Importance of Boil Intensity

[cegan09]

I've done some homework here, so hear me out. I'm looking for a definition on how much of a boil is enough. I know the biggest impact from boiling is getting things like DMS out of the mix.

My second brew i'm looking to move to all grain BIAB. I have an 8.5 gallon pot and i'm looking to make 3-4 gallon batches. For kicks I put about 6.5 gallons of water in the pot and cranked up the stove. On my largest burner (gas stove) it will reach a boil, though it takes a while. The thermometer in the pot says 210° and my hand held says 212° (need to verify the calibration of both). There are bubbles rising, decent sized ones from the middle. However it's not a vigorous boil. The water is moving around, but nothing like i'd get from a small pot and about a gallon of liquid.

I let it go for an hour and i'm losing about .8 gallons/hour.

Does this sound like it's enough of a boil? If it was just barely boiling, or not really reaching 212° on either thermometer, I could make a call on my own, but where it's kind of in the middle i'm not sure. I'm looking mostly for a judgement call to determine how quickly I get a propane burner and figure out logistics for that (I live on the second floor and pretty sure a burner on a second floor wooden deck is not safe or legal).

 

[GuldTuborg]

If the wort is turning over due to the boil, you've met that "bare minimum" mark. There might be reasons to achieve a more vigorous boil, but they probably fall into the "want" category more than the "need." Does that help establish priorities?

 

[TheHopfather]

What elevation are you? Water boils at different temperatures at different elevations, once it reaches boiling it won't get any hotter. Boiling is boiling. As long as you've figured out your boil off rate you'll be fine. I boil off ~1gal/hr on my system, you aren't far off from that, I'd think you'll be fine.

 

[cegan09]

Yes, thank you.

Guess I'll try a batch or two on the stove before moving to a propane burner outside. Should let things warm up outside as well.

Edit, close enough to sea level to not worry about it. Southern NH (basically MA)

 

[helibrewer]

You should be fine, just adjust your recipes for your actual boil off. Also use a kettle fining agent since a more vigorous boil helps with protein coagulation, you might go as far as using ClarityFerm in your fermenter also.

 

[slym2none]

My boil is not the most vigorous in the world, but it gets a hot-break going at the boil, so I figure it is fine. I surely don't have any DMS problems.

 

[frazier]

You could do what I do - split the boil into two pots on different burners. Good rolling boil achieved. Split the hops 50-50. Works for me!

 

[unionrdr]

I use an even, rolling boil. Nothing too aggressive. If it blops like lava, it's to aggressive.

 

[GuldTuborg]

If it blops like lava, it's to aggressive.

Or too viscous. Don't boil that much!

 

[unionrdr]

I boil about 3 1/2 gallons in a 5 gallon kettle myself. Wide open heating element makes it bloop bunches of bubbles like lava. So I turn it down to a gently rolling boil.

 

[Azbrewboy77]

I'm curious as well , I've been doing 1 gallon beers for tests on an advantco 1800 & its 212 but barely noticeable

 

[Tactical-Brewer]

I just started doing 5 gallon batches on my electric stove with a 7.5 gallon aluminum kettle.

It definitely doesn't boil vigorously, but hits 212, proteins coagulate, and have a measured boil off rate similar to yours.

I figure, if anything, I'm spoiled! Cause when I do move up to a keggle on the propane and start doing bigger batches, I'll really have to watch it for boil overs. At this point, I can have 6.75 gallons in the kettle and am absolutely comfortable.

Tac

 

[Subdivisions]

You're getting a good enough boil. I burn off about the same amount of liquid per hour. I straddle 2 burners on the gas stove and get a good rolling boil with 6.5 gallons, which isn't vigorous by any means, but still a boil. I get a good hot break and the beer turns out quite well.

I'm at about 1100ft altitude so 210 is a boil here and I hit that, test your thermometers in a smaller boil and see what they read.

 

[cegan09]

Sounds like once again my engineer mind was overthinking things. Good to know.

Buying grains this weekened for my first BIAB batch. Will brew next week some night after work with a friend. Should be fun.

 

[GuldTuborg]

Sounds like once again my engineer mind was overthinking things. Good to know.

No, it's good to think about this kind of stuff, if only to prioritize how to upgrade equipment. If you want to make world class Scottish ales, for example, you need to have a big burner, or learn some other way to compensate. Like to make barleywines and other really big beers? You need to either boil harder, double mash, or be satisfied with long brew days of slow boiling. Like I said, there are situations where it's very helpful to get a lot of heat on the wort.

 

[cegan09]

Very fair.

I think i have a good plan. I'm happy sticking to 3-4 gallon batches for now. That way when it's not great, I don't have a ton to waste. When it is, I can build on it. I'll learn what I can over the next year on the setup I have. Maybe during the warm months I'll buy a propane burner and enjoy my backyard. Next year, when I finally buy a house and get out of this apartment, I'll upgrade to suit what I like brewing.