Calculating Efficiency

[redrocker652002]

Ok, so the coffee kicked in, and I just cannot stay away for too long. LOL. So, I had 10 pounds of Extra Pale 2 row malt and 12 ounces of Crystal 15. I mashed at about 150 to 152 for 60 mins. My OG was at about 1.051 to 1.052. How can I calculate the efficiency on that I want to get to know that number so I can start adjusting my grain bills to fit what I am getting out of it. Any help would be most appreciated. Rock On!!!!!!!

 

[BrewnWKopperKat]

I'll offer this as a starting point for discussion. PPG numbers may not be exact

Gravity points may be the hidden (and some what abstract) concepts.

• Gravity points are the amount of fermentable "stuff" in the wort.
• Gravity points are constant. Specific gravity changes based on wort volume.

Malts (and sugars) are described in PPG (gravity Points per Pound of malt per Gallon of water).

Grains have a maximum potential PPG. Base malts are often 36 PPG. If efficiency were 100%, a pound of base malt would yield 36 gravity points. 36 gravity points in 5 gal of water is roughly SG 7.

At 100% efficiency the grain bill creates 384 gravity points

• 10 lb Extra Pale @ 36 PPG = 360 gravity points
• .75 lb Crystal 15 @ 32 PPG ) = 24 gravity points
• PPG will vary slightly based on brand of malt.

The actual gravity points created are 250 (5 gal * 50 SG)

250 / 384 = 65%

 

[DBhomebrew]

There's conversion efficiency and there's also mash efficiency which multiplies conversion efficiency with lauter efficiency. Then there's brewhouse efficiency, a whole other thing. Best to be specific about which one you're talking (or reading) about when.

You'll want fairly accurate volumetric data. The scale on the side of most kettles with 1/2 or 1/4G gradations is not accurate enough for very useful efficiency data. All volumes corrected to room temp.

 

[Clint Yeastwood]

It's funny, but I've never thought much about this. I just get the OG where I want it and then ferment. Then Beersmith tells me the efficiency, and I don't pay any attention to it. Maybe I should read up.

 

[DBhomebrew]

I don't worry about my efficiencies. I gather information about a batch as I brew it and however it comes out, that's how it comes out.

Over time I gathered really good information about a few dozen batches. Some high gravity, some low, many medium. Now, I can trust my recipe predictions to the point that as I get near the boil the surface of the FWH cap just touches the top edge of the kettle. My pre-boil volumes are spot on, within a couple  ounces. Gravities are within 1-2 points.

Again, I don't stress about the numbers. I gather them, crunch them, and use them so I don't have to. The beer in the kettle is the beer I designed in software. That's not important to many brewers.

 

[Bobby_M]

It's funny, but I've never thought much about this. I just get the OG where I want it and then ferment. Then Beersmith tells me the efficiency, and I don't pay any attention to it. Maybe I should read up.

The only people that worry about it are those who don't get anywhere near their expected OG.

 

[BrewnWKopperKat]

Published recipes are often standardized on certain measurements (volumes, efficiencies, ...). For example, BYO Recipe Standardization.

Also, this BYO article (link, from 2005) may be of interest.

 

[Clint Yeastwood]

Seems like brewing always gets more complicated; never less.

So far, since my return to brewing, I've ended up with one batch that was slightly undersized, for reasons I still don't know. Other than that, the wort is always at or above the target OG, and if it's over, I just dump water into the machine until I get the figure I want. I have ended up with more than 5 gallons of wort a time or two. I suppose this has some small effect on the bitterness, since the boil is finished, but I'm sure I can't tell the difference between 30 IBU and 33.

I don't know if I'm doing it wrong or what. I like the beer, though.

 

[DBhomebrew]

I don't know if I'm doing it wrong or what.

Numbers would help answer that question.

I like the beer, though.

If the variances and unpredictability of your process and product don't bother you, carry on!

 

[BrewnWKopperKat]

Seems like brewing always gets more complicated; never less.

I see it differently - but this the wrong place to discuss it. Curious? start a new topic.

 

[BeerHolic]

Following is an extract from John Palmer's "How to brew" 1st addition.

Planning Malt Quantities for a Recipe

We use the efficiency concept in reverse when designing a recipe to achieve a targeted OG. Let's go back to our Short Stout example.

To produce a 1.050 wort, how much malt will we need?

1. First, we need to assume an anticipated yield (e.g. 30 ppg), for the recipe volume (e.g. 5 gallons).
2. Then we multiply the target gravity (50) by the recipe volume (5) to get the total amount of sugar. 5 x 50 = 250 pts.
3. Dividing the total points by our anticipated yield (30 ppg) gives the pounds of malt required. 250 / 30 = 8.3 lbs. (I generally round up to the nearest half pound, i.e. 8.5)
4. So, 8.5 lbs. of malt will give us our target OG in 5 gallons. Using the malt values for 85% Efficiency in Table 9, we can figure out how much of each malt to use to make up our recipe.

