reputable source... mostly. He also wrote that at least 9 years ago, probably longer. Most book revisions usually lack thoroughness and critical editing on existing matter. The consensus on the innuhnet nowadays seems to be that rolled, flaked, quick, and instant oats are all pre-gelatinized by the hot rolling process and can be added to the mash directly (I'd run them through the mill though). Only whole and steel cut oats need to be pre-cooked.

When specifically re-reading that section on adjuncts, Palmer doesn't mention cooking wheat, barley or any of the other flaked adjunct. So why would oats be an exception, except that they come in 6 "different forms," unlike the others. Look at flaked wheat, that looks pretty much the same as rolled or old fashioned oats, don't they?

I eat a lot of oats, raw, cooked with milk, and sometimes in cookies or bread. When cooking "old-fashioned" oats they cook and dissolve rather quickly, like within 5-10 minutes. The steel cut oats take much longer and stay a lot chewier even after 30 minutes of simmering.

Useful hint:
Oats do give a bit more flavor when toasting them in the oven a bit before adding to the mash. So you may want to consider doing that, depending on style.

 

[rodwha]

Mind going into a bit of detail with toasting them?

 

[rodwha]

One of the brackets for the MM2 measured 0.039" and so I think I'll try this as a setting for milling barley. I went ahead and milled my rolled oats and flaked barley using the 0.029" setting the iTunes card gives.

 

[stpug]

Mind going into a bit of detail with toasting them?

Too late now but for future reference. Oats don't bring much flavor to the table in a beer in their "raw" (untoasted) form, but their mouthfeel is generally very apparent in sufficient quantities. If you want to get both the mouthfeel and some flavor contribution from them then you can give them a quick toast in your oven.

The key is to toast them to the point that they get fragrant (smells like cookies are baking) without browning them. It's okay for them to get a little off-white or very light-tan, but you definitely don't want brown. You should also let them breath for at least a couple days after toasting because they will off-gas some weird/acrid smells for a couple days.

Here's how I do it:
-Preheat oven to 300-325F
-Spread oats in thinnest layer you can on cookies sheet
-Bake for 30min
-Stir every 10min
-When you pull them out I find it best to quick cool them in freezer for just a couple minutes to cease the cooking process
-Let them air out for 2-7 days (the darker toasted the more time needed)

Edit:
I also find it easiest to "mill" my flaked grains "by hand" so I don't have to both adjusting my mill. I simply grab a half-handful at a time and crunch them up into my milled grains

 

[rodwha]

I had milled these with a pound of flaked barley on my 0.029" setting.

I see you mentioned a shorter resting period. I will be brewing this on Thu. I would have time to allow it to sit.

You also mentioned not browning them. Maybe this is why they required 2 weeks to sit? Because of reading many cases of such I had decided not to toast them. Reading this is making me reconsider.

 

[rodwha]

I have 1.75 lbs of oats and 1 lb of flaked barley. It may not end up as thin of a layer, especially after having been milled, but I'll try it.

With so much it looks link I'll need to do it in waves too.

Can I fill up kid's lunch bag paper sacks or is that too compacted?

 

[stpug]

I had milled these with a pound of flaked barley on my 0.029" setting.

I see you mentioned a shorter resting period. I will be brewing this on Thu. I would have time to allow it to sit.

You also mentioned not browning them. Maybe this is why they required 2 weeks to sit? Because of reading many cases of such I had decided not to toast them. Reading this is making me reconsider.

The resting time is something I've noticed is proportionate to the toasting level. The darker the toast, the more rest is needed. If you do a light toast then a couple days is sufficient, IMO. Lightly toasted oats may not look much/any different than when they went in, but they WILL taste different. I would definitely recommend starting at the lightest end of toasting and working your way darker in future batches.

I wouldn't toast milled oats or quick oats because the particle size is inconsistent and you're likely to end up with some pieces toasting too much/quickly and causing acrid flavors in you beer (particularly since you've already milled them with grain). It's the case of "one rotten apple will spoil the bunch". Save the toasting for a future batch.

