Strike volume and efficiency issues...

[seatazzz]

So I am finally so frustrated with my crappy efficiency that I need help. Today I'm brewing an American Strong with the below grain bill:

14lbs double milled 2-row
2lbs special roast (also double milled)

Mashed at 156-157, recirculated a while to get temp down to 152, then left it alone for the rest of the 60 minute mash. Strike volume was high (probably about 9 gallons) and got 4.5 gallons first runnings at 1.051. NOT happy with that. Sparged with 5 gallons to get target preboil volume (90 minute boil) of 9.5 gallons, sparge came out at 1.032. Preboil wound up at 1.040 for what is supposed to be a bigger beer.

So my question is (and yes I'm too lazy to google it), did my higher strike water volume screw my efficiency? And why? I know I've read somewhere that using too much water will mess with the gravity, I just want to know why. I'm planning a SMaSH for next weekend with some brand new very expensive hops and don't want to mess it up. Thanks for any help.

 

[Dgallo]

So I am finally so frustrated with my crappy efficiency that I need help. Today I'm brewing an American Strong with the below grain bill:

14lbs double milled 2-row
2lbs special roast (also double milled)

Mashed at 156-157, recirculated a while to get temp down to 152, then left it alone for the rest of the 60 minute mash. Strike volume was high (probably about 9 gallons) and got 4.5 gallons first runnings at 1.051. NOT happy with that. Sparged with 5 gallons to get target preboil volume (90 minute boil) of 9.5 gallons, sparge came out at 1.032. Preboil wound up at 1.040 for what is supposed to be a bigger beer.

So my question is (and yes I'm too lazy to google it), did my higher strike water volume screw my efficiency? And why? I know I've read somewhere that using too much water will mess with the gravity, I just want to know why. I'm planning a SMaSH for next weekend with some brand new very expensive hops and don't want to mess it up. Thanks for any help.

Yes. Your gravity is directly linked to sugar extraction and water volumes. This is where your efficiency comes from. More water means the sugars you are extracting are less concentrated in your wort, meaning your gravity will be lower. You need a program to calculate the water volumes for you if you’re not going to do the math yourself. Download yourself beersmith and inn the mean time use this http://www.brew365.com/mash_sparge_water_calculator.php

Your water seems far off. For a 5 gal batch with 16 lbs of grain. I’m usually around 4.5 gallons of water and will yield just about 3 gallons of wort from the first running’s. My sparge will be near the same amount of volume and I’ll have roughly 6.75-7 gallons in the end.

 

[kevin58]

Try mashing lower too. You say you "mashed at 156-157, recirculated a while to get temp down to 152"... If 152 is your goal then calculate your strike water to hit that to start with. If you have to adjust to get there I personally would rather start a couple of degrees low and adjust upward rather than start high and go down.

 

[seatazzz]

Good answers, both. Yep I have gotten a bit complacent in my process and not paying attention to little things. Thanks guys.

 

[doug293cz]

So I am finally so frustrated with my crappy efficiency that I need help. Today I'm brewing an American Strong with the below grain bill:

14lbs double milled 2-row
2lbs special roast (also double milled)

Mashed at 156-157, recirculated a while to get temp down to 152, then left it alone for the rest of the 60 minute mash. Strike volume was high (probably about 9 gallons) and got 4.5 gallons first runnings at 1.051. NOT happy with that. Sparged with 5 gallons to get target preboil volume (90 minute boil) of 9.5 gallons, sparge came out at 1.032. Preboil wound up at 1.040 for what is supposed to be a bigger beer.

So my question is (and yes I'm too lazy to google it), did my higher strike water volume screw my efficiency? And why? I know I've read somewhere that using too much water will mess with the gravity, I just want to know why. I'm planning a SMaSH for next weekend with some brand new very expensive hops and don't want to mess it up. Thanks for any help.

9 gal strike and 4.5 gal first runnings means your grain absorption + undrainable MLT volume was 4.5 gal. 16 lbs of grain should absorb about 1.9 gal @ a 0.12 gal/lb absorption rate typical of traditional MLT's. That puts your MLT undrainable volume at a little over 2.5 gal, which is a ridiculously high value (should be less than 0.25 gal.) If these numbers are real, that's a big part of your efficiency problem.

