texasbrewer73
Well-Known Member
I’ve seen a number of threads with brewers asking how they can improve their mashing efficiency so I thought I’d create a thread with some things to consider when trying to improve your efficiency.
To start, I sometimes interpret people thinking efficiency relates to the quality of their beer. This is not the case. Efficiency refers to how much fermentable sugar you are getting from your grains as compared to what the maximum possible yield is (theoretically). I am of the opinion that people shouldn’t worry about aiming for efficiencies higher than 80%. The savings you would see at the scale of a homebrewer are miniscule. High efficiencies are great for breweries where it can be very cost effective to get every bit of sugar out of their grains.
Ultimately, efficiency is a personal preference. Some are happy with 55-60% and others get >80% and want to gain another couple of points. It’s all up to you. If you are happy with your results, keep doing what you’re doing and don’t feel like you have to achieve a higher efficiency just because others are attaining those levels. One final general note – efficiency is also a factor on how to adjust your grain bill. If you are using a recipe, people generally include what efficiency the recipe is designed to produce the results. It’s important to adjust your grain bill accordingly to achieve the same results as the recipe intended.
Calculation
How you calculate your efficiency is more important than any of the steps following. For measuring efficiency, you must use your pre-boil gravity reading (starting gravity) and compare that to what your maximum yield could be. I’ve read where people with high efficiencies are calculating their gravity with their post boil wort (original gravity). It's pretty easy to gain efficiency points that way, but it's inaccurate. Original gravity and final gravity are used for calculating the ABV. With your starting gravity, there are a number of websites that have calculators whereby you enter grain bill and then your starting gravity. So long as the method has each of your specific grains, most seem pretty reliable. Make sure your volume measurements correct. Make sure you read your hydrometer or refractometer correctly. Ensure you measuring devices are calibrated. Take good measurements. No matter what you do to improve your efficiency, it's only as good as the measurements you take.
Equipment
Mashtun equipment can play a large factor into your efficiency. Using too large of a mashtun will result in a shorter grain bed. Shorter grain bed will reduce your efficiency. If using a cooler, consider getting a smaller cooler. If you do different size batches (i.e. sometimes 5 gal, sometimes 10), considering getting a second smaller cooler for your smaller batches. Also, fly sparging is far more difficult in a rectangular cooler than a round cooler because the grain bed will not rinse as evenly. Your filtering mechanism plays a smaller role as well. If you are using a manifold filter, consider changing up your design. Perhaps what seems like a good design may create dead spots and does not allow wort to move through the grain bed efficiently. If you are using a braided hose, how do you have it in your mash tun? When lautering, wort is looking for the path of least resistance to get out. A coiled up braided hose doesn’t offer much area space that really provides for a good lauter. John Palmer does a great job of explaining the problems with some designs in his “How to Brew” book. Read it. Know it.
Process
I’m a big believer that process is the biggest factor in gaining efficiency, sans an incredibly poor grain crush. There are more variables involved with your process than equipment or grain crush combined.
Mashing
Stirring at the beginning and end of a mash is essential. In the beginning, it distributes the water evenly through the grain and prevents so-called dough balls from forming. At the end of the mash it allows for the grains and water to be agitated one last time. In between, the length and frequency of stirring varies from one person to the next. Choose the method that gives you the best results. Stir more frequently if you are only stirring once or twice during a mash. If you can stir less frequently and still achieve the same numbers, then do so and keep the heat in your mash tun. If you are doing a recirculation mash, look for channeling – some areas may not be re-circulating as well as others. Also, I’ve seen a number of ways to bring the wort back into your tun. Some have a tube going into the mash. I’ve seen manifolds that distribute the mash akin to a sparge arm. I’ve seen some that re-purpose the sparge arm for this. Re-circulating at a fast rate can cause the mash to only run through a portion of your mash. The manifold/sparge arm work best for me and yields a more consistent recirculation.
Sparging
Without debating the merits of batch sparging vs. fly sparging, suffice to say that both methods have their advantages and disadvantages. Whichever method you choose, remember that the point of sparging is to rinse the grain bed. If fly sparging, maintain a consistent level of water above the grain bed – this keeps the water moving through the grain bed at a consistent rate. As mentioned above, fly sparging isn’t a good method for rectangular coolers. If you are using a rectangular cooler and want to keep it, consider batch sparging instead. If batch sparging, keep an eye out for channeling. That’s a good indicator some grains aren’t getting rinsed as well as others. Additionally, make sure that your sparge water volume calculations are correct. If you are sparging too much water, you’re leaving sugar behind.
Mashout
Some will say that mashing out serves no merit anymore to the home brewer. Some swear by it. For me, I swear by it. Aside from what it does to the quality of your wort by ending the enzymatic functions, a mashout infusion provides more liquid to your mash to help capture the sugars with stirring (at least for non-direct fired mash tuns and non-decoction mashing). Additionally, raising the temperature of the mash will increase the solubility of sugars.
