Unusally high boil off

[Dark_Brew]

I've been experiencing high boil off rates. Yesterday I brewed and it appears I lost about 3 gallons of water to boil off. Here was the recipe and the process.

4# marris otter
3# 2-row
.75# carapils
.5# crystal 10
.5# vienna
.5oz cascade 60min
.25oz cascade 45min
.25oz cascade 15min
.25oz cascade 5min

I use 10gallon rubbermaid cooler for my mash tun. I doughed in with 3 gallons of water and mashed at 152* for 60 min. I then sparged with 5.5 gallons of water, collecting approx 7gallons to start my boil.

After a 60min boil, I chilled my wort with an immersion chiller. When I racked the wort into my fermenter I had just a hair over 4gallons.

I brewed in the afternoon outside with a propane burner and 62qt stainless stockpot. It was about 88* with 40 - 50% humidity.

My question is what are somethings I can do to reduce this amount of boil off. It was not a very vigorous boil. I could try reducing the gas a little. I've thought about cutting a 6 or 8" hole in my lid and boiling with the lid on. Any thoughts or ideas would be great.


FWIW, I haven't posted here much, but I read these forums frequently and have used your collective knowledge to improve my brewing all the way around. Thanks

 

[JBrady]

If I were in you position I would just increase my pre boil volume and do a hard boil. I wouldn't weaken the boil to try to adjust post boil volumes, then you risk a weaker hop utilization. I usually boil off 1.5 gallons with my 10 gallon pot and propane burner. I don't understand why your boiling off so much with a similar setup. Just increase your pre boil and keep on truckin!

 

[JBrady]

Also don't boil with the lid on, you need to let the DMS evaporate out of the boil pot.

Do you use leaf hops or pellet hops? If you use leaf hops then some of that lost volume could be soaked up in your hops.

 

[magnj]

I boiled off nearly 4 gallons on my last brew. 10 gallon batches, 15 gallon 17" diameter kettles. Good boil but not insane. Looking for insight as well.

 

[Dark_Brew]

I use pellet hops. My pot has a 15.5" opening, I figured if I cut an 8" hole in the lid, it would still allow for evaporation, just not as much. I don't want to sparge with too much water, so I will probably just add an extra gallon or two directly to my boil pot.

 

[Dark_Brew]

It has to have something to do with my burner setup. There are 3 other guys in my neighborhood who brew, and I was discussing this issue a few weeks ago with one of them. He has the exact opposite problem, he is always having to extend his boils to boil off enough water.

 

[JBrady]

so I will probably just add an extra gallon or two directly to my boil pot.

This will work fine and solve your problem until you find out what your real issue may be.

 

[Maxkling]

How many batches do you get to a tank of propane?

 

[Dark_Brew]

usually 3-4. More like 3 and I change the tank on the 4th. I use the burner to heat strike water, sparge water and boil.

EDIT: These are also just exchange tanks, I think you get shorted a little doing it that way instead of having your own tank refilled.

 

[Maxkling]

Yea from what I've seen, depending on the burner, size of batch, time of boil, you should get at least 4 batches to a tank. I was just making sure it wasn't like 1.