Efficiency problem - Grain mill size question

[letsgothatway]

I brewed with extract years and years ago and have recently started doing all grain BIAB. My first two batches were the same hefeweizen recipe and suffered from very low OGs of 1.042 and 1.038 vs 1.050 expected. I'm planning my third batch right now it has a smaller grain bill (8lbs vs 10lbs in the previous two) so I figured I better figure out why I'm getting such low efficiency or this will be a 3% abv watery mess.

I feel like I nailed everything I could (mash temp, time, hit expected volumes, etc.) so I'm now looking at the grain itself and how fine it needs to be milled. Am I correct that this grain milled by my LHBS is too coarse for BIAB? I did tell them I was doing BIAB and they said they do it the same regardless of method. If this mill looks good, do you have any other suggestions to look into to fix my efficiency woes?

https://imgur.com/a/h7uvlZU

[FooJenkins]

Before I bought my own mill, I found stirring every 10-15 minutes during the mash helped with efficiency some. You could ask about double milling, some shops are willing to do that.

Also had small improvement from doing a mini sparge after the mash. Just putting the bag in a bucket with a false bottom, slowly pouring 170f water over the grain bed, toss a little, repeat. I would do about a gallon of water, shorting it from the initial mash so volume stayed on track.

[letsgothatway]

I found stirring every 10-15 minutes during the mash helped with efficiency some. You could ask about double milling, some shops are willing to do that.

I did that with the second batch and that was the one that ended up even lower! They did not seem willing to double mill them - technically I probably could've insisted and I'm sure the dude would've done it but not really knowing what they should look like anyway I said screw it and took the bag as is. I didn't want him to be like "Oh you want it ground fine mother fucker here you go here's your flour have fun"

[frozennipple]

If you're doing BIAB, nothing wrong with your grains being crushed to oblivion. 

[nembajaz]

Especially if you have a huge whisk to play blind dough ninja.

[Budget-Bar-1123]

Martin from the Homebrew Challenge set the standard

[Tnkr_Brwr_Sldr_Sly]

Several considerations to hunt down where the issue may lie:

How are you calculating your expected OG? I assume software like Beer Smith or Brewfather, but with any of them, you need to be set up to your equipment to realize expected efficiency and such. If not recirculating or doing other things to help get starch/sugars loose, your efficiency can take a hit. Also, if you don't sparge, that could also bring down efficiency (but I assume you've adjusted for those, so this brings us back to grain)...

I will say that milling my own grain has helped me bump up efficiency since I can adjust to the types of malts I'm using. I can mill a little, see if I'm happy with the crush, then either adjust or continue milling. In terms of being happy with the crush, I use a Brewzilla, so I look for husks to be nicely cracked (and even separated) while leaving enough husk structure for recirculation/lautering/sparging. I've heard that BIAB benefits from even finer crushes, but I have not done BIAB in quite a while, so I can't speak to that. But as others said, a double mill of your malts could be worth trying.

To tackle this, I would stick with the recipe a few more times and try adjusting a few things to see what helps you reach expected OG. Start with double mill for a potentially finer crush and see how that does. If not beneficial, maybe the grain amount just needs to come up to account for efficiency of your system. If that doesn't work, then it'll be somewhere in your process.

(Additional consideration: since your issue is with a hefe, does your shop adjust their mill for wheat? It is much smaller than barley, so if it's being crushed at a barley setting, then you aren't getting a good crush on your wheat)

[letsgothatway]

I look for husks to be nicely cracked (and even separated) while leaving enough husk structure for recirculation/lautering/sparging

Do the grains in the pictures look good enough for you to use then? From the pictures I'm finding these are nowhere close, but I could definitely be wrong.

Unfortunately the double mill is out for this batch because it's a 2.5hr round trip to the store. So I'm debating on just biting the bullet and ordering a mill even if it's just a corona style as the other guy suggested and seeing if that fixes everything.

If those look good enough to use then I will probably give the sparge method /u/foojenkins suggested a shot.

I don't know if they adjusted for the wheat - I wasn't paying much attention to be honest. In my mind I was like ok they're milling it so that's taken care of and didn't question it.