Plugging all the numbers into my simulator, your first runnings should have had an SG of ~1.057, and the sparged wort should have been ~1.030, if you had gotten 100% conversion efficiency. The first runnings being low, and the second runnings being high is an indicator that starch conversion was not complete at the end of the mash, and continued some during the sparge. Assuming your pre-boil wort was adequately mixed leads to an estimated conversion efficiency of about 93%. Your lauter efficiency comes out about 73%, and mash efficiency about 67%.

If you got your undrainable volume down to 0.25 gal, and your conversion efficiency up to 95%, your numbers would look something like:

Strike volume: 6.92 gal
First runnings volume: 4.75 gal
First runnings SG: 1.069
Sparge volume: 4.75 gal
Sparge runnings volume: 4.75 gal
Sparge runnings SG: 1.027
Pre-boil volume: 9.5 gal
Pre-boil SG: 1.048
Lauter Efficiency: 84 - 85%
Mash Efficiency: 80 - 81%
​

To improve conversion efficiency you should crush your grain finer (get your own mill), and/or mash longer. Lauter efficiency is improved by reducing your undrainable MLT volume.

Brew on

 

[CascadesBrewer]

What is your batch size? 14 lbs of grain is a good amount for 5 gals of a big beer...but 9.5 is a lot of pre-boil volume for a 5 gal batch?

 

[Dog House Brew]

9 gal strike and 4.5 gal first runnings means your grain absorption + undrainable MLT volume was 4.5 gal. 16 lbs of grain should absorb about 1.9 gal @ a 0.12 gal/lb absorption rate typical of traditional MLT's. That puts your MLT undrainable volume at a little over 2.5 gal, which is a ridiculously high value (should be less than 0.25 gal.) If these numbers are real, that's a big part of your efficiency problem.

Plugging all the numbers into my simulator, your first runnings should have had an SG of ~1.057, and the sparged wort should have been ~1.030, if you had gotten 100% conversion efficiency. The first runnings being low, and the second runnings being high is an indicator that starch conversion was not complete at the end of the mash, and continued some during the sparge. Assuming your pre-boil wort was adequately mixed leads to an estimated conversion efficiency of about 93%. Your lauter efficiency comes out about 73%, and mash efficiency about 67%.

If you got your undrainable volume down to 0.25 gal, and your conversion efficiency up to 95%, your numbers would look something like:

Strike volume: 6.92 gal
First runnings volume: 4.75 gal
First runnings SG: 1.069
Sparge volume: 4.75 gal
Sparge runnings volume: 4.75 gal
Sparge runnings SG: 1.027
Pre-boil volume: 9.5 gal
Pre-boil SG: 1.048
Lauter Efficiency: 84 - 85%
Mash Efficiency: 80 - 81%
​

To improve conversion efficiency you should crush your grain finer (get your own mill), and/or mash longer. Lauter efficiency is improved by reducing your undrainable MLT volume.

Brew on

This^^^

 

[seatazzz]

Thanks guys. My MT has a fairly good-sized dead space under the false bottom (typically get 1+ gallons out of it). I do recirculate for the lauter, and the grain bill was double milled to pretty fine crush. I'm leaning far over on the side of too high strike volume. Fortunately I'll get a quick chance to brew again this weekend and prove theories.

 

[doug293cz]

Thanks guys. My MT has a fairly good-sized dead space under the false bottom (typically get 1+ gallons out of it). I do recirculate for the lauter, and the grain bill was double milled to pretty fine crush. I'm leaning far over on the side of too high strike volume. Fortunately I'll get a quick chance to brew again this weekend and prove theories.

Too high a strike volume will decrease your SG, but actually increase your efficiency a little.

Brew on

 

[catdaddy66]

I am also befuddled by my high gravity beers having lower than expected gravity numbers. This doesn't happen all the time but enough to irk me.

I have gleaned thru my research that, due to reduced efficiency, one should a) increase mash volumes and/or b) increase grain amounts. I opt for a) because it is the less expensive and easier variable to manipulate.

I will follow this thread to improve my process...

 

[catdaddy66]

Too high a strike volume will decrease your SG, but actually increase your efficiency a little.

Brew on

This was not what I expected with higher strike volume. So, I guess I am misunderstanding how to calculate efficiency to begin with...

Math!! Frigging farging varmint critter!

 

[dmtaylor]

Stop wasting gallons of wort by adding too much water, then miraculously your situation will improve, as stated previously.

 

[Dland]

Also, if you overdo the strike volume, you have less sparge volume available before you reach pre boil target volume. The lower sparge volume will adversely affect your efficiency. If you have trouble working the optimal volumes out, a brew program like Beersmith can be useful.

