calculating efficiency beersmith vs by-hand

[mummasan]

I don’t have beersmith so I have been doing my efficiency calculations by hand using Palmer’s book ‘How to Brew’ as a guide. Recently, when I asked a brewing buddy to put a recipe into beersmith I discovered that my hand calculations don’t match beersmith’s numbers. I’m sure I am doing something wrong and I would like to figure out what it could be. I was hoping another brewer could help me out.

This is the recipe: 7.5 lbs maris otter, 3.5 lbs two-row and 1.5 lb wheat – collected 6.5 gallons of wort and had a 1.060 BG gravity.

In one of the chapters in Palmer’s book, What to expect when you’re extracting, he assigns points to various grains. For max efficiency, he gives 38 points for two-row, 37 points for wheat and he does not assign a value for Maris Otter so I guessed 37 for Maris. Palmer says to multiply the points per pound then divide by the amount of wort collected into the kettle (38 x 3.5, 37 x 9 = 466 then divide by 6.5 = 71.6). Palmer says this is the max extraction efficiency from these grains – 1.071. (Someone let me know if I am wrong).

The 6.5 gallons of wort that I collected in my kettle had a BG of 1.060. Palmer says to divide 60/71 and you get your efficiency – for this brew day I calculated 84.5% efficiency.

The beersmith calculation my brewing buddy did said I got 73% efficiency. That is quite a difference. What am I doing wrong?

Palmer also indicates that you can calculate your efficiency by points per gallon. I calculated that with 12.5 lbs, collecting 6.5 gallons into my kettle and a OG of 1060 I got 31 points per gallon from my mash. Apparently anything over 30 is good. Does anyone else calculate their points per gallon? Have I calculated this wrong too?

 

[Kaiser]

Make sure that 6.5 gal is set as the batch size in Beersmith Then the brewhouse efficiency should match what you have.

Also check the extract % numbers that Beersmith has for the grains. They should be around 80%. But my guess is that it is taking the wrong volume for the efficiency calculation.

~85% efficiency is what I came up with. So you seem to be on the right track.

Kai

 

[mummasan]

Its good to know I'm on the right track...even though I have never liked math I enjoy calculating my efficiency and IBUs because it all relates to beer!

 

[FlyGuy]

Your hand calculations are fine. I think your problem is how you are using/interpretting Beersmith.

Beersmith calculates efficiency a few different ways. Which one did you use? Most people use the calculation based on Beersmith's predicted target volume (this is the volume of wort AFTER boiling and cooling -- i.e. batch size) and their post-boil gravity. I suspect your buddy may have confused something here (e.g., used your post-boil volume but entered the pre-boil gravity). That is easy to confuse -- in fact I think even Kaiser did that above (your batch size to be entered into Beersmith was probably something like 5.5 gals, NOT 6.5 gals which is the pre-boil volume).

Also note that he may have calcluated Brewhouse efficiency based on volume and gravity into the fermenter. If he did this, then this calculation takes kettle losses into consideration as well (e.g., losses of wort in the kettle, in the chiller, or to hop absorption). Your hand calculation does not do this, and if you have an significant losses going to the fermenter, it would not be surprising to see a 10% loss in efficiency. That could be correct.

Beersmith also has a tool to calculate your pre-boil efficiency in a way similar to your hand calculations, and that should be most comparable. Tell your buddy to go into the recipe (Recipe View) and click on the button labeled Brewhouse Efficiency. I dialog will pop up, and look to the middle for the section labeled 'Efficiency into Boiler'. Enter in your pre-boil volume (6.5 gal) and pre-boil gravity (1.060). Based on your recipe, Beersmith tells me that your efficiency was 83.3%. The small difference here is due to slightly different yields in Beersmith and rounding errors.

 

[mummasan]

Thanks for the detailed response.

On another note, I used your pictures of the 'Cheap 10 gal cooler MLT' to build my MLT. So far mine works great! Thanks.

 

[FlyGuy]

Thanks for the detailed response.

On another note, I used your pictures of the 'Cheap 10 gal cooler MLT' to build my MLT. So far mine works great! Thanks.

Glad you found both helpful! Cheers!

 

[Indyking]

This is an old thread and the problem seems to be resolved, thanks to the nice response by FlyGuy; however, I need help with the same topic if someone can help me.

My question is simple. How do I know the amount of wort collected into the kettle (boiler) to be able to calculate the efficiency? Is it the same as the amount of water going into the system during mashing and sparging? If yes, how about the water losses during the process (since the grains absorb some water and the mash tun may retain some too depending on the system)?

If I put 6.5 gallons of water in the system to mash and sparge, I will never be able to recover the same 6.5 gal, so what volume should I use for calculating efficiency? It's not possible to measure the amount of wort in my kettle, so I'm not sure!

 

[Jesper]

It's not possible to measure the amount of wort in my kettle, so I'm not sure!

Make yourself a measuring stick and use it to estimate the volume in your kettle with a fair accuracy.

If your kettle is really odd shaped so it's practically impossible to calculate volume based on the level on your measuring stick you can pour a gallon of water into your kettle, make a mark on your stick where the level is, pour another gallon of water into you kettle, make another mark on your stick etc.

 

[Indyking]

Make yourself a measuring stick and use it to estimate the volume in your kettle with a fair accuracy.

If your kettle is really odd shaped so it's practically impossible to calculate volume based on the level on your measuring stick you can pour a gallon of water into your kettle, make a mark on your stick where the level is, pour another gallon of water into you kettle, make another mark on your stick etc.

