Qestion about heating a Flask on a stovetop for starters...

[brettanomikey]

OK, I have a Erlenmeyer Flask, they recommend only heating over a gas stove. I don't have a glass stove, I have the electric coil stove. I would love it if I could just throw my flask with wort onto my coil stove to boil it, but am afraid to screw something up. Has anyone done this successfully???? Should I not risk it???

It's such a pain to boil separately and sanitize, blah blah.

[brewinhard]

What about using some wire guauze or even aluminum foil under the flask to boil and disperse the heat?

[Bugeater]

The reason you don't put a flask directly on the electric coils is uneven heating, i.e. red hot metal right next to cooler air space right next to red hot metal, etc. Glass doesn't disperse heat well so heating in stripes puts an incredible amount of stress on the glass due to uneven expansion.

The easy way to handle this is to simply make a simple trivet out of coat hanger and lay that on the burner with the flask on top of it.

My way is even simpler and quicker on brew day. I pressure can my starter wort in quart jars a couple times a year. That way when I want a starter I just sanitize a flask and the outside of the jar, pop it open and pour the wort into the flask. I never have to heat the flask at all.

Wayne

[BeerPal]

I don't have a gas range in the kitchen, so I make my starters on a propane camp stove in the garage.

[Stinkfist]

Is it ok to use one of the glass top stoves to heat it? It seems to have a pretty even heating surface? I have always just heated it in a pot and added it to the flask cuz everyone said to not use it on an electric stove but after hearing this I think it may work just fine on my glass top...any agree?

[bluelou6]

I have heated them successfully on my glass top stove. I wasn't 100% comfortable with it though so I use my side burner on my gas grill.

[Travisty]

I layer up some aluminum foil on top of the coils of my electric range to even out the heat under the flask. I have had a couple of cracks formed, but I'm fairly certain that's been because of the too rapid of cooling I was subjecting the flasks to with a cold water bath. Now I let them cool in warm water first then use colder water. So far so good.

[brewranger]

As long as your flask is borosilicate (pyrex) rapid cooling should not cause any cracks.

+1 to bug's comment about uneven expansion.