Help me clear up a couple of "Beersmith Efficiency" questions please

Apologies in advance for this long post. I have just brewed my third all grain and I wonder if you could please help me.

The first couple of all grain brews were a matter of trying to make sense of the process which now I think I have a handle on.

I have put the numbers back into Beersmith and it is saying that I have a shocking 49.6% !!

I have a 33L Colemans extreme coolbox, and followed the proceedure for mashing, temperatures, and volumes for batch sparging to the letter. The equipment profile was set up for an estimated efficiency of 66%.

I hit my mash temperature of 66 degrees C and left it there for 90 minutes. After 90 minutes it had dropped to 62.6 degrees C

Grain bill was 2915g (only 13L batch).
The mash is ratio is 2.78Kg/Litre

First mash volume was 10L, SG 1040
Second mash volume was 10.8L, SG was 1.000

Beersmith estimated pre boil SG of 1.026, compared to 1.020
Measured volume prior to boil 20.8L, SG 1.020

Post boil volume was 13L (spot on from Beersmith)
Post boil SG was 1.040
Estimated SG was 1.043

Now whilst typing this and looking back over the data, I feel that I have made a basic mistake in the numbers, please correct me if I am wrong here.

When taking the measured pre boil SG, ie 1.020, it was taken at 64 degrees C, compared to the predicted SG, ie 1026.

Now, when this is corrected for temperature at 20 degrees C it comes out around 1.035, (against a predicted 1.026) which when put back into the Beersmith gives me a measured mash efficiency of 87%, rather than the 49.6% based on the input of 1.020.

The now measured efficiency in the design tab is 61.9%

Question:

1.Would you update the equipment profile to the new efficiency of 61.9% or leave as is for a few more brews?


Can somebody please help me here?

Sorry not quite finished, pressed return key by accident  :-[

Best regards,
WM7793

Was the post boil volume and SG taken post chill at 20C? If so, that'd be what I'd use for a basis of efficiency in BS. The program automatically calculates mash efficiency, so that's not what I'm addressing.

You can also do a reality check of your brewhouse efficiency with this formula:

BHE = (Sg x BV) / (Pg x GW)

BHE: Brew House Efficiency
Sg: Wort Specific Gravity, post chill (or post boil)
BV: Batch Volume, as measured in the fermenter
Pg: Potential gravity of grain (found by double clicking the ingredient, but 39 is a good starting number)
GW: Grain Weight

This formula simply divides the gravity points yielded into the fermenter by the total gravity point potential of grain (or extract or sugars) used.

As with all gravity calculations, the specific gravity 1.0 is dropped (1.040 becomes 40).

Thanks Brewfun for your reply, and for the information on the brewhouse efficiency formula. 

I have just checked my notes, and the temperature for these figures was taken at 24 degrees C.

Best regards,
WM7793

Brewfun, is the grain weight in the BHE formula, pounds, kg's ?

Best regards,
WM7793

WM7793 said:

Brewfun, is the grain weight in the BHE formula, pounds, kg's ?

Best regards,
WM7793

Click to expand...

Both. As long as you're not mixing standards, it should calculate the same.

Many thanks, Brewfun.

Best regards,
WM7793

brewfun said:

Pg: Potential gravity of grain (found by double clicking the ingredient, but 39 is a good starting number)

Click to expand...

Would Pg be an average for all of the grains used in your grain bill?

BeerSmith calculates gravity points on each grain individually, then sums it up for full potential.

An average is fine. I actually just use the number of the largest portion of the grist. The difference will be 1 or 2%, depending on how much specialty grain you're using.