dms worry

DMS boiling point is at 98-101 F, so you're fine as long as you didn't cover the pot with a lid.

 

I would like to know how long was your boiling time, I think if you boiled enough time with no lid or enough gap on your kettle tun, the only risk is to get a chill-haze trouble due this poor boil temp.

 

You're probably fine. If you continue to brew on the stove you'll probably spend a lot of time getting up to a boil. You might consider one of these://www.amazon.com/Allied-Precision-Premier-742G-Bucket/dp/B000BDB4UG/ref=sr_1_1?ie=UTF8&qid=1379642510&sr=8-1&keywords=bucket+heater

or a heat stick.

 

Two things to try...
1) Cover the pot with a lid until rolling boil begins.
Lift and tip the lid periodically to drain the condensate into a bowl to prevent it from returning to the boil.

2) Cover the pot with a lid until rolling boil begins.
Consider getting a fry-pan splatter screen to cover the pot.
It may be enough to retain heat and maintain the boil while allowing the steam to escape.

My set-up is a combination of both.

3) CW is, stir the wort often if you can reach / maintain a vigorious boil.

 

When I brewed on the stove, I had the same issue on a couple of occasions (slow to no boil). I still evaporated off plenty of water. I you lose 10%+ of you're starting volume, you're probably doing ok. I never really had a dms issue from using a stove.

In addition to the above suggestions, you can also try a more concentrated boil (which is easier), and then add back water into the fermenter.

 

not to worry about DMS as others have mentioned. you almost have to work to brew a beer with noticable DMS. just cover the pot. you do want a vigorous boil for other reasons though.

i am suspicious that your thermometer is not accurate, or at least not accurate enough. remember that water boils at 212, and no matter how much heat is applied to the wort, the dial will not read above 212. you would get alot of vapor boiled off, but 212 is the max reading. the wort might be rolling and jumping out of the pot, but it's still 212.

so is it possible you did achieve a weak boil but your thermometer is off a degree or two?
Cheers.

 

If he is in Chicago at 583 ft above sea level, boiling will be 210.9F. About what he stated.

Coors makes clean AAL brewing at 5675 ft above sea level, with a boil temp of 201.7 F.

DMS has a boil point of 99F, so as long as you have a decent boil off rate, the DMS will be carried off.

 

so then yes, we have a boil. weak perhaps, but boiling none the less.

maybe i'll recalibrate. i'm close to 1,000'. i always assumed the change is almost nil until you get to Denver altitude.
Cheers.

 

I'm at 900 ft above sea level, and boil temp is 210.4 F here.

 

I would just like to point out that it is possible to tell if your wort is boiling just by looking at it. No thermometer required.

 

What? No way.

Next you're gonna tell me that it's possible to tell if the beer has DMS by tasting it.