That's a good idea but after hearing a podcast by John Palmer, it seems that, in order to calculate efficiency, we should always take into consideration the amount of water poured into the system (mash plus sparging) and never the amount collected in the kettle (boiler). The reason for that is because efficiency is also a measure of how much of the water added was recovered as wort through the system. In fact, according to what I understood, one of the most common causes of poor efficiency is wort retention in dead spaces created in the mash tun due to a poorly configured system or poor handling of the grain bed during infusion. That makes sense. Did I understand everything correctly?

 

[Walker]

we should always take into consideration the amount of water poured into the system (mash plus sparging) and never the amount collected in the kettle (boiler). The reason for that is because efficiency is also a measure of how much of the water added was recovered as wort through the system. In fact, according to what I understood, one of the most common causes of poor efficiency is wort retention in dead spaces created in the mash tun due to a poorly configured system or poor handling of the grain bed during infusion. That makes sense. Did I understand everything correctly?

There are many different "efficiencies" that people measure.

Measuring the amount of wort in the kettle is how you get your overall "brewhouse" efficiency. That number factors in your volume losses in the tun.

 

[Jesper]

That's a good idea but...

I'm by no means an expert on efficiency calculations, but as walker says there's different kinds of efficiencies. Mash efficiency, brewhouse efficiency... To get the efficiency figure in BeerSmith "right" you need to spend some time filling in the equipment profile correctly, lautertun deadspace, evaporation per hour, estimate you average amount lost to trub, in hoses etc...

My reply were actually only meant as a solution to the question: "How do I know the amount of wort collected into the kettle (boiler) to be able to calculate the efficiency?"

 

[Indyking]

I'm by no means an expert on efficiency calculations, but as walker says there's different kinds of efficiencies. Mash efficiency, brewhouse efficiency... To get the efficiency figure in BeerSmith "right" you need to spend some time filling in the equipment profile correctly, lautertun deadspace, evaporation per hour, estimate you average amount lost to trub, in hoses etc...

My reply were actually only meant as a solution to the question: "How do I know the amount of wort collected into the kettle (boiler) to be able to calculate the efficiency?"

I see your point.

However, most of the time people talk about efficiency they are referring to mashing efficiency, i.e. based on the OG of the wort before boiling. That’s what really matters. There is very little one can do to improve "brewhouse" efficiency during boiling. What always confused me and I’m still not sure about is what volume we should take into consideration to calculate the mash efficiency since the volume of wort collected always is lower than the volume of water added to the system. Nobody seems to have a definitive answer with a good reference. Like I said, John Palmer touched based with this subject in the podcast I listened recently, but he didn’t quite confirm what I concluded, so I’m looking for more corroborative evidence that we should always take into consideration water added to the system when calculating mash efficiency.

I know someone who claims a minimum 90% mash efficiency every time with his system, then I realized he uses the wort volume for his calculations, which overestimates efficiency since it ignores wort lost to the system and absorbed by the grains. He transfers his pre-boiled wort to a volume-graded pail he built to measure its amount.

 

[Jesper]

Indeed mash efficiency is interesting and important as this is where you are most likely to have variations depending malt, crush etc. The rest are more or less constant.

Honestly, I not sure which kind of efficiency Beersmith works with and frankly, I'm not that concerned. I use Beersmith for all my recipe formulation and with my efficiency number dialed in, I'm able to approximate my boil volume, boil gravity etc. to be able to hit my target volume and O.G. consistently. Mostly at least.

I guess what I'm trying to say is that whether my mash efficiency is 65% or 80% isn't important to me as I don't compete in mash efficiency. I'm more concerned about having a consistent efficiency from brew to brew. With my efficiency dialed in in Beersmith I'm able to take a recipe from another brewer and scale/adjust it to my brew system to roughly hit a target O.G. and a specific volume on first attempt...

I understand this is not what you are looking for... but to calculate any efficiency you need to be able to measure volumes etc. accurately. Calculation based on estimates are worthless so you definitely need to know how much wort you are collecting at a specific gravity from a certain amount of grain.

 

[Indyking]

I guess what I'm trying to say is that whether my mash efficiency is 65% or 80% isn't important to me as I don't compete in mash efficiency. I'm more concerned about having a consistent efficiency from brew to brew. With my efficiency dialed in in Beersmith I'm able to take a recipe from another brewer and scale/adjust it to my brew system to roughly hit a target O.G. and a specific volume on first attempt...
.

Quite interesting. So, you always dial in a constant efficiency, I suppose in the field for brewhouse efficiency in beersmith, and work from there? How did you figure out that constant efficiency number to begin with?

 

[Jesper]

A mix of hard work and trail and error

First I spend some time setting up my equipment profile. I measured my loses in the lauter tun, hoses, pump, trub etc., then measured my evaporation rate over a couple of brews to dial in an average.

Now I'm doing my recipes based on 72% efficiency in Beersmith. In reality it differs between 70-74% as the amount lost in trub differs depending on hop additions, mash efficiency is slightly lower for high gravity beers (probably because I sparge a little less to hit my boil gravity instead of boil volume...)
Also I brew out door so my rolling boil isn't always consistent. As a consequence my evaporation rate differs slightly... small stuff, but gets me close enough to end up with roughly 11 gal. in the fermenter at the end of a brew day. If I miss my O.G. target it's normally not more than 1 point, but sometimes my final volume is a bit off.