Grain Efficiency

Stu · Monday at 12:56 PM

I made a stout last weekend which I didn't read the instructions properly, so I effectively ended up with a brew that's around half what was expected.

However, a couple of things.

Firstly, efficiency. Speaking to a professional brewer, he was explaining that stouts are generally fairly low on efficiency. The particular recipe I used, he said to expect around 60%. I only got 55%.

In terms of amounts, here's what I did.

Started with around 22 litres of strike water. Warmed it to 68c and mashed for 90 minutes. Plenty of stirring with a paddle and recirculating.
Then took 7 litres of sparge water, heated it and rinsed the grains. Left for about 15 minutes, then a half-decent squeeze to dry and get some of the liquid out.

Ended with around 26 litres going into the 90 minute boil. Ended with around 23 litres.

I think I'm doing something wrong to try getting efficiency better. I don't want to do a super long mash - I really don't want it getting bitter.

Appleton Brews · Monday at 1:15 PM

Can you post your recipe please. I made a stout recently and although the brew house efficiency was a bit low at 73% rather than my average of 75% the yeast attenuation was 67% rather than 79% giving me ABV 3.9% rather than 4.5%. I have also had stouts with low efficiency. The problem is the dark malts which have no fermentable sugars. In future I’m going to add the dark malts at mash out and add more pale malt to get the required OG.

Stu · Monday at 1:22 PM

Appleton Brews said:
Can you post your recipe please. I made a stout recently and although the brew house efficiency was a bit low at 73% rather than my average of 75% the yeast attenuation was 67% rather than 79% giving me ABV 3.9% rather than 4.5%. I have also had stouts with low efficiency. The problem is the dark malts which have no fermentable sugars. In future I’m going to add the dark malts at mash out and add more pale malt to get the required OG.

https://www.brewersfriend.com/homebrew/recipe/view/1523053/something-something-stout

Larse · Monday at 1:55 PM

Since I started adding rice hulls (5%) to my mash, the efficiency has shot up. Made a stout - there's a thread about how it finished a bit high - not unlike what @Appleton Brews encountered, but I calculated the efficiency at 90% working backwards from the OG. I had to liquor back to match the target OG, so my fermenter volume was 27L, should have been 23L.

Appleton Brews · Monday at 2:40 PM

Stu said:
https://www.brewersfriend.com/homebrew/recipe/view/1523053/something-something-stout

Wow just adding the black, chocolate and roasted barley that’s 21% which is huge, I’m not surprised the efficiency is low.

Clint · Monday at 2:45 PM

My efficiency was quite low on all accounts until I changed the bazooka filter in the mash tun for a copper manifold type. I also kept my sparge water temp constant and slowed the sparge down and put a perforated tin foil sheet on top of the mash.

The Baron · Monday at 2:49 PM

There is enough Diastatic power it shows approx 40 with a minimum of 30 required but from a personal point of view it is way too much dark malts the Black patent at that level may be well acrid and bitter, if using black patent for colouring I only add it for the last 10 minutes of a mash for that reason and 500g is well more than I have ever used.
I would certainly tone them down and as suggested add some of them late in the mash so as not to be as overpowering

Manxnorton · Monday at 3:06 PM

Clint said:
My efficiency was quite low on all accounts until I changed the bazooka filter in the mash tun for a copper manifold type. I also kept my sparge water temp constant and slowed the sparge down and put a perforated tin foil sheet on top of the mash.

hallow m8,
hope thing good at your end pal.
Yeah i faffed on with the sparge water an my reading went higher.
take care.
Bri

Stu · Monday at 5:02 PM

Thanks all. I'm going to have another go at it this weekend (using the original recipe).
Point taken about the black. I'll dial it back a bit.

I've thought about rice hulls before. Every time I've gone to use them, TMM are sold out.

foxy · Monday at 9:12 PM

Stu said:
I made a stout last weekend which I didn't read the instructions properly, so I effectively ended up with a brew that's around half what was expected.

However, a couple of things.

Firstly, efficiency. Speaking to a professional brewer, he was explaining that stouts are generally fairly low on efficiency. The particular recipe I used, he said to expect around 60%. I only got 55%.

In terms of amounts, here's what I did.

Started with around 22 litres of strike water. Warmed it to 68c and mashed for 90 minutes. Plenty of stirring with a paddle and recirculating.
Then took 7 litres of sparge water, heated it and rinsed the grains. Left for about 15 minutes, then a half-decent squeeze to dry and get some of the liquid out.

Ended with around 26 litres going into the 90 minute boil. Ended with around 23 litres.

I think I'm doing something wrong to try getting efficiency better. I don't want to do a super long mash - I really don't want it getting bitter.

There are a few things wrong besides the amount of speciality malts. 100g of hops and 216 IBU? Target water profile, there isn't one which suggests you haven't added your own water profile. If you haven't got a water profile you cant adjust your water.
Mash pH is important for the conversion of starch, the base malt on its own will take you close to a mash pH and putting all the dark grain in would have made for a very acidic mash.

