Boil Off Issue

[daveooph131]

I am 3 batches into all grain. First two batches nailed all my number perfectly including boil off.

This third attempt though I had a higher mash eff. then expected and I boiled off an additional .5 gallon in an hour.

What gives? I kept the burner and boil to a similar roll as the first two batches. The only thing I can think about is that it was much colder on the third batch outside. I noticed a lot more steam as result.

Does water evaporate quicker when boiling in a cold climate? This doesn't make sense to me, but man it's been bugging me so I thought I would post.

 

[Polboy]

it is humidity that affect your boil off and on cold days it tends to go down

 

[daveooph131]

it is humidity that affect your boil off and on cold days it tends to go down

See I thought the same too but it was the cold day where I booked off an extra half gallon. Very weird.

 

[Waterboy42]

I always have a higher boil off rate in the dryer winters. I usually leave an extra half gallon, or so, when I get to my 60 minute volume. I did a weekend of testing with boiling plain water in the winter to figure out relative boil off rates to approximate the amount of extra water is boiled off versus the spring/fall humidities.

 

[b-boy]

I think he meant that humidity goes down, so you would lose more to the boil off.

 

[daveooph131]

Oh I see boil off is less in high humidity and more in less humidity. This makes sense. In going to start checking humidity before i brew.

 

[Iqbal624]

Oh I see boil off is less in high humidity and more in less humidity. This makes sense. In going to start checking humidity before i brew.

Yay! Yet another thing to factor in!

I'm doing my first Biab this weekend and pre-boil volume still has me puzzled.

 

[lamppa]

IME the hardest things to figure out were
A) temperatures
B) volumes

it just takes trial and error on YOUR system, no one can give you a straight answer, only guidance and generalizations, because they have never used your system. Just get out there and brew, take good notes on temps and volumes. You'll figure it out.

 

[Dan]

I had the same question awhile back this thread addresses from a guy a lot smarter than me. https://www.homebrewtalk.com/f11/new-burner-trials-276754/

 

[Iqbal624]

I had the same question awhile back this thread addresses from a guy a lot smarter than me. https://www.homebrewtalk.com/f11/new-burner-trials-276754/

Thanks for that! I love people smarter than me. it makes things so much easier!