EarlyAmateurZymurgist
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- Aug 4, 2013
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I brewed my first all-grain batch of beer over twenty years ago. Something that I learned fairly quickly was that mash and lauter tun design made a huge difference in the outcome of a mash. For those who have yet to make an investment in all-grain gear, I recommend single-infusion mashing with a cooler-based combined mash/lauter tun with a proper false bottom, as it simplifies the process.
With that said, cooler geometry makes a difference. Professional brew house mash tuns are round for a reason; namely, it promotes equal hydrostatic pressure across the grain bed. Back in the Gott days, there wasn't a huge difference between Rubbermaid and Igloo coolers, as both manufacturers built their coolers to industrial standards. However, Rubbermaid appears to have progressively cheapened the build quality of their beverage coolers over the last twenty years to in order to meet big-box store price points. Igloo has also done the same with their big-box store coolers. However, Igloo's industrial yellow and red coolers are a different story. The industrial coolers handle boiling water much better than the big-box coolers. They also hold temperature better than the big box coolers. They will hold a mash to within a degree or two of the strike temperature for an hour or more. Zoro Tools (the retail arm of Grainger) is one of the best places that I have found to order yellow industrial Igloo coolers. They offer free shipping on orders above $50.00 and one can usually find a coupon that will cover the cost of shipping for orders under $50.00.
False bottom design makes a huge difference in extract efficiency and quality. A lot of people will attempt to convince you to build a slotted manifold or a tubular mesh based mash strainer. Ignore these brewers. A quick examination of any professional craft brewery will reveal that their lauter tuns have proper false bottoms. A properly designed false bottom makes lautering a joy. In my humble opinion, the nicest off-the-shelf false bottom that is currently available for beverage coolers is the 16% open space slotted stainless steel false bottom that Adventures in Homebrewing sells. It's a work of art. This false bottom can be setup for soft-plumbed (silicone tubing connected) configuration between the false bottom and the ball valve by using a hose barb on the inside of the ball valve assembly and ordering a stainless 1/2” MPT to 3/8” hose barb ninety degree elbow fitting (item number 73-4109) and two stainless locks nuts with the false bottom.
Finally, let's get to one of the most highly contentious subjects within the amateur brewing community; namely, sparging. Truth be told, I am not a fan of multiple lautering (a.k.a. "batch sparging"), as it tends to produce much dirtier "runnings" than traditional continuous sparging (a.k.a. "fly sparging"). Cleaner runoff means cleaner, smoother tasting beer that needs less aging to reach maturity. Continuous sparging will also produce more extract than multiple lautering for any given crush. The rollers on my non-adjustable Schmidling Malt Mill have a 0.045" gap, which is considered to be too wide on this forum. However, my average combined grist extraction rate with domestic malt is 30 points per pound per gallon with domestic malt and 32 points per pound per gallon with imported malt. If we treat all of the malt in my grists as base malt, then my extraction efficiencies are:
30 / 36 x 100 = 83.3%
32 / 36 x 100 = 88.9%
Now, if we were to take into account that 10-20% of my grists are usually specialty malts, then my weighted extraction efficiencies are actually higher than the values shown above. These efficiencies are difficult to duplicate using other sparging methods with malt that has been milled to the same level of granularity.
I tend to prefer to use points per pound per gallon extraction rates instead of weighted mash efficiencies because they allow me to establish brew house metrics that can be used to formulate recipes without having to resort to using software. I do not dislike computers or computer software. I hold undergraduate and advanced degrees in computer science and have worked as a computer scientist and engineer for over thirty years. However, I do not want to have to interface with a whirling deterministic finite automaton on brew day. I want to be able to rectify brew house problems on the fly in my head; therefore, I work with points per pound per gallon.