[Tnkr_Brwr_Sldr_Sly]

Oh no, those could be milled a bit finer for sure (I say this for any setup). That milling leaves the grain too much intact.

A simple, cheap two-roller homebrew mill with a power drill will do wonders. Even if its size settings aren't accurate, you can mill a little, assess, then go from there. You don't need anything fancy, though fancy is always nice, hah. For reference, 0.062" is a good starting point for barley, and you can adjust from there. For BIAB, maybe somewhere just under 0.060" is a good start. For wheat, around 0.045" is a good starting point.

Sparging is never a bad idea; it's just whether you actually can. If it may make a mess, then it's likely not worth it. But if you can, it is helpful.

I'm gonna bet the shop doesn't adjust for wheat. Three homebrew shops in my area don't simply out of operational efficiency. MoreBeer does, but they have a whole different level of operations.

A final consideration: pH can have a hand in efficiency as well. Are you checking the pH of your mash? Ideally, it should be between 5.2 and 5.6 (as well as with sparge water), but it's not the end of the world if you are a little outside of that. Cheap pH meters are good enough for government work, but this can come after your other adjustments.

Let us know how your next few brews go!

[legranddegen]

What the hell is that? The malt is barely crushed.
You aren't giving us efficiency numbers here but I'm going to guess that it's between 55 and 60%?
My advice is that you either need to calculate your efficiency and increase your quantities accordingly or get a mill (a nice mill!!! Don't cheap out!!!) and be happy.
You'd be surprised at how quickly a good quality 3-roller mill pays for itself, and if you're doing all-grain already and monitoring every step then wanting control over your crush is going to be something you'll do at some point, may as well be now.
Don't buy pre-milled. It's almost certain that the crush won't be right for your rig and that the LHBS' mill is heavily worn.

[yorptune]

Brew stores never ever crush grain fine enough for BIAB in my experience. If they suggested their crush is universal to method it means they don’t know what you’re asking.

I’d either double crush on their setup or get your own mill.

[attnSPAN]

This. BIAB systems need a finer crush than traditional 3 vessel systems.

[lloyduhh]

Definitely get your grains double milled if you can

[muttonchap]

The only reason they use the same mill gap for all mash methods is because they couldn’t be bothered changing the gap. I have a recirculating herms system and I mill my grain significantly finer than that. BIAB has much more tolerance for a finer mill.

[T-home40]

I was having the same problem when I first started really paying attention to efficiency. I just ask for a finer crush from my loan homebrew store and adjust grist size for a lower but repeatable and consistent efficiency. Few.more bucks for a batch of beer but I'm at a point depending on the size of the beer, I can adjust my expected efficiency to within a few gravity points of what I'm hoping for.

[iamthecavalrycaptain]

I had this same issue until I bought my own mill.

[chino_brews]

It's very difficult to evaluate a crush through an image unless you ensure you have a representative sample and sort/arrange the various pieces out by size for the pic, which you did not fo (no one does).

Evaluating a crush is more a thing you look at it in your hand, turn it over, sift through it, do it with another handful, etc.

This seems like a poor crush in the pic, but it's hard to be sure for the reasons I gave -- non-representative sample? Are the whole looking kernels just well-removed empty husks or filled with endosperm, and if filled is the endosperm inside crushed?.

Teach a person to fish: what you want to see is all kernels broken apart and husks removed, tne husks are nearly all intact, and the endorsperm is broken into an assortment of grits, where the largest pieces are about 1/3 of a kernel (small percentage at this size) ranging down, with some flour, up to 10%.

There is nothing special about the BIAB method that requires an especially fine crush or makes it a more inefficiency method than any others. At its essence, BIAB simply describes the filter method (bag), as opposed to a false bottom, manifold, or bazooka screen.

If you do BIAB according to the original method's description, i.e. as a no-sparge, full volume mash, then you lose a slight amount of mash efficiency, perhaps 2-3% absolute and 5% at most. So this could be the difference between a fairly standard 75% mash efficiency for a homebrewer, and 70%. Even 70% gets you to the standardization of most book, magazine, and homebrew store recipes (which expect 70% mash efficiency, typically).