 

[doug293cz]

This was not what I expected with higher strike volume. So, I guess I am misunderstanding how to calculate efficiency to begin with...

Math!! Frigging farging varmint critter!

Math is confusing to many folks, but it is very helpful to understanding how variables affect process outcomes.

In general efficiency is how much you got compared to the maximum available. Efficiency is usually expressed as a percentage defined by: 100% * Actual Obtained / Max Available.

In brewing, efficiencies are about how much of the avialable extract (sugar) you collect vs. how much could be obtained from the grain (if you could get it all.) Volume only comes into play since we can’t directly measure the amount (mass or weight) of extract in wort - we can only measure the volume of wort, and its SG, and use that to calculate the amount of extract.

There are several efficiency measurements of interest in brewing:

• Mash Efficiency = Amount of Extract in BK / Max Potential Extract in Grain
• Mash Efficiency = Conversion Efficiency * Lauter Efficiency
• Conversion Efficiency = Amount of Extract Created in Mash / Max Potential Extract in Grain
• Lauter Efficiency = Amount of Extract in BK / Amount of Extract Created in Mash
• Transfer Efficiency = Amount of Extract in Fermenter / Amount of Extract in BK
• Brewhouse Efficiency = Mash Efficiency * Transfer Efficiency
• Brewhouse Efficiency = Amount of Extract in Fermenter/ Max Potential Extract in Grain

Note that none of the efficiency definitions involve volume, only the amount (mass or weight) of extract. It is possible to calculate the amount of extract if we know the volume of wort and its SG, however we can use a simpler approximation of amount of extract known as Points. One point will raise the SG of one gallon of wort by 0.001. Thus the number of points in one gallon of wort is:

Points / Gallon = 1000 * (SG - 1)​

Rather than doing the math, pts/gal is just taken as the three digits after the decimal point in the SG, and dropping any leading zeros. Thus wort with an SG of 1.037 has 37 pts/gal. You calaculate the total number of points in a volume of wort as: gal of wort * pts/gal, so 5 gal of wort with an SG of 1.037 has 5 gal * 37 pts/gal = 185 points.

We can also express the potential extract in grain in terms of points. Base malts usually contain about 37 points/lb of grain (commonly called points per pound per gallon or “ppg.”) This means that if 1 gal of wort is made with all of the possible extract from one pound of grain, then the wort would have an SG of 1.037. In grain databases, the extract potential is often given in SG rather than ppg, so the potential of a grain with 37 ppg would be listed as 1.037. Note that if you put all of the extract from 1 lb grain with a potential of 1.037 into 1 gal of water, you will have more than one gal of wort (since the extract has volume that adds to the total volume of wort), and the SG of the wort will be less than 1.037. This is a common point of confusion, which often leads to errors in calculating conversion efficiency.

We can use points to calculate efficiency. First we have to determine the number of potential points we start with in our grain bill. To do this we multiply the weight of each grain by the ppg of that grain, and add up the points for each grain. So, if we have 5 lb of grain with a potential of 1.037, and 5 lb with a potential of 1.035, then the total potetial points are 5 lb * 37 ppg + 5 lb * 35 ppg = 185 pts + 175 pts = 360 pts total extract potential. If we mash and sparge that 10 lb of grain with a total of 7.7 gal of water, and collect 6.5 gal of pre-boil wort at an SG of 1.045 then the number of points in our BK will be: 6.5 gal * 45 pts/gal = 292.5 pts. Using the equation for mash efficiency above, our mash efficiency will be: 292.5 pts / 360 pts = .8125 => ~81%.

If we boil that 6.5 gal of wort down to 5.5 gal, we will still have 292.5 pts of extract, since we only evaporate water during the boil, but no extract. The post boil wort will then have: 292.5 / 5.5 gal = 53.18 pts/gal => SG of ~1.053.

If we transfer 5.0 gal of the post-boil wort to the fermenter, then the fermenter will contain: 5.0 gal * 53 pts/gal = 265 points. Brewhouse efficiency then equals: 265 pts / 360 pts = 0.736 => 73.6%.

Now if we had used more brewing water (strike + sparge = ~8.51 gal), and collected 7.3125 gal of wort at 1.040 SG, our BK points would still be: 7.3125 gal * 40 pts/gal = 292.5 pts, and our mash efficiency still would have been ~81%. However, using more brewing water generally improves lauter efficiency, and therefore mash efficiency, so the collected wort would more likely have have an SG of about 1.041, giving BK points of 7.3125 * 41 = ~300 pts, for a mash efficiency of 300 pts / 360 pts => ~83%.

