# Calculating Extract Efficiency



## merrick (1/12/07)

Help! Can someone please explain to me in words of one syllable how to calculate brew extract efficiency. If it involves taking a specific gravity reading do I let the wort cool down first? Is it intended to refer only to mashed grain, or are calculations performed after addition of things like crystal malts etc? At the moment it all seems like a glorious mystery to me. Thanks in advance.

Merrick


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## pb unleaded (1/12/07)

Hi.
I have this formula from G&G website, you need to know your OG, grain weight in kg and batch size in lt.

Efficiency(%) = OG X batch size X 100 / 307 / grain weight

To work out your potential OG use this formula:

OG = grain weight X (280/batch size)



arthur


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## Sammus (1/12/07)

I just use beersmith. Dunno how accurate that forumla above would be, because AFAIK, different kinds of grain had different extract potentials.


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## merrick (1/12/07)

arthur said:


> Hi.
> I have this formula from G&G website, you need to know your OG, grain weight in kg and batch size in lt.
> 
> Efficiency(%) = OG X batch size X 100 / 307 / grain weight
> ...



Thanks Arthur,

I've looked at the G&G article, and while it refers to the Original Gravity (OG), it doesn't say when to take that Hydrometer reading. If a reading is taken immediately after mashing etc, but before boiling the wort, it would surely produce a totally different reading than if it was allowed to cool to say 21C. If the reading is taken after the wort has been boiled and allowed to cool, by that time the wort would contain other items such as adjuncts and would distort the original malt measurement. Or have I still got it all wrong and the penny needs to drop?

Merrick


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## pb unleaded (1/12/07)

merrick said:


> I've looked at the G&G article, and while it refers to the Original Gravity (OG), it doesn't say when to take that Hydrometer reading. If a reading is taken immediately after mashing etc, but before boiling the wort, it would surely produce a totally different reading than if it was allowed to cool to say 21C. If the reading is taken after the wort has been boiled and allowed to cool, by that time the wort would contain other items such as adjuncts and would distort the original malt measurement. Or have I still got it all wrong and the penny needs to drop?



The gravity at the end of mashing and begining of boil should be the same. It will be higher as boil progresses as some water will evaporate. 
Cool the sample to 20 deg C if using a hydrometer. 
To work out efficiency, measure at end of mash. Measure again at the end of boil for fermentation purposes.


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## warra48 (1/12/07)

Here is link which gives a table for correction of hydrometer readings taken at various temperatures.
http://www.howtobrew.com/appendices/appendixA.html


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## merrick (1/12/07)

Thank you all. I think I've got the hang of it now.

Merrick


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## Zwickel (1/12/07)

hi brewmates,

just to make the confusion perfect  

How do I calculate the brewhouse-efficiency?

well, Ill try to explain, despite of my poor english, for that I must apologize.

first I have to explain that were calculating the extract in %, not like most of Australian homebrewers do in gravity.
the percentage is approxymately 1/4 of your readings behind the 1000
for example, your reading is 1048, that means 12% extract.

first we measure the Wort in litre, but we need it in kg.
approxymately we may calculate the density of wort as follows:

0 Mass % --> density = 1
1 Mass % --> density = 1.004
2 Mass % --> density = 1.008

we may calculate:

(1) Mass [kg] = Volume[l] * (1 + Mass% * 0,004) [kg/l]

but stop, this only if the wort is at 20C
if the wort is still boiling or very hot, we have to calculate a contraction-factor of 0,96
that means: (2) Volume [l, 20] = Volume [l, 100] * 0,96

Now we may reckon the weight of the wort:
(1)+(2)
(3) Mass [kg, 20] = amount of wort[l, 100] * 0,96 * (1 + Mass% * 0,004)

In this amount of wort is contained:
(4) Extrakt [kg] = Mass [kg, 20] * Extrakt-readings[%] / 100

or easier:
(5) Extrakt [kg] = amount of wort[l, 20] * 0,96 * (1 + Mass% * 0,004) * Extrakt-readings[%] / 100

now we can conclude:
(6) brewhouse-efficiency = Extrakt [kg] / amount of grain [kg] * 100 %

pooooohhh, hard work for me writing in english....

have fun :lol:


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## Sammus (1/12/07)

Surely the extract efficiency has to depend on what kind of grains your using? Could someone explain to me why this doesn't seem to be the case. I find it hard to believe that every gain a brewer might use has the same amount of sugar potentially extracted from it...


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## Zwickel (1/12/07)

Sammus said:


> Surely the extract efficiency has to depend on what kind of grains your using? Could someone explain to me why this doesn't seem to be the case. I find it hard to believe that every gain a brewer might use has the same amount of sugar potentially extracted from it...


Sammus,

the only thing you have to count is the amount of sugar you get out in relation to the weight of the grain, nothing else.
So it doesnt matter what grain you are using.