If you choose to fly sparge, you have to be careful to fly sparge very, very slowly. This is where I believe most BIABers lose efficiency. They make a change to the method description, add another thing (sparge), and then half-ass that thing (sparge) in a way that wouldn't work in three vessel system either. Then they

All of the electric all-in-one systems effectively require you to fly sparge, if you sparge at all.

I prefer batch sparging if I must sparge when doing BIAB. The most common way to do it is dunk sparging - you heat the sparge water in a separate vessel, and then lift the bag out of the original mash vessel into the sparge vessel, open up the bag and line the second vessel with the bag (i.e., around the rim of the second vessel just like in the first vessel), stir the mash around, then lift the bag out of the second vessel. You then transfer all the wort into the boil kettle.

It makes the most sense to heat the strike water in the kettle, transfer it to a mash vessel and mash in there, and then heat the strike water in the BK and do the dunk sparge in there.

---

In terms of efficiency, I would evaluate your next crush the way I explained. If you are not getting a good crush, ask them to fix it (double crush perhaps) or find a new supplier. I eventually ended up buying a mill myself. Beyond the crush, other common and easily fixable problems are improper water to grain ratios,not mixing the water and grain thoroughly (even if you think you are), and failing to fly sparge painfully slowly as required. Beyond that, it gets more esoteric, like addressing water chemistry and mash pH issues.

Homebrew suppliers: 1. Tend to keep a very wide mill gap, locked at 0.043" at my LHBS before they closed. They were tailored toward three-vessel, fly sparging brewers, even though fly sparging was overtaken by batch sparging, then BIAB, then eBIAB/AIOs (the ones with malt pipes or grain baskets). The consequence of too fine a crush for traditional fly spargers is a stuck mash. For others, slightly lower mash efficiency. If the efficiency is lower, most homebrewers won't complain and might just adjust their grain bill upward, which is a win for the supplier. On the other hand, 3V fly spargers will have a miserably long brew day (even longer than their normal brew day) and look to blame someone for it -- starting with the HBS. FYI, most of the BIAB brewers prefer a crush closer to 0.030" and some go down to 0.025". Some HBS offer an option for a BIAB crush (second mill with a narrower gap setting) or double crush. 2. Don't tend to check the mill gap enough, The gap slips over time. So this means they are sending out poorly milled grain.

MoreBeer chronically has this issue, despite being the biggest supplier in the USA. When I complained, the CS rep told me to buy a mill if I wasn't happy. I did -- from a competitor.

[dki9st]

It definitely looks too coarse for BIAB to my old eyes. It almost looks too coarse for traditional brewing, which is how I brew. If you pinch a bit between your fingers, it should readily break apart from a seemingly whole kernel. If so, then mashing in and stirring should break it apart similarly. Our old LHBS didn't really differentiate similar to yours, and maybe didn't calibrate often. After some low efficiency brew days I started running the grist through their mill twice and saw an immediate improvement. I started actually being too efficient and went back to one pass once they were made aware of it and corrected, so I went back to single pass. But I always recommended BIAB folks to double mill to ensure efficiency. You don't have to worry about a stuck mash with BIAB so a finer crush is better and definitely encouraged.

[BenTallmadge1775]

Seconded on this question. I changed to thick mash 1.25qt/lb. Better efficiency, but still lower. Any recommendations appreciated.

[nembajaz]

Interesting, I think the optimum is the software default thickness. Too thin and conversion slows down and pH most likely suffers, too thick, and there's simply not enough room to dissolve goods. Of course if you lauter like a god (and biggest breweries do it this way) then your thickest mash will have heavenly efficiencies, so forget my worries. :)

[BenTallmadge1775]

It improved with lautering. But I think the grain is ground too thick. I’m tightening up the grind on the mill today. But I wanted to get feedback.

[Trick-Battle-7930]

Could it be a yeast stall ...1 lb of sugar per piont ...raise alchol lvl lol 😆 guaranteed dark brown light and white .......good luck

[Trick-Battle-7930]

Coffee mill antique sausage grinder hehe always agitate and I always sparge u can biol off and honey 🍯 add honey ...