36% brewhouse efficiency...Tipped it out

[SMOKEU]

I have a Robobrew 3.1 with pump and usually get a 70-72% mash efficiency.

Today I did my first wheat beer with 59% wheat malt, and the rest barley malt. I only got 36% BH efficiency for some reason.

I added 500g of oat hulls. While doing the recirculation, I noticed the mash water was flowing through the grain bed much more quickly than usual. For most brews I have the recirc valve about 1/3 of the way open but this time I had it fully open and it still didn't flood the grain bed as usual.

I did my ferulic acid rest for 15 minutes at 44C/111F, then the saccharification rest for 60 minutes at 67C/152F before mashout.

I also needed much more sparge water than I thought but that still doesn't account for that mash efficiency...

 

[RPh_Guy]

Maybe the wheat wasn't milled properly? Often it requires a smaller mill gap.

 

[RM-MN]

Wheat kernels are both smaller and harder than barley so they need to be milled finer. If you didn't adjust the mill to take this into account the wheat didn't really get crushed.

 

[SMOKEU]

I spoke with both the maltster (who also suggested it's something to do with the crush), and the brew shop owner (who doesn't think it's about the crush).

The grains are milled to 1.45mm. The pic below is what the brew shop sent me of what the grains look like after he's milled them.

I went back to the brew shop and ordered the same grains but this time asked for them to be double milled. I'll try again tomorrow.

 

[bracconiere]

damn, i really want to post a joke thread in drunken ramblining....but my crapy camera doesn't have good enough resolution to get how fine i crush.......


i'd barley call that cracked wheat......

 

[RPh_Guy]

I agree the crush looks pretty bad in the photo.

 

[bracconiere]

you want the whole thing to look like what i circled.....

 

[IslandLizard]

The grains are milled to 1.45mm.

That's a sad efficiency!

Gap width: 1.45 mm / 25.4 mm/inch = 0.057"
That's a very coarse crush, even for barley.

For comparison, I mill small kernel grain such as wheat and rye separately from barley, at a 0.026-0.028" gap, less than half of your brew store's. Oats even tighter.

Even sending them twice through the mill won't help much, most will drop right through, mostly uncrushed.

 

[bracconiere]

Gap width: 1.45 mm / 25.4 mm/inch = 0.057"

thanks for doing, what i assume is accurate math....i crush everything at 0.028", gives me a lot of flour....but even with my bazooka tube i don't get stuck sparges, even with 1/3 whole wheat berries...speaking of which i need to keg it tomorrow.....


0.057" seems more like trying to stroke it without getting blisters on your palm.......no pay dirt at the end.....lol

 

[IslandLizard]

I've read you can grind grain in a blender. I've never tried it.

You really need to pulverize that wheat quite a bit more. Maybe use a hammer?
A Grainfather is a BIAB(asket) system, you can mill quite fine, but not as fine as when using a nylon bag. You need flow through the grist for your mash recirculation. Rice or oat hulls help with keeping it lush (permeable).

 

[bracconiere]

Maybe use a hammer?

LOL, a rolling pin or scuffed up pasta roller would be better then 0.057"?

 

[SMOKEU]

Does this look any better? That's after a double crush on the same roller.

Keep in mind this does have oat hulls in it.

I don't have a rolling pin or blender unfortunately.

I don't want to have to throw out all the grains as I don't see how else I can crush them properly.

 

[SMOKEU]

I put the grains in a bucket and tried crushing them with a glass bottle. Epic fail. I did mix the oat hulls properly in this time so take a look at these pics after my crush attempt...

 

[SMOKEU]

Also, this may make for some interesting reading, straight from the maltster themselves:

"I measured our pilot brewery’s 2 roller mill now you have a size to go by. The measured gap is 1.45 mm (0.057"). We have set our mill to reflect our malts plumpness and never had any issues with runoffs or stuck mashes.

...The average size of our malt grain is >2.8mm (0.11") for barley and wheat.