Malts	OG based on PPG (85%)
6.5 lbs. of 2 Row	31 x 6.5 / 5 = 40.3
0.5 lb. of Chocolate Malt	24 x .5 / 5 = 2.4
0.5 lb. of Crystal 60	29 x .5 / 5 = 2.9
0.5 lb. of Dextrin Malt	28 x .5 / 5 = 2.8
0.5 lb. of Roast Barley	22 x .5 / 5 = 2.2
8.5 lbs. total	50.6 points total

Remember though that this is the post-boil gravity. When you are collecting your wort and are wondering if you have enough, you need to ratio the measured gravity by the amount of wort you have collected to see if you will hit your target after the boil. For instance, to have 5 gallons of 1.050 wort after boiling, you would need (at least):
6 gallons of 1.042 (250 pts/6g) or
7 gallons of 1.036 (250 pts/7g)

So, when planning to brew with grain, you need to be able to figure how much malt to use if you are going to collect 6-7 gallons of wort that will boil down to 5 gallons at a target OG. (Actually you need 5.5 gallons if you plan for fermentation losses from the hops and trub.) These considerations are taken into account in Chapter 19 - Designing Recipes.

 

[BrewnWKopperKat]

@BeerHolic: What you copied from the web site explains how to use efficiency to estimate OG.

OP wants to know how to calculate efficiency for OPs system.

---

eta: ... and yes, both calculating efficiency(s) and estimating OG be done with recipe software. What may missing from recipe software is the concept of "gravity points". What may "obscured" by recipe software is PPG for malts.

The calculations are not complex, although the equations do include 'units of measure' .

 

[BeerHolic]

@BeerHolic: What you copied from the web site explains how to use efficiency to estimate OG.

OP wants to know how to calculate efficiency for OPs system.

---

eta: ... and yes, both calculating efficiency(s) and estimating OG be done with recipe software. What may missing from recipe software is the concept of "gravity points". What may "obscured" by recipe software is PPG for malts.

The calculations are not complex, although the equations do include 'units of measure' .

Oops, my bad.
You did actually answer what was asked.

 

[BrewnWKopperKat]

Oops, my bad.

No worries; I wanted to help OP minimize the amount of stuff that OP needs to read to answer OPs question.

 

[redrocker652002]

Following is an extract from John Palmer's "How to brew" 1st addition.

Planning Malt Quantities for a Recipe

We use the efficiency concept in reverse when designing a recipe to achieve a targeted OG. Let's go back to our Short Stout example.

To produce a 1.050 wort, how much malt will we need?

1. First, we need to assume an anticipated yield (e.g. 30 ppg), for the recipe volume (e.g. 5 gallons).
2. Then we multiply the target gravity (50) by the recipe volume (5) to get the total amount of sugar. 5 x 50 = 250 pts.
3. Dividing the total points by our anticipated yield (30 ppg) gives the pounds of malt required. 250 / 30 = 8.3 lbs. (I generally round up to the nearest half pound, i.e. 8.5)
4. So, 8.5 lbs. of malt will give us our target OG in 5 gallons. Using the malt values for 85% Efficiency in Table 9, we can figure out how much of each malt to use to make up our recipe.

Malts	OG based on PPG (85%)
6.5 lbs. of 2 Row	31 x 6.5 / 5 = 40.3
0.5 lb. of Chocolate Malt	24 x .5 / 5 = 2.4
0.5 lb. of Crystal 60	29 x .5 / 5 = 2.9
0.5 lb. of Dextrin Malt	28 x .5 / 5 = 2.8
0.5 lb. of Roast Barley	22 x .5 / 5 = 2.2
8.5 lbs. total	50.6 points total

Remember though that this is the post-boil gravity. When you are collecting your wort and are wondering if you have enough, you need to ratio the measured gravity by the amount of wort you have collected to see if you will hit your target after the boil. For instance, to have 5 gallons of 1.050 wort after boiling, you would need (at least):
6 gallons of 1.042 (250 pts/6g) or
7 gallons of 1.036 (250 pts/7g)

So, when planning to brew with grain, you need to be able to figure how much malt to use if you are going to collect 6-7 gallons of wort that will boil down to 5 gallons at a target OG. (Actually you need 5.5 gallons if you plan for fermentation losses from the hops and trub.) These considerations are taken into account in Chapter 19 - Designing Recipes.

This actually helps a lot. It gives me a base to work with thank you. I am guessing the numbers may change if the system efficiency is different though, right? Say I am only at 65%, would the numbers change?

 

[redrocker652002]

Published recipes are often standardized on certain measurements (volumes, efficiencies, ...). For example, BYO Recipe Standardization.

Also, this BYO article (link, from 2005) may be of interest.

OK, so I am confused. I added my fermentables and how much into the calculator. It gives you the list of which companies and which grains, so I did that as well. 5 gallons in the fermentor and it gives me a efficiency of about 70%. So, I am guessing, and just kinda thinking out loud, I can figure about 65 to 70% when I am building or scaling my recipes to the original recipe I have? This is fun, because I dig the numbers and reasoning to why. Thanks to all who had input. I appreciate it. Rock On!!!!!!!

