Electric Stove Erlenmeyer Flask Starter Boiling

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iceman80403

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It appears it is possible to boil starters in an Erlenmeyer flask on "old fashioned" electric stoves.

I've read all I could find online and everything says to only boil Erlenmeyer flasks on gas stoves. There have been some unsuccessful attempts on this forum with sand or water and another pot to dissipate the heat on an electric stove resulting in no boiling or a broken flask. I attempted what chillHayze said he uses with success on an electric range.

I used a 6" burner plate and a 2000mL flask on medium heat to bring over 2000mL of water to boil on my stove and boiled it for about 1/2 an hour then increased the heat to high and boiled for another 1/2 hour with no exploding glass and boiling water bombs which I was very nervous of!

I then placed the flask in a sink of cold tap water to cool it down without cracking. I didn't use ice cubes in this trial because I wanted to minimize the temperature differential which is also why I brought it to a boil on medium power.

I then brought the flask with fresh tap water to boil using the burner on full power without it exploding and also cooled it successfully with ice water.

The following is a video of the flask boiling:


The following is a video of the flask being immersed in ice water. Obviously, I didn't have much ice on hand.


I hope this helps everyone who is worried about boiling starters in an Erlenmeyer flask on an electric stove. It should be stated that I have never made a starter and this is the beginning of my experimentation into making them. I'm currently in the process of making a stir plate and I'm considering making a very detailed "how to" to make one.
 
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I boil my two liter flask on the electric stove regularly. What is needed is a trivet to place on the burner coils. This separates the red hot burner coils from the glass flask. The flask can crack when it comes into direct contact with the hot coils.

I salvaged a couple of iron burner grates from an old gas stove. I put one of these upside down on the electric burner coils and place the flask on the grate. This works basically the same as a wire trivet would. One thing I really like is that the grate is somewhat concave when upside down and it cradles the flask nicely. The second grate I put in an old enamel pot. When cooling the wort, I put the flask in this pot and circulate cold water through it. The grate keeps the flask up off the bottom of the pot allowing cooling water to get under the flask as well as around it which speeds up the cooling process considerably.
 
I've never heard NOT to use it on electric stoves, and to use it on gas only...I have boiled in my flask twice on my electric stove, with no problems....

But Honestly, I am a little uncomfortable doing it, because I got mine from work here at the medschool, and I really don't know how old it was when i was given to me. It could be 2 years old or it could be 30 for all I know.....So having had old pyrex plates and baking things, given to me from my parents, go bad and break after 30 years or so, I just don't feel comfortable doing it.

I just use a pan...but for a brand new flask? I wouldn't have a single worry about doing it.
 
You can make a trivet out of a metal coat hanger, bend it in the shape of a star and cut off the excess. They used to sell something like this with pyrex kettles way back when.
 
I've never heard NOT to use it on electric stoves, and to use it on gas only...I have boiled in my flask twice on my electric stove, with no problems....

But Honestly, I am a little uncomfortable doing it, because I got mine from work here at the medschool, and I really don't know how old it was when i was given to me. It could be 2 years old or it could be 30 for all I know.....So having had old pyrex plates and baking things, given to me from my parents, go bad and break after 30 years or so, I just don't feel comfortable doing it.

I just use a pan...but for a brand new flask? I wouldn't have a single worry about doing it.

You can frequently get away with it, but odds are that eventually the flask will crack. It could happen tomorrow or years from now and there is no way to predict when it will happen. Do you feel lucky?

As Joe C. mentioned, Corning used to make an all Pyrex glass stovetop coffee percolator and it came with a wire trivet specifically for this purpose. I don't know if they still make the percolator or not, but I doubt that Pyrex has changed much if at all since then.
 
Did this just the other day, using a glass top electric stove. Worked ok, but left a nasty ring around the glass bottom, and seemed like a lot more work then just doing it in a sauce pot and pouring it in afterwards.
 
I've used mine on the stove regularly as well, but after having it on my stir plate yesterday for 24 hours, there was a huge crack along the bottom and up the side when I picked it up. The stir bar was not going crazy and it had a nice vortex going. I'm guessing it was from tempering the glass too many times from the boiling to chilling process and having the stir bar vibrating it ???

Has this happened to anyone else?


I'm gonna give it a try again with raising it above the burner and chilling it a bit slower.
 
Did this just the other day, using a glass top electric stove. Worked ok, but left a nasty ring around the glass bottom, and seemed like a lot more work then just doing it in a sauce pot and pouring it in afterwards.

+1 and the hot break shoots up the neck of the flask in a hurry!!:mad:
 
You can frequently get away with it, but odds are that eventually the flask will crack. It could happen tomorrow or years from now and there is no way to predict when it will happen. Do you feel lucky?

As Joe C. mentioned, Corning used to make an all Pyrex glass stovetop coffee percolator and it came with a wire trivet specifically for this purpose. I don't know if they still make the percolator or not, but I doubt that Pyrex has changed much if at all since then.

And guess what, in the, wow, in the 5 years since this post I have learned my lesson. I cracked the original one I was using when I posted this, which I chalked up to it being an over 10 year old flask....and a new one not too long ago. And the funny thing is, I rarely ever boil in them, I find a pan works much better, but when I'm in a hurry I think, this will save a couple steps...but so not worth it.
 
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