Brew on

 

[cloudybrewer]

Math is confusing to many folks, but it is very helpful to understanding how variables affect process outcomes.
Brew on

Doug, you should add Teacher to your list of accolades by your name. Your explanations are gold.

 

[doug293cz]

Doug, you should add Teacher to your list of accolades by your name. Your explanations are gold.

Thank you. That means a lot to me.

Brew on

 

[snarf7]

Stop wasting gallons of wort by adding too much water, then miraculously your situation will improve, as stated previously.

What about the flipside of this though? When you miscalculate and you don't start with enough water and you wind up short of your final volume? (e.g. targeting 5 gal and you wind up with 4 gal post-boil). Sometimes it's due to extra absorbent grains and/or a too rigorous boil leading to excessive evaporation. I always just add water to make it up and have never had any issues but does that have an impact on the gravity numbers?

 

[dmtaylor]

What about the flipside of this though? When you miscalculate and you don't start with enough water and you wind up short of your final volume? (e.g. targeting 5 gal and you wind up with 4 gal post-boil). Sometimes it's due to extra absorbent grains and/or a too rigorous boil leading to excessive evaporation. I always just add water to make it up and have never had any issues but does that have an impact on the gravity numbers?

Great question. Yes, the flipside matters as well. With experience, you should be able to nail your volume every time within say 1-1.5 quarts. If you can't, then keep on practicing, get better software, or both.

 

[Dgallo]

Great question. Yes, the flipside matters as well. With experience, you should be able to nail your volume every time within say 1-1.5 quarts. If you can't, then keep on practicing, get better software, or both.

Def important to get a feel for your equipment

 

[snarf7]

Great question. Yes, the flipside matters as well. With experience, you should be able to nail your volume every time within say 1-1.5 quarts. If you can't, then keep on practicing, get better software, or both.

How so exactly? I get that having too much water dilutes the overall solution and you wind up with lower gravity...but if you boil off too much isn't that just an overly concentrated solution that you just need to add water to so it balances out? Does having less water during the boil lead to less absorption of sugars or something like that?

 

[dmtaylor]

How so exactly? I get that having too much water dilutes the overall solution and you wind up with lower gravity...but if you boil off too much isn't that just an overly concentrated solution that you just need to add water to so it balances out? Does having less water during the boil lead to less absorption of sugars or something like that?

More good questions! If the cause of low volume is over-boiling, then yes you can just add water and not affect efficiency. However my point was more that if you under-sparge and that caused low volume, then you have left behind sugars in the grains that were intended to be collected and included, which will reduce the efficiency from what you had intended.

 

[snarf7]

More good questions! If the cause of low volume is over-boiling, then yes you can just add water and not affect efficiency. However my point was more that if you under-sparge and that caused low volume, then you have left behind sugars in the grains that were intended to be collected and included, which will reduce the efficiency from what you had intended.

I gotcha. Certainly better efficiency is always a good thing but perhaps even more important is knowing exactly what you will get with your equipment and technique. BIAB with no sparge you might only get 60-70% but if you know that's what you get consistently with that approach then you can adjust your grain bill to dial in the exact numbers you want.

 

[Soulshine2]

So I am finally so frustrated with my crappy efficiency that I need help. Today I'm brewing an American Strong with the below grain bill:

14lbs double milled 2-row
2lbs special roast (also double milled)

Mashed at 156-157, recirculated a while to get temp down to 152, then left it alone for the rest of the 60 minute mash. Strike volume was high (probably about 9 gallons) and got 4.5 gallons first runnings at 1.051. NOT happy with that. Sparged with 5 gallons to get target preboil volume (90 minute boil) of 9.5 gallons, sparge came out at 1.032. Preboil wound up at 1.040 for what is supposed to be a bigger beer.

So my question is (and yes I'm too lazy to google it), did my higher strike water volume screw my efficiency? And why? I know I've read somewhere that using too much water will mess with the gravity, I just want to know why. I'm planning a SMaSH for next weekend with some brand new very expensive hops and don't want to mess it up. Thanks for any help.

and your mill gap is??

 

[Beerwildered]

Math is confusing to many folks, but it is very helpful to understanding how variables affect process outcomes.

In general efficiency is how much you got compared to the maximum available. Efficiency is usually expressed as a percentage defined by: 100% * Actual Obtained / Max Available.

