Will milling my own malt improve efficiency?

[Birdsnestbrewery]

I have had a couple of lower than expected OG brews recently and wondered if it's related to the 25kg bag of maris otter I am using. Googling for mash efficiency, one common piece of advice is to get a mill.
Is it really worth it, or are these likely to be instances where they don't have access to well-crushed malt?

 

[RichardM]

Having your own mill allows you decide how finely or coarsely to mill your grain. That may or may not increase your efficiency, depending on where you are starting from and which direction you go re crush size.

A cheaper, simpler option would be to use a bit more grain.

 

[DocAnna]

It depends ….

Milling your own grain gives you control so you may benefit from a finer milling, or it might just cause everything to stick and slow the sparge down and worsen your efficiency.

Personally, the primary benefit of milling my own grain is being able to buy whole grain malts which keep better for longer. I can also mill differently for different sizes of grains to get the best out of them. My efficacy from todays brew day wasn’t good, but that was more to do with it being a large grain bill and low volume sparge. On the whole, your efficiency will drop with larger grain bills and stronger beers - far more significantly than the milling grade.

 

[The Baron]

The answer is yes it will as the reasons Anna has said, however it depends on how important BH Efficiency is to you.
I personally do not bother chasing it anymore as long as I get a reasonable Efficiency.
It is much easier to add a little more grain if you have a downturn in Eff in your last couple of brews, it could just be a different brand/type of grain you have bought or that you may have to look at your brewing process and may have inadvertently changed something that you have not noticed.
If you have dropped a lot in Eff then look at the grain, crush and process but it will not affect your beer too much just a little less ABV.
Ps you could always do a small mash in a pan to add if you are worried of it dropping the body of the beer too much

 

[Agentgonzo]

Efficiency is just a number at the end of the day. At the homebrew level, adding a bit of extra grain to hit your target gravity costs pennies

 

[Birdsnestbrewery]

Thanks that pretty much confirmed what I thought. It's not so much chasing efficiency for its own sake, rather that it has dropped recently.
I will do some experiments with small mashes and see what I can figure out.

 

[Stu's Brews]

Whether it improves efficiency will largely depend on your system and the efficiency you are currently getting as a result of the pre-crushed grains. If you are currently getting poor efficiency then it may improve it but it could also have the opposite effect if your efficiency is currently high.

What it will almost certainly do is help deliver a more consistent efficiency as you can directly control the grain crush size for each brew rather than being at the mercy of whoever is doing it for you. However, efficiency is affected by a whole host of other things (mash temperature, mash thickness, mash pH, etc.) so unless you've got those controlled consistently then you'll probably not notice a significant difference.

 

[Bzee]

I always crush my own malt but recently got sent a sack of crushed by mistake and rather than send it back in decided to use it. It was very fine compared to what comes out of my mill (still on factory settings) and I noticed 2 things. Dough balls everywhere and much better efficiency. It was Pops pale ale malt. I then went back to milling my own slightly finer than before.

 

[dcbrookes]

I always crush my own malt but recently got sent a sack of crushed by mistake and rather than send it back in decided to use it. It was very fine compared to what comes out of my mill (still on factory settings) and I noticed 2 things. Dough balls everywhere and much better efficiency. It was Pops pale ale malt. I then went back to milling my own slightly finer than before.

I am having the opposite experience. Using my GF mill with the G40 I normally get 82% efficiency, I recently (accidentally) bought a sack of Paul's factory crushed lager malt and my efficiency with this is only 76%.

 

[Cwrw666]

I think higher efficiency or otherwise is due primarily to the fineness of the grind. My grinder produces a lot of fine flour and my efficiency is around 83% last time I checked. But I do biab so a stuck mash is not a problem for me but even so I sometimes have a bit of difficulty getting the bag to drain. With other systems it might be a real problem.

 

[dmtaylor]

Millions of homebrewers including myself discovered their efficiency increased by about 10% overnight by getting their own mill.

Do it.

 

[Stu's Brews]

To play devil's advocate a little bit...

How many brews would you have to do before you've saved enough from reducing the amount of grain you need to use to cover the costs of a grain mill?

Using this grain mill from Malt Miller which costs £98 as an example I reckon it would take something like 98 brew-days to recoup your investment (if you saw a 5% increase in efficiency you could use ~300g less grain for an ~5.5% brew which is roughly £1 per brew).

 

[Agentgonzo]

you could use ~300g less grain for an ~5.5% brew which is roughly £1 per brew

You buy expensive malt! I get a 25kg sack for roughly £30

 

[Stu's Brews]

You buy expensive malt! I get a 25kg sack for roughly £30

I was just working off the prices quoted per 1kg on the Malt Miller website as it is what I had opened at the time.

Ironically though, if you buy your malt in bulk then it actually decreases the argument for investing in a grain mill as it will take even longer to pay off (250-300 brews!). Of course, that assumes improving efficiency is the main reason for buying a grain mill.

 

[Birdsnestbrewery]

Yeah, consistency is the main concern I think, rather than getting the highest numbers.

 

[Cwrw666]

Using this grain mill from Malt Miller which costs £98 as an example I reckon it would take something like 98 brew-days to recoup your investment

Well mine cost 30 quid. I reckon I get an extra brew out of a sack of 25Kg.

 

[Covrich]

Brewing process can be a big reason to mill your own. if you BIAB then a fine grist can boost the numbers , but being consistent is where you want to get too.

 

[JockyBrewer]

One thing is that if you're buying a sack of 25kg pre-milled then inevitably the grain settles. You get coarser grain and husk at the top and more flour at the bottom, and that will cause your efficiency to be inconsistent on its own.

I also believe in milling the grain as late as possible helps with freshness (although it's very marginal). German breweries use very expensive 'hydromills' to crush the grain under deoxygenated water to help avoid the grain picking up oxygen between crushing and mashing.

 

[Big_Eight]

Brewing process can be a big reason to mill your own. if you BIAB then a fine grist can boost the numbers , but being consistent is where you want to get too.

It's also nice to be able to adjust for different grains like wheat which generally requires a smaller gap. Sometimes kits that come crushed don't have grains such as wheat milled that well or at all (not all the time but it happens).

It's also another control the brewer can have over the process and not be at the mercy of a shops crush consistency.

 

[dcbrookes]

I was just working off the prices quoted per 1kg on the Malt Miller website as it is what I had opened at the time.

Ironically though, if you buy your malt in bulk then it actually decreases the argument for investing in a grain mill as it will take even longer to pay off (250-300 brews!). Of course, that assumes improving efficiency is the main reason for buying a grain mill.

It's not just about efficiency though, is it? I have a G40 which cost me almost £1100 - I could do decoction mashes with a saucepan, a plastic bucket and a blanket, which would have saved me a shedful of money ... and driven me insane. Spending money on kit we can afford is part of the pleasure of our hobby, and for me the GF grain mill does not have to save me a penny to justify its purchase.