Warning: Borosilicate Erlenmeyer Flask not THAT strong...

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rshosted

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OK, I figured I'd post this to you all as a warning to not repeat what I did this weekend. I have used a 5000 ML borosilicate Erlenmeyer flask for the last year. I've used this flask on direct gas stove top oven and placed it into ice water many times with no problem.

Yesterday, I was out in the garage, so I decided to throw my 5000 Starter on the Brewturtle (my name for my brew sculpture) and crank up the heat. I put it on the smaller banjo burner at 55K and after about one minute, I heard pop and saw 5 liters of starter wort falling to the floor.

So what I got out of this, and if anyone knows better please correct me, but Borosilicate glass will withstand average stove top burners (13K BTU) but if you really want to speed it up, your going break it and will have to throw down another $50 for a new flask (like I did). The only saving grace is that it was outside so I could hose it down fairly easy...
 
" 3.) Borosilicate glass will withstand a fair degree of thermal shock but unless your intent is to see if you can make it crack, don't toss recently heated glass into a cold water bath. "

"Boiling Flasks. These borosilicate boiling flasks (florence flask) are made to ISO 1773 and are highly resistant to breakage due to heating or chemical attack. A flat bottom boiling flask can be used on a wire mesh, a round bottom one needs a clamp and bosshead. Use instead of an erlenmeyer flask if vigorous boiling is required."
 
Not to seem insensitive, but I'd never even consider putting glass (tempered or not) on any burner with more power than a conventional gas stovetop!
 
Even on my stovetop, on the small 7kBTU burners, I only run them at medium. After boiling, I let the flask sit to cool to under 200F before I move it to a cool water bath. Then I wait a bit more before I dump the ice in the sink. Just because borosilicate is shock resistant doesn't mean you should continually test the limits of that claim. I hear modern car bumpers can take a 5mph impact without any damage but I don't go bumping brick walls every day.
 
Live and learn I guess. Just figured I throw it out there for those that don't know. Not like I was gonna put it on my 350k banjo burner :)
 
I have a 5L flask and when I cook my starters, I use a griddle pan that I never bothered using on my out door gas grill. I put it right on top of the stove on the center burner and try to center the flask as much as possible. I'm not keen about putting the flask directly on the grate. I didn't want to give the opportunity to create some sort of pattern on the bottom of the flask. I usually wait a few minutes before I chill it down, not that I think there is much of a difference between 212 and 200 going into an ice bath in my sink...
 
Not all borosilicate glassware is made equal. Teaching grade E-flasks go for around $50, while the research grade E-flask we buy at the university chem store cost us $70-100. As with anything you get what you pay for. I suspect research grade glass is a little thicker to withstand being handed down from PI to PI over successive years, while teaching grade reflects the disposable nature of most classroom equipment.
 
Since I'm in the market now, how do you tell what type oNe is buying? So I don't pay more and still get a teaching one? Thanks for that info, that is great to know.
 
What are the pyrex flasks made of? I have two 2L pyrex and was looking to get a 5L in the near future. The pyrex have been abused. I have taken them off the stove with boiling wort and put them in the sink immediately. I try not to but sometimes I'm not paying attention to what I'm doing or I get a rushed feeling.
 
rshosted said:
Since I'm in the market now, how do you tell what type oNe is buying? So I don't pay more and still get a teaching one? Thanks for that info, that is great to know.
Click to expand...

Im pretty sure unless you buy directly from a science supply store you will not get the heavy duty research grade flasks. When I asked the guy at the university chem store about prices they seemed to run ~$50 per liter, luckily I managed to find a unused 3 L E-flask hidden in the back of our labs cupboards that I now use for starters (it's clean, no harmful chemicals/bacteria).
However, even a cheap flask should last you indefinitely so long as the common sence precaution of letting the glass cool before dunking in cold water is followed.
 
The shock that can make it break is from the Temperature differential. So instead of waiting 5-10 min for it to cool from 212-200 with air just dunk it in sorta cold water first. 212-65F < 200-32F. When you get the temperature down some add some ice
 
boiling in the flask always produces a volcano for me anyway.

i just boil in a 4 quart (or 8), dump in an ice bath then pour into a sterilized flask.
 
I got a question for you all that have a 5L flask, where did you get a 5L flask and what did you pay?