For example, if you get 800g of sugar out of 1kg of any grain, that would be 80% efficiency.

just another example how to count efficiency:

youve done a batch size of 24l of wort at 1048
you have used 4kg of grain

we may count now: 1048=~12% extract (sugar)
12% extract=~120g sugar per kilo
24L of wort at 1048= 24*1.048= 25,152kg
lets say, 24l of wort are weighting 25150g
12% of 25150g= 3018g of sugar
3018g of sugar out of 4000g of grain= *75,45% efficiency*

thats quite simple, isnt it?

Cheers :icon_cheers:


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## pb unleaded (1/12/07)

Sammus said:


> Surely the extract efficiency has to depend on what kind of grains your using? Could someone explain to me why this doesn't seem to be the case. I find it hard to believe that every gain a brewer might use has the same amount of sugar potentially extracted from it...



These formulas are good for *Australian well modified malted barley*. If using other malts refer to malsters specs for that particular type, I guess,
...or just use a programme. Much easier.

Here is an 'extract'  I copied from Grain and Grape website:

The formula below is based on the laboratory extract figure for Australian well modified malted barley. This figure is expressed as "Brewers Degrees per Kilogram Litre" (BD/KL). This means the maximum possible extract attainable from a kilogram of malt mashed to produce a litre of wort. "Brewers Degrees" (BD) are a simplified version of an "Specific Gravity" (SG) reading and are expressed as follows:

SG 1.050 = 50 Brewers Degrees
SG 1.012 = 12 Brewers Degrees

The BD/KL for Australian well modified malt is for"ale" 307, and for lager 302. This means that by following a strict procedure as laid down by the European Brewing Convention (EBC), one kilogram of malt mashed to produce one litre of wort would have an SG of 1307, or 307 BD/KL.

cheers

arthur


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## Sammus (2/12/07)

Zwickel said:


> Sammus,
> 
> the only thing you have to count is the amount of sugar you get out in relation to the weight of the grain, nothing else.
> So it doesnt matter what grain you are using.
> ...




But grains have husks and insoluble starches - things that cannot be dissolved in the mash. And the percentage of the grain which is insoluble varies from grain to grain. What your calculating is the yield by weight of *soluble* materials. The word _efficiency_ implies that it is (even theoretically) possible to attain 100%. Using your efficiency calculations I guarantee that you will never hit 100%  (ie get 1kg of sugar extracted from every kg of malt)*

And Arthur: That quote from G&G illustrated my point exactly, its showing you that two different types of grain have different amounts of soluble material within them. Specialties tend to vary a bit (not just any malt from other country), and in particular, something like black malt or roast barley would be a lot less than that.

My point being is that I think this needs to be taken into account if you want a true efficiency rating.

*edit: the last part of that paragraph, along with this footnote that proper efficiency calculations are for some silly reason actually compared to a lab mash - a technique which isnt completely efficient itself, this making it possible to attain efficiencies > 100% - where by efficiency I mean the kind of efficiency that all the brewing textbooks and brewing software uses.

edit2: read this if you what to know where I'm coming from. He (Palmer) first just compares to the extract potential of lager malt, but calls it an approximation - if you much much specialty malt in your mash it's going to throw this way out


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## MHB (2/12/07)

The extract potential is determined by a laboratory test; for base malt; from memory it goes something like this:-

Grind 100g of grain to powder
Mix with 1 Litre of water hot enough to give a 65C mash
Hold at 65C for 1 hour (this is done in a water bath)
Filter through laboratory filter paper (usually vacuum filtered in a Buckner Funnel and Erlenmeyer Flask with side arm)
Cool to 20C
Measure extract

This is the extract potential for that grain.

Link to Malt Specification

For this malt the *Extract Fine Crush* potential is 81.7%, that is to say 81.7% of the malt goes into solution.
If you got the same yield you would be getting 100% efficiency. But the comparison is being made to a standard test, so 75% is 75% of what the test gave for that malt. Not 75% of the mass of grain used.

As an isothermal mash at 65C isnt the most efficient way to make extract; it is possible to get more than 100% efficiency, modern breweries using mash filters and tightly controlled step mashes regularly report 110% yields.

Obviously the test above gives very low values for malts that have no enzyme power (i.e. roast Barley) there is I understand a modified test for malts and grains other than base malts.

Hope thats not as clear as mud
MHB


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## Tony M (2/12/07)

Our good member Jayse posted this a couple of years ago and it seems a quick and easy method.


Mash Efficiency

anyway brew maths is quite simple.

How it works is all malts and adjuncts etc give a different gravity. 
The specs are all written as H.W.E which is hot water extract with sugar being the highest at 386 so everything else is given as a % of that. ie, pale malt is around 81% which gives you around 309. this is the total gravity you can get with 1 kilo in 1 litre but it is impossible to get this, this is 100% effeincy.
the same goes for american calcs but its in P.P.G which is the gravity of 1 pound in 1 gallon. The same specs are used ie. 81% for pale malt gives you 37 points of gravity.

