Efficency??????

[danskitt]

I have done two AG brews now, the first was really poking around in the dark but the second one went quite smoothly. I keep hearing about efficency though and I have no idea what it means or how it is worked out. I have read up on it but I think with all the brew terminology that is used I am missing the point. Can anyone explain it in really terms with out using the lingo or point me in a direction that will?

[Fuse]

Efficency is the difference between what is the possible technial maximum amount of sugars in the grain vs what you actually manage to achieve.

You won't be able to remove all of the sugars to achieve 100% as in doing so you would have undesirable side effects, like tannin extractions etc. The higher the OG the lower you efficency will also be.

In plain terms for a 4% beer you should be able to get 70% or more, For example, if you have 4kg of grain in a 23L brew. With 100% efficency you would expect to get 1.052 for your OG, in reality you are more likely to get 80% which would be 1.042.

[fatbelly]

So how do you gauge what your Efficency is? What are the mechanics of the process.

Thanks FB

[danskitt]

So how do you go about calculating the efficency, what is the formula?

[far9410]

It all depends on your kit and procedure . You can only know this when you compare to a fixed recipe

[gregorach]

The calculation's got nothing to do with kit or procedure, and it's easy enough to work out for any recipe.

Firstly, there's a couple of different ways of doing this - you can calculate a "total brewhouse" efficiency (which takes all loses into account) or just a "mashing / lautering" (or "MLT") efficiency, which just looks at the efficiency of extraction and ignores boiler losses. I find the latter more useful and rarely bother to calculate the former.

First, you calculate the maximum possible extraction, based on the LDK (Litre-Degrees per Kilo)) number for your malt. For example, a typical LDK for pale malt is 300 - which means that if you dissolved all of the possible sugars from one kilo in one litre of water, the OG would be 1.300. So, get the LDK number for each malt in your recipe and multiply by the amount used (in kilos) and add them all up - this gives you the maximum extract potential for that recipe. Now, take a gravity reading of your wort and multiply by your volume (final wort volume to calculate total brewhouse efficiency, pre-boil volume to calculate MLT efficiency) - this gives you your actual extract. Divide actual extract by potential extract and multiply by 100, and that's your efficiency.

For example, suppose you mash 5kg of pale malt (300 LDK) and end up with 30L @ 1.042, pre-boil. Your potential extract is 5 x 300 = 1500, your actual extract is 30 x 42 = 1260, so your MLT efficiency is (1260 / 1500) x 100 = 84%. Now further suppose that after the boil and run-off, you actually end up with 22L @ 1.050 in your FV (here I'm assuming that you've lost about 5L to evaporation and 3L to hops and trub) - this gives you a final actual extract of 22 x 50 = 1100, and your total brewhouse efficiency is (1100 / 1500) x 100 = 73%.

You can find typical LDK values for a range of malts on several maltsters' websites.

[Lime Corridor]

The calculation's got nothing to do with kit or procedure, and it's easy enough to work out for any recipe.

Boom! gregorach blows it out of the water!

+1 for the spot on and detailed response.

LC

[Scooby]

It's all here on Jim's. Hint's and tips-recipe formulation

[danskitt]

Thanks Dunc, good easy reply. I have worked out my last efficency which works out at 84% which seems a little to good for only my second attempt, what do you think?

[FatGaz]

Efficiency - its one of those things that I sort of understand, yet dont understand at the same time! All I know is that my first few GW brews came out with a higher ABV than expected - so I must be getting a higher efficiency than the recipe.

[PureGuiness]

Efficiency - its one of those things that I sort of understand, yet dont understand at the same time! All I know is that my first few GW brews came out with a higher ABV than expected - so I must be getting a higher efficiency than the recipe.

As long as you hit the brew length spot on and fermented out to the expected FG then this is true.

[Scooby]

Efficiency - its one of those things that I sort of understand, yet dont understand at the same time! All I know is that my first few GW brews came out with a higher ABV than expected - so I must be getting a higher efficiency than the recipe.

Yep I agree with that, you sort of understand yet don't

ABV has nothing to do with efficiency.

[dinger44]

ive been using this calculator for the last few brews.

http://www.brewblogger.net/index.php?pa ... efficiency

tho im lost when it comes to this stuff lol.

[gregorach]

Thanks Dunc, good easy reply. I have worked out my last efficency which works out at 84% which seems a little to good for only my second attempt, what do you think?

That's a good efficiency, but certainly not outwith the bounds of possibility. Well done.

[filet o fish]

why is brew house not useful ?

presumably you are going to boil in a similar way each time?

just interested. am always amazed at the amount of water i lose in the grain, evaporation , in the hops etc . I mash and see the hydrometer and think, wow this time i am going to get loads of beer out.....doesnt quite happen though.