The actual TASTE of the toasting is significantly more that what your eye sees. In other words, don't judge the level of toasting by simply looking at them because the taste is what matters. If you see "brown" then toss them out and start again

 

[LandoLincoln]

When discussing grain mills and gaps and efficiency, one really should be talking about mash efficiency instead of overall brewhouse efficiency, since boil kettle deadspace and tubing and all of that has nothing to do with how well your grain mill and mash tun are doing their job. Just saying.

Anyway...I have a MM2-Pro and I have my mill set at .035 and I'm getting around 93% mash efficiency.

 

[rodwha]

I had just set them on their 3rd round when I read the response. I pulled them and set them in paper bags in the freezer. It had begun to smell lightly of cookies earlier.

 

[rodwha]

Lando: The reason I will readjust the gap is due to the incredibly slow sparge. Since flaked oats and rolled oatmeal is fairly thin I figured the tighter gap was good.

My OG reading on my black ale was 4 points higher and I certainly didn't get all of the wort out. It's hard for me to figure an accurate efficiency as I partial boil, and this latest beer used 4 lbs of LME. But it was well above 80%.

 

[IslandLizard]

I think your toasted milled grains will be fine, as long as they smell fine. Taste some. Stpug is right, toasting goes beyond what meets the eye, so timed intervals are your best bet for consistency. I put 3 trays in the middle of my convection oven to lightly toast grains and adjuncts that can benefit from it. Turning is the messy part, can't shake and flip them like a skillet (yet).

Airing out goes faster when spread on a tray rather than in a paper bag, not?

 

[rodwha]

What is the point in keeping them in a paper bag?

They didn't look any different as far as I could tell, but did smell a little like oatmeal cookies. I'm really looking forward to this!

Can't wait to do it right with an oatmeal pale ale though...

 

[stpug]

I think the paper bag is just a permeable container to allow gasses to escape but keep dust and other sh!t out. Leaving them open on a tray is fine also if you plan on using them soon (within a couple days) and are confident you won't have roaches and mice crawling through them. Eventually it's all gonna get boiled for an hour anyways

 

[govner1]

I received a MM2 for Christmas. It came preset at 0.045", which seems a bit wide from what little I've read. It seems many set it to 0.030" or about a credit card width.

I checked my used iTunes card and found it to be 0.029" according to my calipers. If I'm conditioning my grains prior to crush will this be just a bit too narrow?

And how will it behave when crushing wheat (I use a lot of soft white wheat berries)?

I've adjusted it to iTunes card width now, and so without feeler gauges I'll not be able to set it properly to another setting, though I had considered that I could just loosen it a touch and call it close enough for now if this is too tight. Or maybe I can find something around the house that's a better width.



I've yet to try conditioning grains, but I'm not too concerned with a slow sparge (I BIAB using a large colander) if it ends up tearing up the husks more than ideally.

I must say that I am anxious to give it a go! I'm also looking forward to the freedom crushing your own grains gives.

I have a 3 roller MM. I originally had it set at .029 but after some experimentation I found that .031 gives me an ideal crush.
Once you get your gap set mark the adjustment knob(s) & the surface next to it so you can easily see if you've gotten out of adjustment.

 

[rodwha]

I keep forgetting to add a scratch awl to my Home Depot list, as it seems the best idea for at a glance figuring.

 

[rodwha]

Used to have a rat, but no cockroaches or mice. He would have loved it had I left that out! Used to store all kinds of stuff!

Spreading them out a bit makes sense especially since they've been milled. I'll go that route for a while using wax paper or something.

 

[lhommedieu]

I use a MaltMill from JSP. One side is fixed and the other is adjustable. I got a set of spark plug gap gauges (feeler gauges) from Amazon and can adjust the gap in the middle to where I want it. This is useful as I might want some grain to have a higher or lower percentage of flour.

You can invest in a set of grain sieves that will break down the percentage of grain according to size, but these are somewhat expensive and I can't justify the cost just yet.

 

[Owly055]

The one aspect of "efficiency" resulting from a fine grind that nobody seems to mention it the additional trub.

The story that astringency or poor / undrinkable beer goes hand in hand with efficiency is absolute bunk.

We need to redefine efficiency as ounces of good beer per pound of grain............ NOT OG points per pound of grain.


H.W.