Mofo
Grandmaster Brewer
I just googled “missed my original gravity” and got 1,830,000 hits. Here’s number 1,830,001.
I recently did my tenth brew. It was my 6th all-grain brew. I’ve managed to hit or come within a point or two of estimated OG on each. But this last brew, I was not only off, I was off by 14 points!
The recipe was Henrik’s Imperial Amber, from the BS cloud. It has an estimated OG of 1.088 and is the biggest beer I’ve attempted. I rejiggered the recipe so that my brew kit would produce the same estimated OG, IBUs, EBC and ABV. This mostly meant adding a lot more base malt than the original recipe called for, to account for my efficiency. I mash with a 38 liter (10 gal) Gott-style cooler and boil in a 33 liter (9 gal) kettle.
The rejiggering was done with BS2, but I plugged all my brew day numbers into a spreadsheet I’ve been building since I started all-grain (i.e. not long ago). I attach that spreadsheet reluctantly because it feels like going out in public in my underwear.
Measuring for volume, SG and now pH has been beneficial, but I need the help of the brew gurus here to analyze data and hopefully see where things went south. I understand that it’s likely not a single thing that went wrong, but a combination of things. Analyzing numbers has taught me a few things (I think!) and left me with more than a few questions. For anyone willing to wade into my spreadsheet, my immense appreciation awaits. Warning: I’m an American metrics convert.
Spreadsheet Key:
• Basic brew info is across the top
• Right-hand side is most of the info you’d find in the BS Equipment Profile. Figures in black are averages, green and blue are for this brew.
• Color-coded sections follow the process: Water, Mash, Boil, and Ferment (Bottling and Tasting Notes to be added)
• Colored arrows “⌦” at the center of each section toggle between a chart view and the actual worksheet where I plugged in numbers.
As for what I learned and what I still don’t get…
The big discovery I made (again, I think!) is that I lost 5 points in my mash and another 9 points in the boil. Or maybe I’m conflating the data: The estimated pre-boil gravity was 1.069. Mine was 1.064. Then for the boil I was supposed to go from 69 to 88 (19 points), but instead went from 64 to 74 (10 points). A difference of 9 points. Am I misunderstanding this?
As for what went wrong in the mash, my best guess is that I didn’t use pH 5.2 stabilizer and needed to with a big beer like this. My strike water pH measured 6.6 but when I drained the tun 45 minutes later it was 5.0. (I know now that I should just “fire and forget” with pH 5.2 and/or take a pH measure sooner in the mash.) Another guess is that I didn’t uncap and stir the mash. I maintained a steady, perfect temp throughout the 45 minute rest, but maybe I had pockets I should have stirred out. I don’t think the problem was my crush, because I used the same mill I’ve used in all previous brews, when I’ve hit my numbers. Or maybe the problem is just that I can’t mash an 80+ beer in a 10-gallon Gott while my mash efficiency is 73%.
As for the boil, I’m clueless. My mid-boil SG was 1.065, only a single point higher than my pre-boil gravity! I had backed off the flame very slightly for this brew but my evaporation rate was nearly the same as it’s been in previous brews. I know now that I should have used the Boil Off tool as soon as I had my new pre-boil gravity. But I did use it at mid-boil and and decided to go 30 minutes past my original 90-minute boil. Still, it gained me only 2 points. The thing is, in order to have gone from 69 to 88 inside a 90-minute boil, my evaporation rate would have to be 16%.
[Edit: I’ve just looked back at the original Henrik’s Imperial Amber recipe and see that their boil volume is nearly 2 liters less than my 30-liter boil volume, though its post-boil volume is nearly the same at 25.15 liters. But according to the Boil Off tool, to finish the boil with 25 liters of wort that had a starting gravity of 1.069, you’d need an evaporation rate of only 5%. And that gets you a finished wort with an OG of only 1.078! So I’m even more confused. How did they ever get to 1.088!?]
Lastly, if you're tired of answering people’s “missed OG” questions, but fancy yourself a spreadsheet king, I’d really appreciate suggestions on how I could improve mine. It’s a work in progress and there’s a lot to add, including some obvious calculators, but it’s far enough along to see the general direction I’m taking it. I didn't know how to make a chart when I started it. Like brewing, there's a lot more to learn here, too. As I said, I feel like I'm only in skivvies; toss a man some trousers!