Here's a strategy for incorporating points per pound per gallon into one's brew house:
First, one needs to calculate the points per pound per gallon extraction rates for one’s brew house.
points_per_pound_per_gallon = (batch_original_gravity - 1.0) x 1,000 x batch_volume_in_gallons / batch_grist_mass_in_pounds
In practice, the (batch_original_gravity - 1.0) x 1,000 portion of the equation can be simplified by taking the original gravity reading lopping off the "1" and converting the number to the right of the decimal point to a whole number (e.g., 1.056 becomes 56), as that's all this part of the equation accomplishes.
Using a 5.5-gallon batch of 1.056 wort that was made with 11 pounds of grist to put the equation into practice yields:
batch_original_gravity = 1.056
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 11
points_per_pound_per_gallon = (1.056 - 1.0) x 1,000 x 5.5 / 11 = 28
Now, if we perform this calculation for several batches, sum the points per pound per gallon values, and divide by the number of batches that were summed, we will arrive at our average brew house extraction rate in points per pound per gallon.
Example
Batch #1 = 26.5 points per pound per gallon
Batch #2 = 27 points per pound per gallon
Batch #3 = 30.5 points per pound per gallon
Batch #4 = 28 points per pound per gallon
Batch #5 = 29 points per pound per gallon
average_points_per_pound_per_gallon = 26.5 + 27 + 30.5 + 28 + 29 / 5 = 28.2
With experience, the variance in the points per pound per gallon values (the difference values) from batch to batch will narrow, and one will have a solid metric with which to use in recipe formulation.
Now that we have found our average brew house extraction rate, let's put it into practice using a hypothetical 11-gallon recipe that we would like to adjust for our 5.5 gallon brew house.
Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 11
batch_mass_in_pounds = 23
Grist Composition
British Pale Malt: 20.75 pounds
60L Crystal Malt: 2.25 pounds
Calculating the recipe points per pound per gallon extraction rate yields :
recipe_points_per_pound_per_gallon = (1.064 - 1.0) x 1,000 x 11 / 23 = 30.6
If we compare the recipe’s extraction rate to ours, we will clearly see that we cannot just cut the recipe in half; therefore, we need to scale the grist to fit our brew house extraction rate. We can handle scaling two different ways. The easiest and most logical way is to calculate the amount of grist that that we will need to hit the recipe’s O.G. in our brew house, and then divide this mass into malt percentages that are proportional to those found in the original recipes.
Calculating how many pounds of grist that we need to hit 1.064 yields:
batch_mass_in_pounds = (batch_original_gravity - 1.0) x 1,000 x batch_volume_in_gallons / average_points_per_pound_per_gallon
batch_grist_mass_in_pounds = (1.064 - 1.0) x 1,000 x 5.5 / 28.2 ~= 12.5lbs
With that calculation complete, we need to calculate grist percentages from the original recipe.
recipe_total_grist_mass = 23lbs
recipe_british_pale_ale_percentage = 20.75 / 23 x 100 ~= 90%
recipe_60L_crystal_percentage = 2.25 / 23 x 100 ~= 10%
With these numbers, we can now formulate our grist.
Our Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 12.5
British Pale Malt: 12.5 x 0.9 = 11.25lbs (11.25 is 90% of 12.5)
60L Crystal Malt: 12.5 x 0.1 = 1.25lbs (1.25 is 10% of 12.5)
The second way to adjust a recipe based on one’s brew house extraction rate is to calculate a grist scaling factor that takes into account the differences in brew house extraction rates and a batch volume divisor that takes into account the differences in batch volumes.
grist_scaling_factor = recipe_extraction_rate / our_average_extraction_rate
grist_scaling_factor = 30.6 / 28.2 ~= 1.085
batch_volume_divisor = recipe_batch_volume / our_batch_volume
batch_volume_divisor = 11 / 5.5 = 2
brew_house_extraction_rate_adjusted_malt_mass = malt_mass x grist_scaling_factor / batch_volume_divisor
Our Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 23 x 1.085 / 2 ~= 12.5
British Pale Malt: 20.75 x 1.085 x 0.5 ~= 11.25
60L Crystal Malt: 2.25 x 1.085 x 0.5 ~= 1.25
(note: the symbol “~=” denotes approximately equal to)
In closing, I know that much of what I have posted probably flew over the heads of many forum readers. However, most people can master this information with a little practice.