 

[BrewnWKopperKat]

it gives me a efficiency of about 70%.

If you want to look deeper into the differences in the calculations, what were the PPM values for each of the malts in the calculator? If I change the values in #2 from 36 & 32 to 35 & 30, I get roughly 67%.

I can figure about 65 to 70% when I am building or scaling my recipes to the original recipe I have?

That will be a good starting point for the next recipe.

This is fun, because I dig the numbers and reasoning to why.

I agree. In school, I never liked story problem math ("Johny has three apples, Suzie has six, ... ?"). Then I learned to home brew!

 

[redrocker652002]

If you want to look deeper into the differences in the calculations, what were the PPM values for each of the malts in the calculator? If I change the values in #2 from 36 & 32 to 35 & 30, I get roughly 67%.


That will be a good starting point for the next recipe.


I agree. In school, I never liked story problem math ("Johny has three apples, Suzie has six, ... ?"). Then I learned to home brew!

That would be a good suggestion. I will have to look into that again and see. I am guessing the number is listed in the product page in MoreBeer or some of those places?

 

[DBhomebrew]

5 gallons in the fermentor and it gives me a efficiency of about 70%

What kind of efficiency?

You really do want to separate the various efficiencies out for best understanding of your system/process and how recipes interact with them.

How you adjust for lower than typical mash efficiency is not the same as how you adjust for lower than typical brewhouse efficiency. If it's lauter efficiency that's the issue, you very well may just accept it, if it's consistent. If you find your conversion efficiency is rather low (<~95%), you'll likely want to fix it.

In the end, you'll get to the point where the source recipe's water volumes and grain weights don't concern you at all. You'll see a recipe and take its grist (by %) and OG. Exactly how much water and grain to use will be derived by your software using actual observed and measured system stats such as grain absorption, transfer losses, boil-off rate, etc. The recipe gives you the goal for the wort in the fermenter and how the author got there on their system. With understanding of what's under the hood of 'efficiency', you'll have the tools to get to the end goal on your system with your process.

Conversion efficiency
Lauter efficiency
Mash efficiency
Brewhouse efficiency

Each type of efficiency provides very useful information about very different parts of your brewday. Brewhouse arguably being the least useful.

 

[BrewnWKopperKat]

I will have to look into that again and see. I am guessing the number is listed in the product page in MoreBeer or some of those places?

It's a good place to start looking. Occasionally the number can be found product information sheets (or calculated from data in those sheets). eta: recipe software also has the number.

 

[redrocker652002]

Thanks to all who posted. I am thinking this is going to be more than I expected to learn, but will keep trying. Using my OG and grain numbers, I came out with about 68% brewhouse efficiency I think it was. I will check it again. My hope is to get that a bit higher. I think next time I am going to split my dunk sparge in half and do two dunks. I might even just use the whole sparge amount and just pour it thru the grain like a lautering and see if that helps. Either way, my numbers have been ok so far. Not spot on, but within a point or two, so I am ok with that so far. But, I dig just trying to figure out where I am and where I could possibly be. So, thanks to all, and keep it coming. Rock On!!!!!!!

 

[RM-MN]

Things to consider to increase efficiency:
1. Efficiency is most influenced by the quality of the crush. If you don't own the mill, don't expect high efficiency nor should you expect consistent efficiency.
2. Sparging will increase efficiency but not by a huge amount. If the crush is bad, sparging will not overcome the deficiency.
3. If the crush is poor, a longer mash may be needed to get closer to complete conversion.
4. Any wort left in the boil kettle reduces efficiency. Trying to leave the trub behind when you transfer also leaves behind wort.
5. Efficiency isn't very critical in home brewing as you can make up poor efficiency by adding only a small amount of extra base malt.

 

[BrewnWKopperKat]

I came out with about 68% brewhouse efficiency I think it was. I will check it again.

Consistent efficiency is more important than the percentage.

If/when you decide to improve the percentage, the measurements that @DBhomebrew mentioned can be helpful. You mentioned "dunk sparge" which suggests you are BIABing - if so, the places to measure efficiency may be different from a "mash tun" brewing process.

 

[DBhomebrew]

Things to consider to increase efficiency:
1. [Conversion] Efficiency is most influenced by the quality of the crush. If you don't own the mill, don't expect high efficiency nor should you expect consistent efficiency.
2. Sparging will increase [lauter] efficiency but not by a huge amount. [1 really good dunk sparge gains ~8% lauter efficiency compared to full volume mash] If the crush is bad, sparging will not overcome the deficiency [in conversion].
3. If the crush is poor, a longer mash may be needed to get closer to complete conversion [>95%].
4. Any wort left in the boil kettle reduces [brewhouse] efficiency. Trying to leave the trub behind when you transfer also leaves behind wort.
5. [As long as it's consistent,] Efficiency isn't very critical in home brewing as you can make up poor efficiency by adding only a small amount of extra base malt.