For a dry Irish stout, I put 85% base malt, 10% flaked barley, (this will give body and add dextrin's for head, and add fermentable sugar) 5% of roast malt at mash out. Depending on your water profile you wouldn't have to add much in the way of salts. One charge of hops at 60 minutes, which you did. No good faffing around with any other hop additions for a dry stout.

Larse · Tuesday at 7:00 AM

Stu said:
Thanks all. I'm going to have another go at it this weekend (using the original recipe).
Point taken about the black. I'll dial it back a bit.

I've thought about rice hulls before. Every time I've gone to use them, TMM are sold out.

GEB always have them.

Sadfield · Tuesday at 8:29 AM

DO NOT FEAR THE ROASTED MALT.

This is the recipe for Truman's Stout from 1890 with 9% Black Malt on top of 14% Brown Malt.

https://barclayperkins.blogspot.com/2010/01/lets-brew-wednesday-1890-truman-export.html?m=1

The recipe is the basis of this beer, which is delicious and far from being acrid.

JockyBrewer · Tuesday at 8:53 AM

In an American style stout 20% mix of roast barley, chocolate malt and dark crystal works really well along with a high hop rate.

Here's a recipe that has won a couple of medals, including 3rd best of show at Black Friday 2021: https://londonamateurbrewers.co.uk/wiki/index.php/Hard_Top

Mash efficiency 74%
Brew house efficiency 65%

Sadfield · Tuesday at 8:59 AM

Even Guinness is 10% Roasted Malt and it's bland.

@JockyBrewer the link returns to this thread not the recipe.

JockyBrewer · Tuesday at 9:09 AM

Stu said:
Firstly, efficiency. Speaking to a professional brewer, he was explaining that stouts are generally fairly low on efficiency. The particular recipe I used, he said to expect around 60%. I only got 55%.

First of all I'd say not to fuss too much about efficiency. I had terrible efficiency for the longest time. If it's a problem just adjust your base malt up to compensate.

Two things fixed it - first of all was sparging more and slower. I went back to 2.5 litres/kg grain of strike water so there was more sparge water and then I sparged slower. Typically these days I mash for an hour and sparge for an hour, but a couple of weeks ago I did a quick beer where I mashed for half an hour and then did a single batch sparge. My mash efficiency dropped from around 75% to 65%, but with a 30 minute boil I was all done in 3 hours and had a lovely day.

Second thing was water chemistry. If you're seeing big changes for a stout then it's possible the mash pH isn't right. Have you looked at adjusting your mash water alkalinity?

Stu said:
In terms of amounts, here's what I did.

Started with around 22 litres of strike water. Warmed it to 68c and mashed for 90 minutes. Plenty of stirring with a paddle and recirculating.
Then took 7 litres of sparge water, heated it and rinsed the grains. Left for about 15 minutes, then a half-decent squeeze to dry and get some of the liquid out.

Ended with around 26 litres going into the 90 minute boil. Ended with around 23 litres.

I think I'm doing something wrong to try getting efficiency better. I don't want to do a super long mash - I really don't want it getting bitter.

A longer mash won't make it bitter.

Over sparging can make a beer astringent, but for that you need to be fly/continuous sparging and for the runnings to go below 1.010. Not going to happen when you batch sparge.

JockyBrewer · Tuesday at 9:10 AM

Sadfield said:
@JockyBrewer the link returns to this thread not the recipe.

I'm a dummy, link fixed. Thanks for the catch @Sadfield.

Clint · Tuesday at 9:14 AM

Yep agree! My sparge lasts about a hour. You just have to weigh it all up...either it's your time or your money. You can even add some sugar of some sort to hit your numbers without affecting the beer very much.

borischarlton · Tuesday at 10:01 AM

Stu said:
Thanks all. I'm going to have another go at it this weekend (using the original recipe).
Point taken about the black. I'll dial it back a bit.

I've thought about rice hulls before. Every time I've gone to use them, TMM are sold out.

I can't remember the last time they were out of stock, we sell a huge amount of them.
This is the link https://www.themaltmiller.co.uk/product/rice-hulls/

JockyBrewer · Tuesday at 11:15 AM

borischarlton said:
I can't remember the last time they were out of stock, we sell a huge amount of them.
This is the link https://www.themaltmiller.co.uk/product/rice-hulls/

Is there any practical difference between rice hulls and oat husks?

I also noticed a while ago that the prices of them spiked hugely - when I made an order in August oat husks were £8.80/kg, whereas now they're £2.50/kg?

borischarlton · Tuesday at 11:43 AM

Yep, we had an IT issue!! Oat husks, the price changed for a very short period, we soon sorted it after being shouted at quite loudly! Basically there was a tick in the wrong box

Grain Efficiency

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