Gladfield Malts are consistent in size. We screen our malts on a 2.5 mm (0.09") screens which not many maltings around the world do. Most maltings de-culm the malts but not screen it. Hence our malts are free of dust, sticks and small grains. "

https://www.gladfieldmalt.co.nz/mill-gap/

 

[RM-MN]

If you intend to brew more wheat beers now is the time to invest in a Corona style mill. It will mill those wheat and rye kernels to a much smaller size. That smaller size increased the mash efficiency and reduces the time required for conversion. Here's an example.

https://www.amazon.com/Premium-Qual...=1&keywords=corona+mill&qid=1589536418&sr=8-2
Note that the cost of the mill is less than the cost of the grain for the batch you just discarded. If you have the storage space, buy full bags of the grains you mostly use and pay for the mill again in cost savings.

 

[RM-MN]

"I measured our pilot brewery’s 2 roller mill now you have a size to go by. The measured gap is 1.45 mm (0.057"). We have set our mill to reflect our malts plumpness and never had any issues with runoffs or stuck mashes.

Good response from the maltster. To me is says we set our mill way too big in order to accommodate those brewers with bad systems so they never get stuck mashes and since their mash efficiency will be really low we get to sell them more grain to compensate which realizes us more profit.

 

[SMOKEU]

Would it even be worth attempting to mash the grains in the pics above (the pics where I'm holding the grains in my hand) or should I just throw it out? I really don't want to waste half a day (again) with something if I know it's not going to work.

If you intend to brew more wheat beers now is the time to invest in a Corona style mill. It will mill those wheat and rye kernels to a much smaller size. That smaller size increased the mash efficiency and reduces the time required for conversion. Here's an example.

https://www.amazon.com/Premium-Qual...=1&keywords=corona+mill&qid=1589536418&sr=8-2
Note that the cost of the mill is less than the cost of the grain for the batch you just discarded. If you have the storage space, buy full bags of the grains you mostly use and pay for the mill again in cost savings.

I really am keen for a mill! But the problem is that shipping to NZ usually costs far more than the mill itself. The cost of living in a small island nation on the bottom of the world.

Good response from the maltster. To me is says we set our mill way too big in order to accommodate those brewers with bad systems so they never get stuck mashes and since their mash efficiency will be really low we get to sell them more grain to compensate which realizes us more profit.

It just seems sad that I can't trust anyone in this industry any more when it comes to milling grains properly even when I specifically mentioned it's a BIAB system I'm using.

 

[soccerdad]

Mash overnight with your current grain as it is

 

[TheMadKing]

I'm going to chime in and say, I agree that your crush is too coarse, but I think your main issue was mash channeling.

Don't recirculate with your valve wide open ever, and stop recirculation and stir your mash every 10-15 minutes with that much wheat in there.

Recirculate as slow as possible while still able to maintain mash temp.

 

[RM-MN]

I agree with Soccerdad, do a long mash. I might only do a 2 hour mash but it won't hurt to do an overnight either.

 

[Carolina_Matt]

What kind of wheat did you buy? I tried recreating a recipe from Morebeer, so I bought the individual components. For 'Wheat', I didn't know which one to choose so I got raw wheat. My efficiency was horrendous.

 

[IslandLizard]

Would it even be worth attempting to mash the grains in the pics above (the pics where I'm holding the grains in my hand) or should I just throw it out?

Don't throw it out! It seems to look somewhat (but marginally) better. I don't see whole uncrushed kernels.

The coarseness<>fineness of a crush that's perfect (or at least adequate) depends on your mash and sparge system. Most commercial micro breweries use a mechanical way to agitate (rake) the mash in the mash tun during the entire time. They get complete conversion in 35-45 minutes, at least that's what's being claimed. Then it gets lautered and fly sparged. Sparging/lautering is an integral part of mash efficiency to rinse out the sugars trapped in the wet grist.
So 2 processes are important to obtain decent mash efficiency, first conversion, followed by lautering/sparging.

