Efficiency question

Today I made an all grain brew. Ten UK pounds of crushed pale malt were mashed at 67.5 deg C in six UK gallons of water. After one hour I ran off the liquor fly sparging with a further three UK gallons of water. The last runnings were 6.0 Brix = 1.015 SG. After boiling 30 minutes without hops and 60 minutes with various hop additions I ended up with 5.5 UK gallons with a BRIX of 10.0 which is approx 1.040 SG. Can anyone tell me what this is in efficiency terms, and assuming best possible expected efficiency, how much more SG could I attain. Many thanks.

Long and short is (5.5*40) / 10 = 22 points

Pale malt is 37 I think.

22/37 = 59-60%

Not great but you probably lost some wort to hops and just left behind. To get a more accurate reading, take a pre-boil reading where you have more accurate volume data.

ty as last runnings were 1.015 I clearly left some in the grain ....

UK gallons != US gallons. 5.5 UK gallons is 6.6 US gallons.

According to beersmith, (i don't know how to do the math by hand :-/), you got 74% efficiency. That's pretty darn decent.

Edit: OH, got it. 6.6 US gallons * 40 gravity points / 10 lbs = 26.4 points.

Pale malt is 36 ppg, (points per US gallon), so 26.4/36 = 73.3%

(Note, if you want to stay in UK units,, 36 points per US gallon is 30 points per UK gallon, so the math could also be 5.5 * 40 / 10 = 22 points, 22/30 = 73.3%)

Ah...that makes it a lot better. Nice catch Shorty.

ty shorty out of interest beer was just pale malt and amarillo hops....

Sounds yummy, a nice simple SMaSH....and Amarillo are some of my favorite hops

Just a couple of minor points.
The extract potential of UK pale malts is usually about 37 - 38 points per US gallon, or about 31 points per imperial gallon.
A Brix reading of 10.0 converts to a SG of 1.038.
That would give you an efficiency of 67%, which isn't too bad.
You could probably improve your efficiency with a thicker mash. If you mashed with 3 imperial gallons, and sparged with 6 gallons, you would end up with the same amount of wort, and probably get better efficiency as you would be rinsing the grains more with the extra sparge water. That would still be a fairly thin mash. I would mash with just over 2 imperial gallons (which is about as thick as you can go), but this takes a bit more effort to stir the mash and break up the dough balls.
With a bit of practice, you should be able to increase your efficiency up to about 80% (or more) which would give you a gravity of >= 1.045 for a 5.5 imperial gallon batch with 10 lb pale malt.

-a.

ERROR shame on all of us for not spotting it. 6 Brix = 1.024 SG. I mistakenly converted as though it started at Brix 10 and had fermented down to Brix 6, ie allowing for the effect of alcohol on the refractometer reading. My efficiency could potentially be improved a bit if I let more liquor drain out before starting fly sparging, anyway thanks to all contributors. I am going to repeat this brew next week but with cascade hops, to see if the difference is discernible.

Yes, 6 brix is about 1.024 which indicates that you are not using enough sparge water.
I've never drained any wort before starting the sparge, but I did get a 10% increase in efficiency when I started doing a mash out. Initially, I thought it was because of the increased grain bed temperature during the sparge, but now I think it was because of the stirring of the mash out water before starting the sparge.

-a.