In brewing, efficiencies are about how much of the avialable extract (sugar) you collect vs. how much could be obtained from the grain (if you could get it all.) Volume only comes into play since we can’t directly measure the amount (mass or weight) of extract in wort - we can only measure the volume of wort, and its SG, and use that to calculate the amount of extract.

There are several efficiency measurements of interest in brewing:

• Mash Efficiency = Amount of Extract in BK / Max Potential Extract in Grain
• Mash Efficiency = Conversion Efficiency * Lauter Efficiency
• Conversion Efficiency = Amount of Extract Created in Mash / Max Potential Extract in Grain
• Lauter Efficiency = Amount of Extract in BK / Amount of Extract Created in Mash
• Transfer Efficiency = Amount of Extract in Fermenter / Amount of Extract in BK
• Brewhouse Efficiency = Mash Efficiency * Transfer Efficiency
• Brewhouse Efficiency = Amount of Extract in Fermenter/ Max Potential Extract in Grain

Note that none of the efficiency definitions involve volume, only the amount (mass or weight) of extract. It is possible to calculate the amount of extract if we know the volume of wort and its SG, however we can use a simpler approximation of amount of extract known as Points. One point will raise the SG of one gallon of wort by 0.001. Thus the number of points in one gallon of wort is:

Points / Gallon = 1000 * (SG - 1)​

Rather than doing the math, pts/gal is just taken as the three digits after the decimal point in the SG, and dropping any leading zeros. Thus wort with an SG of 1.037 has 37 pts/gal. You calaculate the total number of points in a volume of wort as: gal of wort * pts/gal, so 5 gal of wort with an SG of 1.037 has 5 gal * 37 pts/gal = 185 points.

We can also express the potential extract in grain in terms of points. Base malts usually contain about 37 points/lb of grain (commonly called points per pound per gallon or “ppg.”) This means that if 1 gal of wort is made with all of the possible extract from one pound of grain, then the wort would have an SG of 1.037. In grain databases, the extract potential is often given in SG rather than ppg, so the potential of a grain with 37 ppg would be listed as 1.037. Note that if you put all of the extract from 1 lb grain with a potential of 1.037 into 1 gal of water, you will have more than one gal of wort (since the extract has volume that adds to the total volume of wort), and the SG of the wort will be less than 1.037. This is a common point of confusion, which often leads to errors in calculating conversion efficiency.

We can use points to calculate efficiency. First we have to determine the number of potential points we start with in our grain bill. To do this we multiply the weight of each grain by the ppg of that grain, and add up the points for each grain. So, if we have 5 lb of grain with a potential of 1.037, and 5 lb with a potential of 1.035, then the total potetial points are 5 lb * 37 ppg + 5 lb * 35 ppg = 185 pts + 175 pts = 360 pts total extract potential. If we mash and sparge that 10 lb of grain with a total of 7.7 gal of water, and collect 6.5 gal of pre-boil wort at an SG of 1.045 then the number of points in our BK will be: 6.5 gal * 45 pts/gal = 292.5 pts. Using the equation for mash efficiency above, our mash efficiency will be: 292.5 pts / 360 pts = .8125 => ~81%.

If we boil that 6.5 gal of wort down to 5.5 gal, we will still have 292.5 pts of extract, since we only evaporate water during the boil, but no extract. The post boil wort will then have: 292.5 / 5.5 gal = 53.18 pts/gal => SG of ~1.053.

If we transfer 5.0 gal of the post-boil wort to the fermenter, then the fermenter will contain: 5.0 gal * 53 pts/gal = 265 points. Brewhouse efficiency then equals: 265 pts / 360 pts = 0.736 => 73.6%.

Now if we had used more brewing water (strike + sparge = ~8.51 gal), and collected 7.3125 gal of wort at 1.040 SG, our BK points would still be: 7.3125 gal * 40 pts/gal = 292.5 pts, and our mash efficiency still would have been ~81%. However, using more brewing water generally improves lauter efficiency, and therefore mash efficiency, so the collected wort would more likely have have an SG of about 1.041, giving BK points of 7.3125 * 41 = ~300 pts, for a mash efficiency of 300 pts / 360 pts => ~83%.

Brew on

This is a whole area that I have always struggled to understand. Your explanation was so crystal clear that I feel confident that I’ll be able to calculate my efficiencies during my next brew. Thank you.

To do that, I figured I’d need a list of grains and their ppg - and I discovered this:

http://www.howtobrew.com/book/section-2/what-is-malted-grain/table-of-typical-malt-yields

Any other resources you use for this?