Lautering
From my experience, lauter rate is the single most effective way to increase or decrease efficiency in your system. Too slow, and the wort isn’t moving through the grain bed fast enough to effectively rinse the grain (not to mention is gives plenty of time for tannin extraction). Too fast and the wort doesn’t have a chance to be in contact with the grain long enough. You will also increase your chance of channeling. While there is no single rate that works for everyone with every type of setup, I’ve found that a general rule of thumb is about a quart a minute to a minute 20 seconds (15-20 seconds per cup). This can vary depending on your eqpt and your recipe. Though some say a slow lauter will always be better, I believe there is a point of diminishing returns.
Grain Crush
The second single most effective way to enhance your efficiency is with your grain crush. It’s hard to just compare a picture online of one’s grain crush and say “Yep – looks good to me”. Assuming all other things in your brew system are dialed in and have been honed to your liking (and your beer’s liking), a low efficiency could simply be your crush. Whether you buy a mill and crush your own grain or buy from a retailer already crushed, look at your grain. There should be very few grains still intact (not to be confused with grain husks). If that is not the case, run the grain through the mill a second time. If you are using your own grain mill, dial in the rollers a notch and run the grain through again. I think of the grain as balance – most should be decent sized chunks of a piece of grain in sizes roughly ½ to 1/3 the size of a whole kernel. There will be some flour and there will be a few uncrushed grains. Too much uncrushed, mill again. Too much flour, add rice hulls and carry on.
Mash pH and Water
This isn’t terribly common, but if your mash pH ranges swing too high or low, this too can affect your efficiency. Without getting into water chemistry too much, do what’s needed to be done to get your water in the mid 5’s (I aim for 5.4 and monitor it if I’m not familiar with the recipe or it’s something that I’m just unsure of the calculated results). Also, pay attention to your water source's Calcium (Ca) levels. Proper levels promote enzyme activity and liveliness, thus contributing to greater conversion. Shoot for Ca levels around 100 ppm.
Conclusion
This is meant to be a guideline to look at the many things that will help you get more fermentable sugar from your grain. It’s by no means all encompassing and is intended to be at the macro level. There are a number of reasons why efficiencies can be low. The main thing is to measure well, try different techniques and, if your budget allows, try different equipment. As I said before, efficiency isn’t something we should try to obtain the highest amount of. Your results should just be to your liking. At the end of it all, you’ll still be making beer. And that’s a good thing.
To start, I sometimes interpret people thinking efficiency relates to the quality of their beer. This is not the case. Efficiency refers to how much fermentable sugar you are getting from your grains as compared to what the maximum possible yield is (theoretically). I am of the opinion that people shouldn’t worry about aiming for efficiencies higher than 80%. The savings you would see at the scale of a homebrewer are miniscule. High efficiencies are great for breweries where it can be very cost effective to get every bit of sugar out of their grains.
Ultimately, efficiency is a personal preference. Some are happy with 55-60% and others get >80% and want to gain another couple of points. It’s all up to you. If you are happy with your results, keep doing what you’re doing and don’t feel like you have to achieve a higher efficiency just because others are attaining those levels. One final general note – efficiency is also a factor on how to adjust your grain bill. If you are using a recipe, people generally include what efficiency the recipe is designed to produce the results. It’s important to adjust your grain bill accordingly to achieve the same results as the recipe intended.
Calculation
How you calculate your efficiency is more important than any of the steps following. For measuring efficiency, you must use your pre-boil gravity reading (starting gravity) and compare that to what your maximum yield could be. I’ve read where people with high efficiencies are calculating their gravity with their post boil wort (original gravity). It's pretty easy to gain efficiency points that way, but it's inaccurate. Original gravity and final gravity are used for calculating the ABV. With your starting gravity, there are a number of websites that have calculators whereby you enter grain bill and then your starting gravity. So long as the method has each of your specific grains, most seem pretty reliable. Make sure your volume measurements correct. Make sure you read your hydrometer or refractometer correctly. Ensure you measuring devices are calibrated. Take good measurements. No matter what you do to improve your efficiency, it's only as good as the measurements you take.
Equipment
Mashtun equipment can play a large factor into your efficiency. Using too large of a mashtun will result in a shorter grain bed. Shorter grain bed will reduce your efficiency. If using a cooler, consider getting a smaller cooler. If you do different size batches (i.e. sometimes 5 gal, sometimes 10), considering getting a second smaller cooler for your smaller batches. Also, fly sparging is far more difficult in a rectangular cooler than a round cooler because the grain bed will not rinse as evenly. Your filtering mechanism plays a smaller role as well. If you are using a manifold filter, consider changing up your design. Perhaps what seems like a good design may create dead spots and does not allow wort to move through the grain bed efficiently. If you are using a braided hose, how do you have it in your mash tun? When lautering, wort is looking for the path of least resistance to get out. A coiled up braided hose doesn’t offer much area space that really provides for a good lauter. John Palmer does a great job of explaining the problems with some designs in his “How to Brew” book. Read it. Know it.
