Efficiency?

[yashicamat]

I am trying to calculate the efficiency of my new setup so I can more accurately formulate my recipes, so I was rather hoping someone could give me a hand with these numbers and check that I'm doing this right please?

Using John Palmer's guide on calculation, he states that the basic formula is:

(US gallons of wort collected x gravity points gained) / lbs of grain used

Then divide the number produced by the formula by 37 (and then multiplying by 100) to get the percentage efficiency.

OK perhaps not the friendliest of units, but conveniently my scales are in lbs and oz and it's easy enough to do the conversion to US gallons from imperial pints or litres.

The brew I did a few weeks ago came out at over 100% efficiency, which seemed ridiculous, but that was the top of the 25 litre grain bucket I use for grain storage so my guess is the last of the bag went into that one, so I ended up with more than the average amount of flour. That's why my 5.2% IPA ended up being nearly 7%.

Anyway, let's forget that one and concentrate on yesterday's brew (I really stirred up the grains in the bucket well as there is now some breathing space in there):

7.5 US gallons (50 pints) of wort was collected in total from the grains, doing a 90 minute mash with fly sparging.
The gravity of this at 20 deg C was 1037. A total of 9.5 lbs of grain went in (all pale 2-row perle).

So, plugging these figures into JP's equation:

(7.5 x 37) / 9.5 = 29.211

(29.211/37) x 100 = 78.95%, i.e., 79% efficiency.

Does this sound right? Another thing that has occured to me that maybe the gains made during the IPA have robbed me of some of the potential from the remaining grain as I took "their share" of the flour. Be interesting to see if the efficiency changes when I move into the second bucket (the 25kg sack was split between two).

Cheers.

[ade1865]

Try this thread: viewtopic.php?f=2&t=15174

AS for your numbers, sorry can't help, but I work out my efficency with the following equation, which could well be wrong;

%efficiency = (Vol of liquer X OG)/(296 X Kg grain)


Umm, hope that makes sense.

Think it yer pounds and US gallons that have me running for the hills

[clogwog]

I used to struggle with working it out manually, and eventually figured how to do it.

Then I bought BeerSmith, but other brewing systems should be able to do the same thing.

It calculates it all for me. It gives me my efficiency at various levels in my brewing system:
Efficiency into the kettle - tells me how good my mash/sparge process is.
Efficiency into fermenter - tells me what my losses are in what I left in trub the kettle.
Brewhouse Efficiency - tells me what my losses are in what's left behind in the fermenter post bottling/kegging.

If you still want to calculate it manually, this is how I did it:

Mash Efficiency

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

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%

Well, it's the method you will see in Australia.

Say the HWE is 308 litre degrees per kilogram for a malt.
That means 5kg in 20L will give you : (308 x 5)/20 = 77. i.e. 1.077 SG at 100% efficiency. Multiply that by your efficiency (eg. 75%) gives you 77 x 0.75 = 57.75 or close enough to 1.058.

[ADDLED]

Another bookmarked post.....
cheers for the knowledge.
Owen