Boiling in Flask?

All

Just order a stirplate...and a 3000ml flask.

Am I able to use the Erlenmeyer flasks on a glass stove... then right into cold water?

I do it no problem, but you could be better off in a SS stock pot. The heat transfer of Pyrex blows!!!! You'll be shocked how long it takes to boil, then how long it takes to cool. Another issue you WILL encounter is a volcano effect due to the shape of the flask.

On gas you should will be fine. I have heard that people should never boil a flask on an electric stove. I'm not sure why.

I do it all the time with a *gas* stove. What the hell's a glass stove?

But you should buy some foam control for this. It'll want to boil over constantly if you don't add a drop or two of foam control.

A glass stove is exactly the same as a gas stove... Just spelled wrong.

jalgayer said:

A glass stove is exactly the same as a gas stove... Just spelled wrong.

Click to expand...

Hahaha! Nice!

You'll be good then as long as you get some foam control. If you don't you'll be standing there the whole time blowing down the foam and sticking something in there to try to break the forming head, or you'll have a bunch of boil overs. Something about the cone shape makes it boil over way more easily than normal.

The second mine reaches a boil I consider it done. I have a oven mitt and I will take it right off the heat and put in an 8 qt pot should I not get it off in time.

I heat my Pyrex flask on my electric ceramic top oven ALL the time. For whatever reason I'm still never comfortable with it.

I have a glass top electric stove and will put a coat hanger between the stove top and flask. Electric stoves get super hot and my 5L flask was not cheap. Using an infrared gun to check the temp easily pegs it so it's over 500F.

I have a 2500 ML Erlenmeyer. Use it on my gas stove all the time. A few drops of foam control helps. You can take it from the stove immediately into an ice bath. Except that I do not let the ice water get above the liquid level in the flask. I also, after removing the flask from the stove, slide (not drop) down the slide my stir bar. I experienced no big delays in the boil ( it's only a 15 minute boil anyway) or the cool down in the sink. I use a foam stopper, too.

I assume he actually meant a "glass top" stove. I have one and I boil a flask on it regularly. I have heard that it is not a good idea, but no problems so far.
The volcano effect is the main deterrent because you have to watch the flask pretty carefully for when it starts to boil.

Edit: my bad. I didn't realize that the OP was the same as the person that made fun of his spelling. I guess he really did mean "gas"

The question then becomes why not use a beaker instead of a flask?

How do you heat a beaker on a glass stove and can a beaker let you get to at least 1 liter?

You could use a beaker but the opening is much bigger which means more potential for bacteria to land in it when you pitch the yeast in it or while decanting, etc.

I have not done it yet but, I have some instructions for boiling on a electric stove. It says to put the flask in a pot with water to boil safely.

Those of us who make science for a living heat Erlenmeyers directly on ceramic-top hot plates all the time (e.g. http://demo.physics.uiuc.edu/lectdemo/descript/1092/WaterBoiling.jpg), so glass-top stoves shouldn't be a problem. YMMV.

I'm curious about the surface temp of a hot plate vs. an electric stove. I can boil 5 gallons of water on one burner on my electric stove...will a hot plate do that?

dstar26t said:

I have a glass top electric stove and will put a coat hanger between the stove top and flask. Electric stoves get super hot and my 5L flask was not cheap. Using an infrared gun to check the temp easily pegs it so it's over 500F.

Click to expand...

I have a glass-top stove as well and I put my flasks directly on the burner with no problem whatsoever.

For some reason, I'm only cautious when it come to brewing.

The dial says it gets up to 450 C, but I never really take it higher than about 200 C (390 F). But I'm just boiling 250 mL of nitric acid, usually.