And if you don’t have input on either front, I still appreciate your having read this far. Thanks for the moral support!
And cheers!
I recently did my tenth brew. It was my 6th all-grain brew. I’ve managed to hit or come within a point or two of estimated OG on each. But this last brew, I was not only off, I was off by 14 points!
The recipe was Henrik’s Imperial Amber, from the BS cloud. It has an estimated OG of 1.088 and is the biggest beer I’ve attempted. I rejiggered the recipe so that my brew kit would produce the same estimated OG, IBUs, EBC and ABV. This mostly meant adding a lot more base malt than the original recipe called for, to account for my efficiency. I mash with a 38 liter (10 gal) Gott-style cooler and boil in a 33 liter (9 gal) kettle.
The rejiggering was done with BS2, but I plugged all my brew day numbers into a spreadsheet I’ve been building since I started all-grain (i.e. not long ago). I attach that spreadsheet reluctantly because it feels like going out in public in my underwear.
Measuring for volume, SG and now pH has been beneficial, but I need the help of the brew gurus here to analyze data and hopefully see where things went south. I understand that it’s likely not a single thing that went wrong, but a combination of things. Analyzing numbers has taught me a few things (I think!) and left me with more than a few questions. For anyone willing to wade into my spreadsheet, my immense appreciation awaits. Warning: I’m an American metrics convert.
Spreadsheet Key:
• Basic brew info is across the top
• Right-hand side is most of the info you’d find in the BS Equipment Profile. Figures in black are averages, green and blue are for this brew.
• Color-coded sections follow the process: Water, Mash, Boil, and Ferment (Bottling and Tasting Notes to be added)
• Colored arrows “⌦” at the center of each section toggle between a chart view and the actual worksheet where I plugged in numbers.
As for what I learned and what I still don’t get…
The big discovery I made (again, I think!) is that I lost 5 points in my mash and another 9 points in the boil. Or maybe I’m conflating the data: The estimated pre-boil gravity was 1.069. Mine was 1.064. Then for the boil I was supposed to go from 69 to 88 (19 points), but instead went from 64 to 74 (10 points). A difference of 9 points. Am I misunderstanding this?
As for what went wrong in the mash, my best guess is that I didn’t use pH 5.2 stabilizer and needed to with a big beer like this. My strike water pH measured 6.6 but when I drained the tun 45 minutes later it was 5.0. (I know now that I should just “fire and forget” with pH 5.2 and/or take a pH measure sooner in the mash.) Another guess is that I didn’t uncap and stir the mash. I maintained a steady, perfect temp throughout the 45 minute rest, but maybe I had pockets I should have stirred out. I don’t think the problem was my crush, because I used the same mill I’ve used in all previous brews, when I’ve hit my numbers. Or maybe the problem is just that I can’t mash an 80+ beer in a 10-gallon Gott while my mash efficiency is 73%.
As for the boil, I’m clueless. My mid-boil SG was 1.065, only a single point higher than my pre-boil gravity! I had backed off the flame very slightly for this brew but my evaporation rate was nearly the same as it’s been in previous brews. I know now that I should have used the Boil Off tool as soon as I had my new pre-boil gravity. But I did use it at mid-boil and and decided to go 30 minutes past my original 90-minute boil. Still, it gained me only 2 points. The thing is, in order to have gone from 69 to 88 inside a 90-minute boil, my evaporation rate would have to be 16%.
[Edit: I’ve just looked back at the original Henrik’s Imperial Amber recipe and see that their boil volume is nearly 2 liters less than my 30-liter boil volume, though its post-boil volume is nearly the same at 25.15 liters. But according to the Boil Off tool, to finish the boil with 25 liters of wort that had a starting gravity of 1.069, you’d need an evaporation rate of only 5%. And that gets you a finished wort with an OG of only 1.078! So I’m even more confused. How did they ever get to 1.088!?]
Lastly, if you're tired of answering people’s “missed OG” questions, but fancy yourself a spreadsheet king, I’d really appreciate suggestions on how I could improve mine. It’s a work in progress and there’s a lot to add, including some obvious calculators, but it’s far enough along to see the general direction I’m taking it. I didn't know how to make a chart when I started it. Like brewing, there's a lot more to learn here, too. As I said, I feel like I'm only in skivvies; toss a man some trousers!
And if you don’t have input on either front, I still appreciate your having read this far. Thanks for the moral support!
And cheers!