Flasks on electric cooktops

[coypoo]

Is it ok to boil water in a glass flask on an electric cooktop?

 

[BMan1029]

I'm going to go with no on this one. The one time my brew buddy did it inside on the electric stove, when he went to pick up the flask after it was done boiling, it shattered and now he is the proud owner of 2nd degree burn scars on his foot.

 

[coypoo]

Crap, that is what I thought the answer would be too

 

[Boerderij_Kabouter]

Use a few plys of tin foil under the flask and you are good to go. The problem occurs when the heat from the electric coils is to concentrated (if that makes any sense) and localized. This creates stress within the glass and can cause to fatigue within the material and eventual breakage. The tin foil spreads the heat and the fracturing is avoided.

 

[coypoo]

Use a few plys of tin foil under the flask and you are good to go. The problem occurs when the heat from the electric coils is to concentrated (if that makes any sense) and localized. This creates stress within the glass and can cause to fatigue within the material and eventual breakage. The tin foil spreads the heat and the fracturing is avoided.

Would putting it in a pot with water on the stove be similar then?

 

[sapperxl]

It depends on the cooktop too, mine is ceramic with the elements under that and is fine for borosilicate glass. The ones where the flask goes directly on the element are the problem.

 

[Zamial]

HUH??? I use my e-flask on my electric coil stove top with no issues other than it boils over REALLY easy...

I also use almost all pyrex cookware exclusivly on my electric range... borisilicate glass should have no issues. If you have a super cheap e-flask it my not be borisilicate...it should say on it if it is.

 

[Lennie]

I've used mine many times on my electric coil stove but I've always known there is a chance of the glass breaking. To minimize the possibility of a problem I use a medium heat setting to give the glass in the flask time to heat up gradually and distribute the heat. I also handle it with a hotpad, and wear shoes and pants. I lift it straight up off the burner and set it nearby on a hotpad when its done boiling.

There is supposed to be some little wire deal you can put on the coil, then set your flask on that to keep it off the direct heat of the coil, but I never used one.

 

[Boerderij_Kabouter]

yes a pot of water or just a pot will be have the same effect.

Zamial, I do not know. I have always heard precautions should be taken when cooking with glass on electric or otherwise. If it works, do it.

 

[Hammy71]

I'm very paranoid about my flask. I know they are rated to go from hot to cold (ice water bath), but I just can't bring my self to do it. I boil my starters on the electric stove in a pot, cool the pot in a sink of cold water and then transfer the wort to a sanitized flask. Little more work, but saves my sanity.

 

[Seven]

I boil my flask on an electric stove-top that has a glass/ceramic top. No issues so far other than it does make me nervous so I boil on the lowest setting possible to maintain a decent boil.

 

[coypoo]

I'm very paranoid about my flask. I know they are rated to go from hot to cold (ice water bath), but I just can't bring my self to do it. I boil my starters on the electric stove in a pot, cool the pot in a sink of cold water and then transfer the wort to a sanitized flask. Little more work, but saves my sanity.

I must finished doing the same thing. I just spent $22 in the flask and don't want to break it just yet bc I am clumsy and don't trust myself with hot glass just yet

 

[HolidayIF1488]

I do it all the time. If you are one of the ones who get nervous a pan w/oil(canola or vegetable) helps even out the heat.

 

[Spartan1979]

I tried a pan and the flask was rocking so much it made me nervous.

 

[bighorn_brew]

If your handy with 2 pairs of pliers you can bend a coat hanger or two so that it barely lifts the flask off the top of the ceramic cook top or coil heating element. I saw commercial examples that I just copied....

 

[Lennie]

If your handy with 2 pairs of pliers you can bend a coat hanger or two so that it barely lifts the flask off the top of the ceramic cook top or coil heating element. I saw commercial examples that I just copied....

I've seen those ut I ever understood why it would work. I guess its just one contact point, not hot/cold/hot like a coil does.

 

[bighorn_brew]

I believe by lifting the flask up off the burner the flask bottom heats up through radiant heat, instead of through direct conduction, so by doing it radiantly it relieves some of the expansion/contraction stress between the hot bottom, and the cooler (colder) upper portion of the flask...or least that is my intuition...

 

[Hang Glider]

My flask lasted about a year...

I had never heard not to do this, so my flask and my electric stove were partners. However, one day, the stress caught up with it. Even Pyrex can't handle it repeatedly, it seems.