So a simple example to work out total potential for 5 kg of pale malt in 23 litres is
5 x 309 / 23 = 67 (1.067)

now to work out your effiency you divid the gravity you got with this brew. Say you got 1.050 so 50/67 =.74 you got 74% effiency.
Then next time when you do the calc. 5 x 309 /23 =you simply times this by .74 .
This gives you your expected gravity, 

For you first batchs i would stick to using 60-65%.
So do the 5 x 309/ 23 = 67.
then times 67 by .65 = 43(1.043)


am i making any sense here
Jayse

p.s the hwe numbers are all on the malt craft site other malts like crystal malt are around 75% some malts can be lower and some higher.
to get the number times 386 by the percent as a decimal point ie pale malt at 81% gives you 386 x .81 =312 

Ale -------81% X 386 = 312
Pilsner----------------81%
Hoepfner Munich----80% 308
Melanoiden--------- -80%
Caramalt pils---------79% 305
Crystal---------------- 75%


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## Zwickel (2/12/07)

Sammus said:


> But grains have husks and insoluble starches - things that cannot be dissolved in the mash. And the percentage of the grain which is insoluble varies from grain to grain. What your calculating is the yield by weight of *soluble* materials. The word _efficiency_ implies that it is (even theoretically) possible to attain 100%. Using your efficiency calculations I guarantee that you will never hit 100%  (ie get 1kg of sugar extracted from every kg of malt)*


Sammus, thats absolutely right, you never can reach 100%.

Average efficiency of German breweries lies around 75-78%.

The only thing I can say is, if youre going to count efficiency in a different way, then your results are not comparable to what we understand that efficiency is.

Cheers


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## deckedoutdaz (2/12/07)

As per usual, i was lost when i was told to listen carefully!....

Daz


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## shawnheiderich (2/12/07)

Thanks now I can work out my efficiency for my first few AG brews. First one turned out to be about 55% need some work on that ... But at least now I am not working in the dark.


Shawn


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## dig (3/12/07)

My two cents worth:

Like MHB said, decide whether it's extract efficiency that you're after (how many grams of extract you're getting for each kilo of malt) or brewhouse efficiency (how close are you getting to replicating a congress mash). For this, you'll need to know your malt specs.

Either way, get yourself one of those little $15 Brew Computer slide rule thingies from the Seibel Institute in the US. Among its many tricks, it'll convert your OE to 'kilos of extract per hectolitre'. Multiply this figure by your volume to give you total extract in kilos. Dead easy.

And lastly, just to throw a spanner in there, things like efficiency will always be calculated and quoted either as 'dry basis' or 'as is'. If your malt has a moisture content of 4%, one kilo is not one kilo, it's 960 grams of malt and 40 grams of water. If you get 800g of extract from one kilo of malt that has a moisture content of 5%, efficiency is not 80%, it's 84.2% because you only realy started with 950g of malt on a dry basis. Fry your noodle.


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## Stuster (3/12/07)

Or how about just getting the trial version of Promash and Beersmith and let the machine do the work.


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## Whistlingjack (3/12/07)

dig said:


> And lastly, just to throw a spanner in there, things like efficiency will always be calculated and quoted either as 'dry basis' or 'as is'. If your malt has a moisture content of 4%, one kilo is not one kilo, it's 960 grams of malt and 40 grams of water. If you get 800g of extract from one kilo of malt that has a moisture content of 5%, efficiency is not 80%, it's 84.2% because you only realy started with 950g of malt on a dry basis. Fry your noodle.



Well spotted, that man.

You have to agree, though, that its unlikely that you will get that much of a variation in moisture content when you buy malt. Maybe the storage conditions (under water) will contribute to an increase in moisture but this is speculative only.

4% moisture content is the standard and the malt will not absorb any more water unless some one adds it.

WJ


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## Zwickel (3/12/07)

Stuster said:


> Or how about just getting the trial version of Promash and Beersmith and let the machine do the work.


howdy folks,

I see there are many ways to calculate efficiency. Basically it wouldnt matter how to calculate it, as far as you (or everyone) always do it the same way.
To be comparable with other brewers or breweries, we should use the same calculation, otherwise were talking a different language about different things.

Ive read in an American forum that teire way to calculate efficiency is, to determine the content of starch first and then say thats 100%. So depends on your ability to get out a certain amount of starch to be converted into sugar, you possibly can reach the 100%.
But thatfore youll need a labor analysis for each kind of grain. Thats not practical for us.

I got learned the way I discribed in my posts and all the german brewers do so. We say, just calculate the amount of sugar you get in relation to the weigt of material you have used. This way it doesnt matter what kind of material is used and no matter its wet or humid, that even can be potatoes.