Process
I’m a big believer that process is the biggest factor in gaining efficiency, sans an incredibly poor grain crush. There are more variables involved with your process than equipment or grain crush combined.
Mashing
Stirring at the beginning and end of a mash is essential. In the beginning, it distributes the water evenly through the grain and prevents so-called dough balls from forming. At the end of the mash it allows for the grains and water to be agitated one last time. In between, the length and frequency of stirring varies from one person to the next. Choose the method that gives you the best results. Stir more frequently if you are only stirring once or twice during a mash. If you can stir less frequently and still achieve the same numbers, then do so and keep the heat in your mash tun. If you are doing a recirculation mash, look for channeling – some areas may not be re-circulating as well as others. Also, I’ve seen a number of ways to bring the wort back into your tun. Some have a tube going into the mash. I’ve seen manifolds that distribute the mash akin to a sparge arm. I’ve seen some that re-purpose the sparge arm for this. Re-circulating at a fast rate can cause the mash to only run through a portion of your mash. The manifold/sparge arm work best for me and yields a more consistent recirculation.
Sparging
Without debating the merits of batch sparging vs. fly sparging, suffice to say that both methods have their advantages and disadvantages. Whichever method you choose, remember that the point of sparging is to rinse the grain bed. If fly sparging, maintain a consistent level of water above the grain bed – this keeps the water moving through the grain bed at a consistent rate. As mentioned above, fly sparging isn’t a good method for rectangular coolers. If you are using a rectangular cooler and want to keep it, consider batch sparging instead. If batch sparging, keep an eye out for channeling. That’s a good indicator some grains aren’t getting rinsed as well as others. Additionally, make sure that your sparge water volume calculations are correct. If you are sparging too much water, you’re leaving sugar behind.
Mashout
Some will say that mashing out serves no merit anymore to the home brewer. Some swear by it. For me, I swear by it. Aside from what it does to the quality of your wort by ending the enzymatic functions, a mashout infusion provides more liquid to your mash to help capture the sugars with stirring (at least for non-direct fired mash tuns and non-decoction mashing). Additionally, raising the temperature of the mash will increase the solubility of sugars.
Lautering
From my experience, lauter rate is the single most effective way to increase or decrease efficiency in your system. Too slow, and the wort isn’t moving through the grain bed fast enough to effectively rinse the grain (not to mention is gives plenty of time for tannin extraction). Too fast and the wort doesn’t have a chance to be in contact with the grain long enough. You will also increase your chance of channeling. While there is no single rate that works for everyone with every type of setup, I’ve found that a general rule of thumb is about a quart a minute to a minute 20 seconds (15-20 seconds per cup). This can vary depending on your eqpt and your recipe. Though some say a slow lauter will always be better, I believe there is a point of diminishing returns.
Grain Crush
The second single most effective way to enhance your efficiency is with your grain crush. It’s hard to just compare a picture online of one’s grain crush and say “Yep – looks good to me”. Assuming all other things in your brew system are dialed in and have been honed to your liking (and your beer’s liking), a low efficiency could simply be your crush. Whether you buy a mill and crush your own grain or buy from a retailer already crushed, look at your grain. There should be very few grains still intact (not to be confused with grain husks). If that is not the case, run the grain through the mill a second time. If you are using your own grain mill, dial in the rollers a notch and run the grain through again. I think of the grain as balance – most should be decent sized chunks of a piece of grain in sizes roughly ½ to 1/3 the size of a whole kernel. There will be some flour and there will be a few uncrushed grains. Too much uncrushed, mill again. Too much flour, add rice hulls and carry on.
Mash pH and Water
This isn’t terribly common, but if your mash pH ranges swing too high or low, this too can affect your efficiency. Without getting into water chemistry too much, do what’s needed to be done to get your water in the mid 5’s (I aim for 5.4 and monitor it if I’m not familiar with the recipe or it’s something that I’m just unsure of the calculated results). Also, pay attention to your water source's Calcium (Ca) levels. Proper levels promote enzyme activity and liveliness, thus contributing to greater conversion. Shoot for Ca levels around 100 ppm.
Conclusion
This is meant to be a guideline to look at the many things that will help you get more fermentable sugar from your grain. It’s by no means all encompassing and is intended to be at the macro level. There are a number of reasons why efficiencies can be low. The main thing is to measure well, try different techniques and, if your budget allows, try different equipment. As I said before, efficiency isn’t something we should try to obtain the highest amount of. Your results should just be to your liking. At the end of it all, you’ll still be making beer. And that’s a good thing.