With that said, cooler geometry makes a difference. Professional brew house mash tuns are round for a reason; namely, it promotes equal hydrostatic pressure across the grain bed. Back in the Gott days, there wasn't a huge difference between Rubbermaid and Igloo coolers, as both manufacturers built their coolers to industrial standards. However, Rubbermaid appears to have progressively cheapened the build quality of their beverage coolers over the last twenty years to in order to meet big-box store price points. Igloo has also done the same with their big-box store coolers. However, Igloo's industrial yellow and red coolers are a different story. The industrial coolers handle boiling water much better than the big-box coolers. They also hold temperature better than the big box coolers. They will hold a mash to within a degree or two of the strike temperature for an hour or more. Zoro Tools (the retail arm of Grainger) is one of the best places that I have found to order yellow industrial Igloo coolers. They offer free shipping on orders above $50.00 and one can usually find a coupon that will cover the cost of shipping for orders under $50.00.
False bottom design makes a huge difference in extract efficiency and quality. A lot of people will attempt to convince you to build a slotted manifold or a tubular mesh based mash strainer. Ignore these brewers. A quick examination of any professional craft brewery will reveal that their lauter tuns have proper false bottoms. A properly designed false bottom makes lautering a joy. In my humble opinion, the nicest off-the-shelf false bottom that is currently available for beverage coolers is the 16% open space slotted stainless steel false bottom that Adventures in Homebrewing sells. It's a work of art. This false bottom can be setup for soft-plumbed (silicone tubing connected) configuration between the false bottom and the ball valve by using a hose barb on the inside of the ball valve assembly and ordering a stainless 1/2” MPT to 3/8” hose barb ninety degree elbow fitting (item number 73-4109) and two stainless locks nuts with the false bottom.
Finally, let's get to one of the most highly contentious subjects within the amateur brewing community; namely, sparging. Truth be told, I am not a fan of multiple lautering (a.k.a. "batch sparging"), as it tends to produce much dirtier "runnings" than traditional continuous sparging (a.k.a. "fly sparging"). Cleaner runoff means cleaner, smoother tasting beer that needs less aging to reach maturity. Continuous sparging will also produce more extract than multiple lautering for any given crush. The rollers on my non-adjustable Schmidling Malt Mill have a 0.045" gap, which is considered to be too wide on this forum. However, my average combined grist extraction rate with domestic malt is 30 points per pound per gallon with domestic malt and 32 points per pound per gallon with imported malt. If we treat all of the malt in my grists as base malt, then my extraction efficiencies are:
30 / 36 x 100 = 83.3%
32 / 36 x 100 = 88.9%
Now, if we were to take into account that 10-20% of my grists are usually specialty malts, then my weighted extraction efficiencies are actually higher than the values shown above. These efficiencies are difficult to duplicate using other sparging methods with malt that has been milled to the same level of granularity.
I tend to prefer to use points per pound per gallon extraction rates instead of weighted mash efficiencies because they allow me to establish brew house metrics that can be used to formulate recipes without having to resort to using software. I do not dislike computers or computer software. I hold undergraduate and advanced degrees in computer science and have worked as a computer scientist and engineer for over thirty years. However, I do not want to have to interface with a whirling deterministic finite automaton on brew day. I want to be able to rectify brew house problems on the fly in my head; therefore, I work with points per pound per gallon.
Here's a strategy for incorporating points per pound per gallon into one's brew house:
First, one needs to calculate the points per pound per gallon extraction rates for one’s brew house.
points_per_pound_per_gallon = (batch_original_gravity - 1.0) x 1,000 x batch_volume_in_gallons / batch_grist_mass_in_pounds
In practice, the (batch_original_gravity - 1.0) x 1,000 portion of the equation can be simplified by taking the original gravity reading lopping off the "1" and converting the number to the right of the decimal point to a whole number (e.g., 1.056 becomes 56), as that's all this part of the equation accomplishes.
