Boil Loss

[rstump]

A few weeks ago was doing a 5 gal boil for an American Wheat kit and at least partially because of a boil over I came up way low in the fermenter and had to top off with make-up water. Today in order to "dial in" the process for another batch, I put a measured 5 gal of cold water in the kettle and lit the fire. After one hour of serious boil, I let it cool and measred the remainer; 2 1/2 gal, 1 1/4 cups. Almost 2.5 gal loss in a 1 hour boil.... Dosn't this seem like a lot?

 

[KeyWestBrewing]

Damn thats pretty much half of what you started with. Thats way more than I usually boil off. For me its usually around a gallon. Are you sure you measured it correctly? Not trying to doubt you but that does seem like a lot of boil off.

 

[StrongBad42]

I just did a 90 minute boil yesterday and only lost maybe a gallon and a half. That does seem like a lot for 60 minutes.

 

[Bippar]

I use an electric stove for a 5 gal batch, using a 5 gal kettle. Boil off is ~ .60 gal/hr. Not a big boil....but the job gets done. Just tossing this out there for comparative purposes only.

 

[Schol-R-LEA]

While it is a lot, 2.5 gallons isn't wholly implausible, depending on your setup. What kind of heat source are you using? Do you know how many BTUs it puts out per hour? How long does it take to bring the whole 5 gal. to boil? If you are using a high-pressure propane burner, like some of the Bayou Classic models, you could easily get this sort of results.

There are two solutions I can suggest. First, dial down the heat somewhat; at full blast, you are just asking for a boil-over. Second, simply use more water to start with, and anticipate the rate of boil-down at the heating rate you decide to use.

This second part may require additional equipment; if you are currently using a 20qt boiler, I would recommend getting a boiler that is at least 30qts. in size (if not 40qts or more) to give you extra space both for heating additional water and for containing boil-ups long enough to bring the heat down in time to prevent it from boiling over. This will also help later if you move on to all-grain brewing, as you will absolutely need that extra capacity. You might even want to plan ahead on this: if you afford to get a boiler with a ball-valve spigot (and possibly a site glass and thermometer), you'll be able to save a lot of effort later. If you can get one that is fitted to take a false bottom, better still.

 

[unionrdr]

I was having pretty much the same problem with my electric stove since I had to replace some dead burners with aftermarket ones from amazon. They heat up a lot faster than the stock ones did. 18 minutes from mash temp to boiling on "HI". Hard rolling boil,1 hour boil off was about 1.5-2 gallons! Boiled off a lot of water,sure,but it didn't effect the beer any.
Now I get the mash water up to 150F with the paint strainer bag in the kettle with a cake cooling rack under that. Mix in the grains quickly,using a plastic paddle to break up dough balls & evenly wet the grains. Wrap the BK/MT in my thinsulate lined winter hunting coat for the 1 hour mash. Trying to maintain temp on the stove didn't work out well. I mash 5lbs of grains in 2 gallons of water.
I was sparging with 1.5 gallons of water against 1.5G in the mash. Since raising the mash to 2G, I now get 3.5 gallons of total boil volume.
I also started lowering the heat to "8.5" on the knob to get a less violent boil,but still gently rolling. Hop utilization is good,& no more than a gallon or a bit less boil off. PB/PM BIAB is working out way better for me with these changes in the same 5G (20qt) SS stock pot I started with. Just going to start adding Super Moss from 5 star for clarity. But this method did get me less boil off,& quality should be better. Taking 2nd FG samples today...

 

[Yooper]

It depends on your climate- you'll boil off a lot more in the desert than you would in Florida- but I normally boil off nearly 2 gallons per hour in the winter, and 1.5 gallons in the summer when I'm brewing at home.

You want a rollling boil, but it doesn't have to be so vigorous as to rock the kettle.

 

[unionrdr]

Those were my thoughts when I lowered the boil from "HI" to "8.5" on the knob. Still rolling boil,but not so violent. Got more acceptable boil off rate that way.

 

[duboman]

You are in MO, it is cold and the air is dry and you apparent;y are boiling a LOT harder than need be! All you need is a nice rolling boil, the wort does not need to be jumping out of the kettle! Tune those burners down to a nice rolling boil and the rate will be less.

Keep in mind that environmental changes like the weather will affect the rate of boil off as well so in the summer with warmer, moister air your boil off will be less as well.

 

[wherestheyeast]

Another thing to consider if you are doing extract batches is the "15-minute" boil method. Check out Basic Brewing Video or the recipe section of HBT under the American Ale category.

 

[unionrdr]

That's sort of what I did with the dark lager recipe I got from ohcrap & modded slightly. It uses a Thomas Cooper's Selction Heritage lager can with other things,including grains. This guy thinks a lot like me,so we decided to compare brews. Anyway,I did a micro mash with carahell,chocolate & rauchmalts. Then did a 20 minute boil with DME's & hops. Added the TCS can at flame out. Fermented with WL029 ale/kolsh yeast betwen 64-69F,it was at 1.012 last week. Should be done & clearing today.
In this instance,I boiled off no more than about 1/2G.

 

[rstump]

I think I'm boiling too hard. This is in a converted half barrel keg (keggle) w/ball valve and when it gets going, I can't see through the steam to judge the boil. The burner BTU is unknown. Old turkey fryer burner I have had for several years. I agree that the easy answer is start with more water.

 

[YeastHerder]

With your next brew you could also find out how far above the minimum heat needed you're at. If you've been way above the setting needed to keep a rolling boil going, turning it down will save a little gas in the long run..

 

[DirtyOldDuck]

I boil off 2 gallons an hour with a good rolling boil (without turning the burner all the way up). One of these days I will see what I get by turning it down more but I am loath to go through the process of determining a consistent boil off rate. Right now I can hit whatever volumes I want and I don't feel like messing with something that is working.

 

[YeastHerder]

I don't feel like messing with something that is working.

Yep, if it ain't broke, don't fix it!

 

[MagicSmoker]

I'll add my recently acquired data to the mix... I have the 30qt turkey fryer from Home Despot. With 6gal of water in the aluminum kettle I can maintain a rolling boil with the regulator dialed back two full turns from max and after 1 hour exactly 1 gallon boiled off (measured after waiting for the water to cool back down to 80F). This is with ambient at 70F and unknown humidity, but probably at least 60% because I wasn't getting shocked from static electricity.

Oh, the inside diameter of the 30qt pot that came with the turkey fryer kit is 298mm so every ~55mm equals 1 gallon (awkward mix of units, I know, but it's way too much of a mess using 16ths of an inch :cross: )

 

[duboman]

I boil off 2 gallons an hour with a good rolling boil (without turning the burner all the way up). One of these days I will see what I get by turning it down more but I am loath to go through the process of determining a consistent boil off rate. Right now I can hit whatever volumes I want and I don't feel like messing with something that is working.

I get the same boil off and agree 100%!