Mash and sparge methods dictate the level of crush needed. With BIAB the grist can be much finer than in other systems due to the fine filter, a nylon bag or fine mesh basket, resulting in faster conversion and higher mash efficiencies.
Now a Grainfather (and alike systems) are again different from typical BIAB, as the basket isn't submerged in a kettle with water/wort, there's a recirculation system. Neither BIAB systems typically incorporates sparging, although some brewers may squeeze, pour over water or dunk the grist filled bag or basket in a bucket with water to eek out more of the high gravity wort that's trapped within. Volumes need to be adjusted to end up with just the right amount of pre-boil wort.

Good pointers were given, finer crush, longer mashing, and/or slower recirculation. Perhaps some sort of sparge once conversion has been optimized for the grist mixture at hand.

 

[SMOKEU]

What kind of wheat did you buy? I tried recreating a recipe from Morebeer, so I bought the individual components. For 'Wheat', I didn't know which one to choose so I got raw wheat. My efficiency was horrendous.

Gladfield wheat malt.

 

[SMOKEU]

I tried again, but even though I ordered 200g (barley) acid malt the mash pH was way too high - after the 10 minute ferrulic acid rest and 15 minute saccharification rest, the pH was at 6.3. I tipped the wort out.

That's 2 throw away batches in a row now.

 

[TheMadKing]

I tried again, but even though I ordered 200g (barley) acid malt the mash pH was way too high - after the 10 minute ferrulic acid rest and 15 minute saccharification rest, the pH was at 6.3. I tipped the wort out.

That's 2 throw away batches in a row now.

You dumped a batch because your mash pH was too high?

Definitely not a reason to dump

 

[SMOKEU]

You dumped a batch because your mash pH was too high?

Definitely not a reason to dump

At what point would it need to be thrown out at in terms of mash pH after that time?

I just bought a pre-milled all grain kit in a box and mashed it with the same method as I did for the wheat beers. With 2mL lactic acid (that was a wild guess) I hit mash pH of 5.6 straight away (after 10 minutes of mashing in a couple of minutes recirculation) and hit my mash efficiency too, so I don't think it's my equipment or method since all-barley mashes don't seem to cause an issue. These grains appeared to be milled more fine than I've ever used, and the grain bed was draining slower than I was used to but I didn't have a problem.

I think I'll have to give up completely on wheat beers until I can afford my own grain mill.

 

[SMOKEU]

I emailed another local brew shop - and again, their mill gap is the same 1.45mm (0.057"), even for wheat!

 

[bracconiere]

i just did a batch of wheat beer....my ph was high too....but i just added epsom salts to lower it.....

At what point would it need to be thrown out at in terms of mash pH after that time?

when your OG gravity makes it not worth fermenting to drink? but still then could be good kombucha!!!

 

[IslandLizard]

I emailed another local brew shop - and again, their mill gap is the same 1.45mm (0.057"), even for wheat!

Brew shops are not going to change their mill gap. Expecting or even asking that is a pipe dream. Some won't even run it through more than once.
The 70-72% mash efficiency you get with barley is already an indication something is off with the milling.

Either start looking for your own adjustable mill or learn how to deal with their overly coarse crush.
If you can buy bags of base malt directly from the maltster and mill your own batches, you may save enough money that repays your mill investment. Most of us use 2 roller mills, running US$100-200.
A knock off Corona mill may run US$25 (e.g., AliExpress) and do a wonderful job with the right adjustments. Use a drill to motorize, or some other motor.

 

[IslandLizard]

I tried again, but even though I ordered 200g (barley) acid malt the mash pH was way too high - after the 10 minute ferrulic acid rest and 15 minute saccharification rest, the pH was at 6.3. I tipped the wort out.

That's 2 throw away batches in a row now.

Use mash water calculator to estimate acid additions. I like BrunWater. Free edition is fine.
You really should measure mash pH at the end of the mash to get a valid reading. Make sure you get a representative sample. And chill it to your pH meter calibration temp or thereabout.

Or do a small 1/2 - 1 pound test mash of your grist mixture (measure each ingredient accurately), to get the real pH. Adjust your main batch acid additions accordingly. And add that test mash to your main mash, at the end.
No wort left behind!