So I dont want to push the way were calculating efficiency, Id just like to be comparable to others.

I often was wondering how you guys can get an efficiency far more than 80%, Ive never reached, now I know, its the way you calculate it.

Once again, I dont insist in using the formula Ive posted, but if were talking about efficiency, were talking about different things, were not comparable.
But this seems to be my own problem, Im the alien here :lol: 

Cheers mates :icon_cheers: 


btw. for those who are interested, here is a website you can see the same formula Ive posted. Go to the section/column "Sudhausausbeute". Sorry its only in German language, but you may be able to understand, its only a few words, just type in your datas:
http://fabier.de/biercalcs.html


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## Stuster (3/12/07)

Ah, your numbers weren't big enough hey, Zwickel. :lol: 

As you say, just different ways to do the same thing. Your way does lead to lower efficiency numbers, but the main thing is to know the standard number for your system so you can base your future recipes on that level of efficiency. There's no need for an analysis of the grains when using software instead of brains as the standard figures for those grains are in the program data or can be downloaded. There may some variation, but it's probably minor compared to the variation between batches in the standard homebrew setup (not necessarily your one though).


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## Hopfenkopf (3/12/07)

Doesn't matter whether you use gravity or density as your measure, as long as you calculate the result in the same way each time.


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## Zwickel (3/12/07)

Stuster said:


> Ah, your numbers weren't big enough hey, Zwickel. :lol:


yeah, I was always ashamed when Ive read your big numbers in efficiency, didnt want to post the number of my poor yield  

I always have been thinking: must improve my brewing methode, must improve my brewing methode, must improve my brewing methode.....

Now Im relaxed, just have to take a course in brewing mathematics :lol: 

Cheers mates :beer:


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## MHB (3/12/07)

Ultimately the method you use isnt that important, so long as you are consistent.
Extract efficiency is not the be all and end all - that place is reserved for "Brewhouse Efficiency" - but is rather one of the pieces of information you need to refine your recipes and processes.

I for one have always been bemused by AHB'ers proclivity for posting efficiency numbers, without qualifying what they mean; like Zwickel said most breweries report 75-78% efficiency; that is brewhouse efficiency - how much goes into the fermenter / what could go in - in a perfect world.

Here is another link to Malt Specifications and what they mean and how to use them.

It would be nice if we (us AHB'ers) could develop a "Convention" or standardised way of reporting, or at least defining what we are referring to.
When someone says I got 73% efficiency - one is left to speculate on wether they had a moderately good Extract Efficiency or a stunningly good Brewhouse Efficiency.

Just posting "I got 72% EE would help; or 65% BE rather than the naked numbers.

Not much chance, too many bloody-minded individuals.
But we can hope - then we can work on getting rid of Pounds, Ounces, Gallons, SRM and the use of the words Color and Larger.

MHB


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## Thirsty Boy (3/12/07)

A while ago there was a rather extensive post about trying to get people to standardise the way they talk about efficiency. For exactly the same reasons that you are talking about MHB.

There was a bit of to and fro about the fact that people like to use Brewhouse efficiency vs those who like to use Extract efficiency, each thought the others method was too hard/not relevant to them/only for use by fools.... The outcome was that we should probably just at least post what sort of efficiency we are talking about - exactly as you suggest. I believe that after the argument was over.... everyone forgot about it and just went back to exactly what they were doing before 

There was though, a bit of confusion with the terms brewhouse / extract efficiency as well.. people using the same term to describe different things, which has happend in this thread already. I I took the whole thing to heart and and now when I refer to efficiency, I always explain what I mean, but try to avoid the terms extract and brewhouse, because not everyone is thinking the same thing when you say those words.

So I may refer to a recipe as being based on "75% _into the boiler_" which is wghat I would think of as extract efficiency. Whereas if I said "75% _into the fermentor_" that would be brewhouse efficiency. Really its just a bit of a clue so that other people can work out what the hell I am talking about.

Strangely enough, while Zwickel seems to be the only one in this discussion who is using the efficiency based on weight of grain thing... thats how I suspect a lot of people who "dont worry about efficiency" actually do worry about efficiency. They know that X kg of grain gives them Y points of gravity and how to calculate for increases or decreases... they just never converted the numbers into an efficiency figure.

I'm with you, I think that including an explanation would make everyones life a little easier... now all we have to do is convince the other 5000 posters to agree with us  

Thirsty


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## Sammus (3/12/07)

I agree. I don't care what kind of efficiency you talk about just so long as you say what it is! (even then its only to compare to my own haha)

The only one I dont like is the sugar/weight of grain efficiency - it doesnt make sense to me to label it an efficiency, since 100% can't possibly be attained - it should be theoretically plausible (but still not usually possible) to be 100% efficient.


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