Erlenmeyer Flask Thermal Shock

[BryanEBIAB]

I picked up a small (1L) Erlenmeyer flask at a brew shop a few years ago and the place has since closed down. I never used it much (wife thought it looked cool) until recently when I started doing proper starters.

I just poured about 100mL of near boiling water into it before suddenly realizing that I have no clue what kind of glass it is. I dumped the hot water back into the pot to cool there. It didn’t crack or explode, thank goodness.

What do you think the chances are that it’s a proper borosilicate flask? I’m thinking about putting it through a stress test (after this starter).

1. Safety goggles
2. Place empty flask in a bucket
3. Fill flask with near-boiling water
4. Fill bucket with ice water to meet flask water line

Should borosilicate survive such a test? Any bets on what happens?

 

[bracconiere]

Should borosilicate survive such a test? Any bets on what happens?

i'd bet even if it's borosilicate it'd blow?

 

[Beerstein]

I give it 99% chance its borosilicate.

Unfortunately, there are a quite a few factory rejects being sold on Amazon and other places. Those flaws may include bubbles in the glass that can fracturing.

Your proposed test will stress the glass, even if its good. I'd boil it for 20 minutes, then let it cool down to room temp normally. Then just use it.

This type of lab ware is designed for repeated autoclave cycles. the kind of stress you are proposing may shatter even name brand glassware.

 

[McMullan]

My lab borosilicate bottles routinely go from boiling to very cold water without any issues. Thin walls are usually a problem with Erlenmeyer flasks, especially Chinese knockoffs commonly sold in home brew shops.

 

[bracconiere]

My lab borosilicate bottles routinely go from boiling to very cold water without any issues.

impressive, i had a pyrex casserole dish blow on me when i was making red sauce. i guess they do make glass sauce pans now that i think about it though?

edit: the pyrex dish was probably closer 2 350f though, tomato juice was probably about 60-70f

 

[Bobby_M]

Flasks can take some abuse, but you can take some steps to ease them in to temperature changes. For example, instead of pouring boiling water into a room temp flask, you can run it under some hot tap water first. Same when cooling. Put it in a warm water bath for a couple minutes, then change it out to cold, then add the ice.

 

[CaptMogul]

After boiling my starter I let it cool in the pool for an hour and pitch my yeast

 

[BryanEBIAB]

Great idea putting a carboy handle on it.

 

[CaptMogul]

I am an old timer with Neuropathy in my hands and feet, cant feel a thing. The handles helps me handling the hot flasks off the stove and into the pool.