Using a 5.5-gallon batch of 1.056 wort that was made with 11 pounds of grist to put the equation into practice yields:
batch_original_gravity = 1.056
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 11
points_per_pound_per_gallon = (1.056 - 1.0) x 1,000 x 5.5 / 11 = 28
Now, if we perform this calculation for several batches, sum the points per pound per gallon values, and divide by the number of batches that were summed, we will arrive at our average brew house extraction rate in points per pound per gallon.
Example
Batch #1 = 26.5 points per pound per gallon
Batch #2 = 27 points per pound per gallon
Batch #3 = 30.5 points per pound per gallon
Batch #4 = 28 points per pound per gallon
Batch #5 = 29 points per pound per gallon
average_points_per_pound_per_gallon = 26.5 + 27 + 30.5 + 28 + 29 / 5 = 28.2
With experience, the variance in the points per pound per gallon values (the difference values) from batch to batch will narrow, and one will have a solid metric with which to use in recipe formulation.
Now that we have found our average brew house extraction rate, let's put it into practice using a hypothetical 11-gallon recipe that we would like to adjust for our 5.5 gallon brew house.
Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 11
batch_mass_in_pounds = 23
Grist Composition
British Pale Malt: 20.75 pounds
60L Crystal Malt: 2.25 pounds
Calculating the recipe points per pound per gallon extraction rate yields :
recipe_points_per_pound_per_gallon = (1.064 - 1.0) x 1,000 x 11 / 23 = 30.6
If we compare the recipe’s extraction rate to ours, we will clearly see that we cannot just cut the recipe in half; therefore, we need to scale the grist to fit our brew house extraction rate. We can handle scaling two different ways. The easiest and most logical way is to calculate the amount of grist that that we will need to hit the recipe’s O.G. in our brew house, and then divide this mass into malt percentages that are proportional to those found in the original recipes.
Calculating how many pounds of grist that we need to hit 1.064 yields:
batch_mass_in_pounds = (batch_original_gravity - 1.0) x 1,000 x batch_volume_in_gallons / average_points_per_pound_per_gallon
batch_grist_mass_in_pounds = (1.064 - 1.0) x 1,000 x 5.5 / 28.2 ~= 12.5lbs
With that calculation complete, we need to calculate grist percentages from the original recipe.
recipe_total_grist_mass = 23lbs
recipe_british_pale_ale_percentage = 20.75 / 23 x 100 ~= 90%
recipe_60L_crystal_percentage = 2.25 / 23 x 100 ~= 10%
With these numbers, we can now formulate our grist.
Our Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 12.5
British Pale Malt: 12.5 x 0.9 = 11.25lbs (11.25 is 90% of 12.5)
60L Crystal Malt: 12.5 x 0.1 = 1.25lbs (1.25 is 10% of 12.5)
The second way to adjust a recipe based on one’s brew house extraction rate is to calculate a grist scaling factor that takes into account the differences in brew house extraction rates and a batch volume divisor that takes into account the differences in batch volumes.
grist_scaling_factor = recipe_extraction_rate / our_average_extraction_rate
grist_scaling_factor = 30.6 / 28.2 ~= 1.085
batch_volume_divisor = recipe_batch_volume / our_batch_volume
batch_volume_divisor = 11 / 5.5 = 2
brew_house_extraction_rate_adjusted_malt_mass = malt_mass x grist_scaling_factor / batch_volume_divisor
Our Simple Pale Ale
batch_original_gravity = 1.064
batch_volume_in_gallons = 5.5
batch_grist_mass_in_pounds = 23 x 1.085 / 2 ~= 12.5
British Pale Malt: 20.75 x 1.085 x 0.5 ~= 11.25
60L Crystal Malt: 2.25 x 1.085 x 0.5 ~= 1.25
(note: the symbol “~=” denotes approximately equal to)
In closing, I know that much of what I have posted probably flew over the heads of many forum readers. However, most people can master this information with a little practice.