I have a 2000mL and it works great but now Mr. Malty is telling me that my starters need to be bigger. about a gallon or so, now I need a larger flask for my stir plate. Ive been looking but cant seem to find a reasonable sized flask (4000mL and up) for a descent price.

Any help? Thanks in advance.
 
ArtVandelay said:
You might be able to just use a gallon sized glass jug. These run <$5 usually.
Click to expand...

I had to make a starter that was 1.26 gallons and I'm just going to use the stock pot its in but I figured that if I'm making starters this big again I would just buy a larger flask, but in doing research i cant find a good price on a large one. $80 for a 4L flask just seems to high plus that doesn't include shipping.

I have played with a milk jug (cant get a vortex) and I cant find a glass jar that's big enough, and cant find something with a flat bottom.
 
I ordered from Cole Parmer, and they also have a web site. It was $72.66. I would not order from them again. I ordered on 1/10/11 and they did not ship until 1/18/11. I should get it tomorrow.

I tried to get by without the big flask, and just keep running into I need bigger starters for my batches. I recently just bought 4 yeast samples for one 10 gallon batch. Ultimately, I spent so much on yeast I could have spent it on the flask and I still under-pitched by a little...

Part of the reason I chose cole parmer is because they clarified they were not 'student grade' which IS cheaper, but I (obviously) need a more robust flask.
 
I usually shut the heat off, prepare a shallow pan with ice water, then pour lukewarm tap water down the side of the flask for a minute before placing in the icewater. Maybe overkill, but it hasn't cracked yet either.
 
Sorry to hear about your purchase.

I've started doing 10-12 gallon batches and everything (I thought) was fine until I calculated my yeast counts and I have been grossly underpitching my last 4 batches. But I've been hitting all my numbers!?!? Go figure. I'm a perfectionist and just want to make sure I'm calculating correctly and adding everything to the numbers.
 
I boil my 5L on a trivet on the electric stove. After boiling, it's removed and placed in the sink and I run cold water over it (detachable hose type sink faucet). Actually, lately this winter, I haven't even used ice.
For bigger starters, I use a 3 gallon carboy with a barbell stir bar on a big stir plate.

 
DakotaRules said:
I had to make a starter that was 1.26 gallons and I'm just going to use the stock pot its in but I figured that if I'm making starters this big again I would just buy a larger flask, but in doing research i cant find a good price on a large one. $80 for a 4L flask just seems to high plus that doesn't include shipping.

I have played with a milk jug (cant get a vortex) and I cant find a glass jar that's big enough, and cant find something with a flat bottom.
Click to expand...


http://www.williamsbrewing.com/5000_mL_YEAST_BOTTLE_P2595C108.cfm

It's big and a favorite tool in the brewery!
 
For what it's worth. Morebeer's deal of the day WAS a 5000ml flask, for $20. Needless to say, they are sold out now ;-)
 
Wish I would have known about morebeer this morning! or 20 minutes ago! Oh well better luck next time.
 
An alternative to making huge starters is to make a more normal sized starter, decant the liquid, then add more starter wort on the cake. This stepped method takes longer, but it eliminates the need for huge starters and oversized glassware.
 
I have some borosilicate boiling flasks I prefer to use. Erlenmeyers are still used on the stirplate though
 
Just a warning. Even with a trivet on my electric burner the 5L flask I got for christmas cracked after just minutes of turning on the burner. I'm so pissed I can't even express it right now. Never had a problem with my Pyrex brand 2L flasks but this no-name Chinese-made POS cracked in a second.
 
smokinghole said:
Just a warning. Even with a trivet on my electric burner the 5L flask I got for christmas cracked after just minutes of turning on the burner. I'm so pissed I can't even express it right now. Never had a problem with my Pyrex brand 2L flasks but this no-name Chinese-made POS cracked in a second.
Click to expand...

Sorry for the loss!

Maybe helps the next guy, you really need to put the flask into a pot of H20 instead of using a trivet. I realize that the Pyrex has served you well, but they don't make them as well as they used to, especially the knock-off crap.
 
I've always thought I should get a group together and order a bunch from here:
http://vwrlabshop.com/search.asp?t=ss&ss=Erlenmeyer&x=4&y=11

Have to be local though, cause I wouldn't want to re-ship these things.

FYI these guys have stir bars and all kinds of neat lab toys available to the public. Fast to ship and very helpful on the phone. They were always my go to place back when I was doing Field Research.
 

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