Boiling in a flask?

Every starter I've made I've boiled in the flask. I have an electric coil stovetop and everything I've read said this is a no-no. Sooner or later, the flask will break. I haven't had any problems yet, but I'd like to avoid any possibility of spilling a liter of hot sticky wort all over my stovetop (and floor, and cabinets...)

So how do other people do this? I really like the convenience and simplicity of boiling right in the flask, plus it makes it easier to chill. I thought about getting a small gas burner, but what about a fuel source? Ventilation issues? What about an electric hotplate? Will it boil 2 liters of water without taking forever?

Thanks!

I have always heard that the direct contact with coils are a no-no as well, I would think a hot plate would be the same. Perhaps a small camping/packing stove running off white fuel or propane would work, just do it outside. Or you could boil the water in a stainless pan and then transfer it to a sanitized flask.

They make chemistry hot plates and flasks for heating. If you have a Pyrex (or similar) flask a hot plate should be fine. If you really want to splurge, get a hot/stirplate combo

Personally, not owning one, I boil in a small pot and pour into the flask

LovesIPA said:

Every starter I've made I've boiled in the flask. I have an electric coil stovetop and everything I've read said this is a no-no. Sooner or later, the flask will break....

Click to expand...

The very first time I tried to boil a starter flask directly on an electric coil stovetop, it cracked the glass. There was no glass-shard explosions and no huge boiling mess, but it pretty much rendered the flask useless after that. I had seen people boiling starter flasks on gas ranges, and wasn't aware that electric coils were different.

Now I've reverted back to my original method of boiling my starters in a small saucepan, chilling, and then funneling it into the flask.

hunter_la5 said:

Now I've reverted back to my original method of boiling my starters in a small saucepan, chilling, and then funneling it into the flask.

Click to expand...

That! But sometimes I simply take my stuff to work and autoclave it :cross:

I would buy a small camping/backpacking propane stove. You could still use it on your kitchen counter and it would work with your flask.

I tried this method my first few times too and got worried like you did. I now use a pot to make the starter wort and a funnel to pour it into the flask for cooling and to sit on the stir plate. works fine, sanitation has never been an issue. I spray the crap out of the flask and funnel with Star San. Easier to control the foam when dropping the DME into the water in a pot than in the flask.

those electric coils would heat the class unevenly and cause it to crack. i boil in my flask all the time but it's a gas stove.

I do a double boil. Put the flask in a pot with boiling water. I don't know if this is a bad way to do it, but it works.

I just noticed mine has a crack recently too. I emailed AHS to ask, and they advocated against any sort of direct heating. Basically using it just as a fermenter rather than a fermenter/pot combo like I had been.

I had a homebrewing friend recommend using a comal (thick piece of metal tortillas are made on) to distribute the heat. Or a double boiler, but if the flask sits on the bottom of the pot it's pointless.

Beernoulli said:

I just noticed mine has a crack recently too. I emailed AHS to ask, and they advocated against any sort of direct heating. Basically using it just as a fermenter rather than a fermenter/pot combo like I had been.

I had a homebrewing friend recommend using a comal (thick piece of metal tortillas are made on) to distribute the heat. Or a double boiler, but if the flask sits on the bottom of the pot it's pointless.

Click to expand...

i don't think AHS would advise you otherwise under any circumstance but borosilicate flasks are used under direct heat in labs worldwide.

They sell heat diffusers at kitchen supply stores. They go over the coils and under the pot/pan (in your case beaker) to even out hot spots. Might work for you.

Irbefan said:

I do a double boil. Put the flask in a pot with boiling water. I don't know if this is a bad way to do it, but it works.

Click to expand...

I was wondering if I could do this. I'm thinking of how I can jams. Putting a rack or even folded tea towel on the bottom of a pot, adding the flask, water in the pot and boiling. It seems this should work.

Irbefan said:

I do a double boil. Put the flask in a pot with boiling water. I don't know if this is a bad way to do it, but it works.

Click to expand...

I have done this too and it is really a nice way to go. If something breaks it is all contained in the pot.