Mash efficiency in Beersmith

[pretzelb]

If I were to tell Beersmith that my efficiency was 100% and took note of the estimated gravity for pre boil, then compared that to my actual, would the percentage difference be my mash efficiency?

 

[dmtaylor]

If you remove the 1.0 from the front of it, then yes, exactly. For example, if at 100% you expect 1.045 but actually only get 1.030, then your efficiency is 30/45 = 67%.

 

[pretzelb]

I've been playing with the numbers and something isn't working. If I tell BS that my BH efficiency is 100% then it thinks my mash efficiency will be over 100%. If I lower my BH efficiency to 91.3% then my mash efficiency ends up at 100%. To make things more confusing, the estimated preboil gravity for 100% mash efficiency doesn't add up to the calculation I do by hand.

I'm looking at a recipe and I think the estmated max points is 897.75. Then if I look at a preboil volume of 13.58 that should be a 1.066 estimate for preboil gravity. But BS is the estimated preboil is 1.068. Not off by a huge amount but it should be a simple calculation.

Max Points Pounds Max Points Est Max PPG
Pale Malt (2 row) 36 22 770 56.70
Caramel Wheat 35 1 34 2.50
Munich Malt 37 1 36 2.65
Victory Malt 34 1 33 2.43
Peat Smoked Malt 34 0.75 24.75 1.82
Total 25.75 897.75 66.11

 

[dmtaylor]

I must confess I don't subscribe to BS so hopefully someone else can explain how the brewhouse efficiency is calculated from mash & lauter efficiency. There should be a setting in there someplace for lauter efficiency and you might be missing that.

 

[day_trippr]

There are a bunch of threads discussing BS "efficiency" metrics.
Some of them are linked at the bottom of this page, and if you follow a good one it'll lead to others.

Mash efficiency should be non-controversial as it's too simple to calculate correctly.
But let's just say there are lots of people that don't agree with the BS brewhouse efficiency method...

Cheers!

 

[pretzelb]

There are a bunch of threads discussing BS "efficiency" metrics.
Some of them are linked at the bottom of this page, and if you follow a good one it'll lead to others.

Mash efficiency should be non-controversial as it's too simple to calculate correctly.
But let's just say there are lots of people that don't agree with the BS brewhouse efficiency method...

Cheers!

I've spent a few hours each day this weekend just reading and working on spreadsheets. I suppose I can count this contributing to the hobby but somehow it seems like wasted time. But I think I'm finally close to a point where I get it.

FWIW I started a thread in the BS forums and one response was if you zero out the estimates for volume losses then 100% brew house eff will result in 100% mash eff estimates. I had someone else try to tell me that 100% mash eff would result in extract more than the potential SG of each grain. I'm still trying to figure that one out. I also added a thread to the suggestions forum that having the user enter a mash eff would be much more useful and easier to debug than having them enter the BHE. I really fail to see how BHE is a better metric to enter.

 

[Oginme]

I've been playing with the numbers and something isn't working. If I tell BS that my BH efficiency is 100% then it thinks my mash efficiency will be over 100%. If I lower my BH efficiency to 91.3% then my mash efficiency ends up at 100%. To make things more confusing, the estimated preboil gravity for 100% mash efficiency doesn't add up to the calculation I do by hand.

I'm looking at a recipe and I think the estmated max points is 897.75. Then if I look at a preboil volume of 13.58 that should be a 1.066 estimate for preboil gravity. But BS is the estimated preboil is 1.068. Not off by a huge amount but it should be a simple calculation.

Max Points Pounds Max Points Est Max PPG
Pale Malt (2 row) 36 22 770 56.70
Caramel Wheat 35 1 34 2.50
Munich Malt 37 1 36 2.65
Victory Malt 34 1 33 2.43
Peat Smoked Malt 34 0.75 24.75 1.82
Total 25.75 897.75 66.11

Let's start with correcting a basic issue with your maths. If you have a potential of 36 pppg and add 22 lbs, your expected points at 100% extraction is 792 points and not 770 points. This error carries down through your grains and should account for any difference you have from the BeerSmith calculation.

On you other comment about changing the fixed variable from BHE to ME, I would have written the software based upon the expected ME. The problem is when you have n+1 variables and N equations, one of the variables must be given a reproducible or best guess value. Brad chose BHE as that fixed variable. In reality, I find my ME to be more reproducible and therefore predictable but it is easy enough to compensate for when making a change to post mash volume losses.

 

[pretzelb]

Doh. The formula I entered in the spreadsheet was 1 - points * grains in lbs. I think I started with the SF values like 1.036 and was creating the formula to get the points then decided to just type the points in (36) but failed to change the formula. Ugh. Sadly I don't even think beer was involved.

 

[Oginme]

LOL, I can't count the number of times I forgot to update formulations when changing units or (even worse) prices. Just when you think you have it all covered...