Grain conditioning ruined my efficiency?

[ChrisPDuck]

Hi all
Fairly new to brewing but I’m now producing some consistent and good brews on my grainfather.
However in my eternal quest to ‘improve’ my technique I seem to have tacken a couple of steps back.

I have been consistently getting between 85% and 89% mash efficiency but decided to try a couple of additions to today’s brew day which resulted in a mash efficiency of 67%

Firstly I used a Campden tablet to remove any chlorine and chloramine from the water. I don’t see this was the cause but mension it as it’s something I haven’t done before. I used half a tablet in the 18.5l of mash water and half a tablet in the 15l of sparge water.

Secondly I tried grain conditioning.
I used 112g of water for my 6.5Kg of grain, finely misted over while giving a good mix.
Left it for 15 minutes then milled it on at my usual spacing, it’s here I think I may have messed up. Should the grain be milled finer after it’s been conditioned?

Grain came out like this

And looked like this after mashing

Any thoughts?

I must add the flow was awesome, even with the valve for the pump fully open it didn’t reach the top of the overflow attachment.

 

[An Ankoù]

The campden tablet won'[t have effected efficiency in the slightest. Just looked at this site to see what grain conditioning is supposed to be:
https://www.homebrewsupply.com/learn/wet-milling-conditioning-grain.html
Seems a mighty faff for little return to me! If you're a big brewery trying to maximise potential then I suppose it's worth the effort- especially if it's mechanised.
I can only suggest that improved run through means you need a much slower sparge, but how to do that with an all-in-one is beyond my ken.
Anybody else tried this?

 

[ChrisPDuck]

It was more for to reduce slow/stuck mash than the boost in efficiency.
It took maybe 5 minutes, really very little effort so thought I’d give it a go given the potential benefits

 

[Norfolk79]

Reading this and I was getting a feeling of dejavu. Tried conditioning my grain for the first time last weekend just to give it a try and the same happened, although my efficiency dropped to about 78% from the high 80’s. Ended up undershooting my target gravity by 3 points.

Did wonder if the grain needed milling a bit finer if it’s been conditioned.

Will be going back to my crushing the dry grain again next brew.

 

[Oneflewover]

I've tried grain conditioning, was quite pleased with the results. The husk stays intact so you can mill finer. Results in a good filter bed and helps with recirculation and sparging. I reckon you haven't milled fine enough

 

[foxy]

It does look like you have unbroken grain in the mash, why did you decide to condition? Have you had problems milling the grain dry?

 

[Oneflewover]

From Brewers Friend:

"Why would a brewer care to leave their grain husks more intact during the milling process? There are several reasons that would lead one to consider malt conditioning:

• Pulverized husks can lead to tanning [sic] astringency in beer
• Intact husks will create a more free flowing grain bed (fewer stuck sparges)
• You can crush finer to increase conversion efficiency without shredding husks"

 

[An Ankoù]

Certainly there's got to be something that makes it worthwhile if some commercial breweries do it! I see that step of the homebrew supplies.com method (link above) says crush like normal- this is clearly wrong based on what Oneflower and others are saying.
As a matter of interest, 90% of my malt comes pre-crushed (only Brouwland don't mill the grain) and I rarely, if ever get a stuck mash. I wonder if you're milling too fine.

 

[foxy]

In the first picture there is definitely grain which hasn't broken which explains the loss of efficiency, maybe you should have adjusted your mill for a finer crush. Grain with to much moisture content will simply just go through the mill without cracking and releasing the fermentable sugar trapped inside.

 

[Zephyr259]

You're hitting similar mash efficiencies as I am, and this brew hit similar to a recent brew where my grain didn't mill properly and I had a bunch of uncrushed grains. Like you said, great circulation and run off, but terrible efficiency. Never tried conditioning myself but I guess a finer mill setting would be helpful. Good luck.

 

[xozzx]

What crush sizes is everyone using with GF? I am currently at 0.9mm and getting better efficiency. With a big grain bill I am getting very slow sparge but this is to be expected.

 

[Zephyr259]

Probably about the same but haven't measured it, originally credit card width to start with then went a touch finer then a touch coarser. I slide a kitchen knife into the gap and have an idea where it should start to catch.

 

[ChrisPDuck]

Just bought some feeler gauges to measure properly (used a card before).
Turns out I was 1.0mm one side and 1.1mm the other.
I assume this is much too big for conditioned grain. Have gapped it to 0.85mm, will give that a crack on the next one and report back.

Shouln’t have tried something new with such a nice beer really, was looking forward to it. ‘big smoke’s Underworld Milk Stout’ https://www.bigsmokebrew.co.uk/new-page

 

[foxy]

Just bought some feeler gauges to measure properly (used a card before).
Turns out I was 1.0mm one side and 1.1mm the other.
I assume this is much too big for conditioned grain. Have gapped it to 0.85mm, will give that a crack on the next one and report back.

Shouln’t have tried something new with such a nice beer really, was looking forward to it. ‘big smoke’s Underworld Milk Stout’ https://www.bigsmokebrew.co.uk/new-page

Just try a couple of hand fulls first, just in case.