How much does your efficiency vary?

[Andrew R]

What I'd like to know is, over the course of many brewdays, how much do people's mash efficiencies vary? I don't so much care about the number you get - but just how much it varies from one batch to another. Are you always getting the same efficiency? Or do you get somewhere around a percent or two or more out? 

I ask because I've been doing BIAB for close to a year now. But that's not as much an achievement as I'd like it to be as work has been seriously busy and got in the way of brewing. So I've only managed to find the time for 6 or so brews. But my efficiencies are wild. Now I suspect my technique with BIAB - because I think that I'm not all that disciplined. From brewday to brewday I treat the bag juat subtly  differently each time ( I'm sure I must squeeze harder one day than the next - hold it over the pot a fraction longer the time after to drain it more). And as such, I'm converting an old chilly bin into a mashtun and I'm going to start batch sparging with a view to eliminating the number of variables I encounter with my current process. But I am wondering if I'll be able to expect a much more predictable brewday - or do I just tinker too damn much?

[denimglen]

I actually downloaded the set of info you put up a while ago for importing into beersmith. But how often would you say that info would need to be updated? I'd imagine at least once every growing season is a bare minimum...?

Yeah, I'd say there would be differences between each harvest and also each malting batch.

But I wouldn't expect to see any major differences between harvests and maltings of the same malt type. As long as you're using the correct analysis for the malt type and maltster you should be pretty close. The important thing is not to just use a generic base malt profile if you want to get a good hold on your efficiency.

I've been changing base malts about every six months or so and getting a new analysis sheet with each change and it seems to be pretty consistent so far.

Ah, technically you can't 'screw up' beer, like someone said once - barley wants to become beer, the brewer is there just to push it along :-)

[Andrew R]

Yep, I gotta say that even though I get some weird amount of variation with the numbers and the technique needs refinement, the beer I produce still tastes quite good. I'm certainly not discouraged!

[warra48]

I normally get mash efficiency into the 90+%.
Here are my current drinking beers from BeerSmith, with mash efficiency and kg of grain used.
All batches are 23 litres.

Bitter 100.36% 3.80 kg
APA 96.68% 5.05 kg
BoPils 96.28% 5.00 kg
Bitter 92.47% 4.26 kg
Old 89.72% 5.45 kg
Weizen 92.52% 5.00 kg
Dunkel 68.83% 4.72 kg
APA 98.09% 4.86kg
Mild 95.48% 3.60kg

The dunkelweizen is because of a disaster on brew day. Guess who left the HLT tap running into the mashtun, and didn't realise it until he had a serious flow over?
I also used to get about 10% less efficiency with Maris Otter, until I found that mashing for 90 and up to 120 minutes brought the efficiency back up.
I really have little variation from brew to brew if all goes well.
My process tends to be the same from brew to brew, and I think that is the key to repeatability. If you do the same thing each time, you should get close to the same result.
I haven't adjusted my mill for about 18 months, and just leave it alone, set at about 1.1 mm, not really all that fine.
My boil off rate is stable, as I brew in my garage. However, if the humidity is up, then the boil off rate does tend to drop from when it is dry, but I can allow for that in what I collect into the kettle pre-boil.

[Reviled]

100% on that bitter Warra??? Is that mash efficiency? Wowza, thats good, and was that with Golden Promise?

Ive also noticed a drop in eff using Maris Otter lately, about 5% over what I normally get, I might try the 90 min mash thing and see if that helps... Now im a bit worried that the maris wouldnt have converted all of my maize in my cream ale yesterday, but it doesnt seem starchy so im sure it will be fine...

[warra48]

That's correct on the bitter at 100% mash efficiency. I used Maris Otter doing a 2 hour mash and a 90 minute boil.
I once got 103% on a hefeweizen, but it wasn't one of my best brews.

My usual local supplier (MHB) believes Maris Otter needs a 2 hour mash and a 2 hour boil. It is the last of the old fashioned malts still available to us, and needs this sort of regime similar to what the UK brewers did years ago.

These are his thoughts on Maris Otter:

The problems being
Turbidity (cloudy as all get out)
Low foam
Poor bottle life (stability)

Maris Otter is an old fashion malt; it’s the last of its generation still in use, after having a long hard look at the brewing processes in use when MO was a “Typical” brewing malt, the things that really stood out was that all the brewing was done to the old 400 minute standard brew day, (yep over 6 ½ hours from grain to knockout) and that hop alphas were rarely over 5% with 3-4% being typical.
Now you would think that long mashes and boils would remove way too much of the head building protein (low to start with) but when you try the long process you will get crystal clear beer that’s stable in the bottle and holds a head you can’t kill with a big stick. It’s the hops that build the head in these “Old Fashioned Beers” more than the protein.

If you want to try, do a 100% MO (you will get plenty of colour from the long boil), if you must use some crystal malt go easy (say 5%) and use low alpha hops, first choice would have to be EKG, just one addition at the end of the hot break foamy stage, aim for about 35-40 IBU. Mash lowish (64-65) and you don’t need a raging boil; you still want 8-10%/hour and don’t be afraid to top up to hit your volume.
And a big one – don’t get any of the trub into the fermenter, its head fatal.