Is it possible I only boil off 2qt/hour?

[johnbrain]

I'm still new and dialing in my kettle into my software. I couldn't figure out why my SG was off compared to the recipe. So I changed the efficiency to match my pre-boil gravity, then kept changing my evaporation rate until my SG matched.

1.050 Pre-Boil
1.058 Starting Gravity

That worked out to 2qt/hour but that seems low doesn't it? I guess the numbers don't lie. I was using the default 3.2 qt/hr before that. This is a 20qt/12" aluminum kettle on a stove top with a turbo water "boiler." It's a decent rolling boil but not massively vigorous ala water or low volume starters etc.

Thoughts?

 

[Sudstud]

My old 7 gallon turkey fryer kettle only boiled off 2 quarts per hour, so yes, its possible. I found it hard to believe at first too, but this number was proven time and time again, don't sweat it.

I do keep my boil pretty low, just enough to circulate the water.

 

[johnbrain]

Thanks. Just starting to dial everything in so I can consistently recreate batches. For my stout I had previously done a mini-mash with extract 5 gallon. This time I did all grain 2.5 gallons. Bottled last night and I didn't quite hit my FG so I am a little disappointed. And the sample didn't quite taste like the first time, although I switched from 2 row to Maris Otter so maybe that's why. And it's all grain. It tasted grainer actually. We'll see how it is in 6 weeks.

 

[Bradinator]

My system is the complete opposite as it seems to boil off over 1.5 gallons/hour. I wonder if elevation plays a factor? We are pretty high up, something like 1000m above sea level.

 

[billl]

"My system is the complete opposite as it seems to boil off over 1.5 gallons/hour. I wonder if elevation plays a factor? We are pretty high up, something like 1000m above sea level."

Not really. I'm close to sea level, but generally boil off 1.5+ gal/hr. It's mostly about how much heat your burner can get into the wort. Converting liquid to gas takes a lot of energy. If your burner isn't pumping out much heat, you don't covert much water to steam.

 

[KeyWestBrewing]

the sample didn't quite taste like the first time, although I switched from 2 row to Maris Otter so maybe that's why. And it's all grain. It tasted grainer actually.

Marris Otter is more biscuity and maltier, or "grainer" as you put it, than 2 Row. Thats probably it.

 

[johnbrain]

Marris Otter is more biscuity and maltier, or "grainer" as you put it, than 2 Row. Thats probably it.

Maybe I'll brew the exact same recipe with the 2 row ands see which I prefer. Hope this batch turns out good though. I want to have a tasting party. I think my tripel will brew on the mark. Bottling a red this weekend. Who knows what that will taste like.

 

[tre9er]

Pot diameter and boil ferocity are two huge contributors to boiloff. I would imagine humidity has something to do with it too??

 

[KeyWestBrewing]

Pot diameter and boil ferocity are two huge contributors to boiloff. I would imagine humidity has something to do with it too??

Definitely. The humidity down here is like 80% and I have a ton of boil off.

 

[stvcoburn]

Pot diameter and boil ferocity are two huge contributors to boiloff. I would imagine humidity has something to do with it too??

Agreed. Surface area is the largest factor to the evaporation. I'm certain that humidity effects evaporation rate as well.