I set it into ice water to cool, and lost all my boiled wort. Fortunately it didn't waste the yeast, nor cut me. Just cracked and dropped the bottom into the icy water.

Now, I use a saucepan and transfer to the flask.

 

[bighorn_brew]

I think a better way (I haven't done it this way, but may in the future) would be to use a hot (brought up to boiling of course with flask in, not just dunked in) water bath, and use a lifter under the flask....extra insurance, plus if it breaks, it's doing to just break into the pot, not all over the stove....

 

[Lennie]

I always set the heated wort off on a hotpad to cool some before throwing it in cold water, I think thats asking for trouble no matter how you heat.

Will wort boil in a water bath? I'd think its boiling point would be higher than water. I like the oil bath idea but I really think boiling in a pan and adding it to the flask while hot might be the simplest method. You get the sterilizing effect of boiling liquid that way.

 

[broadbill]

I always set the heated wort off on a hotpad to cool some before throwing it in cold water, I think thats asking for trouble no matter how you heat.

This is what I do as well. I try to avoid big temp differentials and sudden temp changes.

I heat directly on a ceramic cooktop, but would use a diffuser (pan bottom, wire, etc) if I were doing it on an element cooktop. Big differential there. (800F element, 100F water =bad).

I think heating cool water to boiling is a slow enough transistion that you aren't stressing the glass too much.

Same goes with cooling...putting 212 F wort/flask in cold/ice water (35-45 F), cant be good. Another big differential.

 

[Darwin18]

Do you boil the wort in your carboys or do you sanitize them? I don't understand the need to boil starters directly in your glass flask. The odds of breaking the flask or burning yourself are not worth the sanitation benefits. Just sanitize with Starsan for the recommended contact time and you're ready to go.

 

[luke2080]

My flask lasted about a year...

I had never heard not to do this, so my flask and my electric stove were partners. However, one day, the stress caught up with it. Even Pyrex can't handle it repeatedly, it seems.

I set it into ice water to cool, and lost all my boiled wort. Fortunately it didn't waste the yeast, nor cut me. Just cracked and dropped the bottom into the icy water.

Now, I use a saucepan and transfer to the flask.

I had 2 flasks at the same time...both lasted about 1 month. I put them directly onto the coils, which didn't seem to be an issue. I think the problem is I was dumb, and I stick them directly into the freezer. Both eventually formed small cracks on the bottom, which would leak like a drop or two of wort. But I tossed them since once you have that imperfection you are asking for trouble.

For my new flask I still put it directly on the coils, but let it cool 15 minutes, then put it on a pad in the freezer (Ice bath takes too long, wastes ice, and I don't have a stopper for my sink so its a moot point). the problem was putting it directly on a frozen metal surface. Also the problem may have been me being an idiot.

Although, most of the time I do now just boil the wort in a saucepan, stick that in a freezer, then transfer. The only purpose of my flask now, is that it is a good medium to sit on a stir plate.

I wish I had just build larger stirplates and used growlers instead of a flask.

This should be the next debate if its not already. To use flask or to not. (As opposed to glass vs plastic carboys)

 

[broadbill]

Do you boil the wort in your carboys or do you sanitize them?

Don't use carboys for the most part...those suckers are dangerous!

I don't understand the need to boil starters directly in your glass flask. The odds of breaking the flask or burning yourself are not worth the sanitation benefits. Just sanitize with Starsan for the recommended contact time and you're ready to go.

I usually make up Starsan on brew days and don't have any ready to go a few days before when I'm making the starter. Also, its nice to not have to do dishes after making a starter.

 

[SlimeyBooger]

I have a glass top electric stove and normally boil in the flask and cool in ice water and haven't had issues so far. Although, if I need to make more than about 1600ml of starter it's pretty difficult to keep from boiling over so I'll just use a pot.

 

[kh54s10]

I have a glass top stove. I bought what I think is a good flask. I raise the temperature somewhat slowly. I put a pan of hot water in the sink. I let the flask cool a bit then put it in the pan. I then start a slow stream of cold water. Then I add ice. It takes about 15 minutes to a half hour. No fears. --- so far ---

 

[Whippy]

To be safe, I would go to the camping section at Wal-Mart and buy a small one-burner "cook stove" and a three pack of propane (the small green "disposable" bottles). You can probably do this for around $15-20 bucks USD or so.