Erlenmeyer Flask Question

[altone]

Just a quickie for someone who knows about these things.

Does anyone know the differences between Heinz Herenz and Schott brand flasks?

Are the Schott flasks thicker/stronger or are they similar in quality.

The Schotts cost a lot more so hoping the cheaper ones will be fine.
Will be using them for yeast propogation.

Thanks folks.

 

[Online Brewing Supplies]

Just a quickie for someone who knows about these things.

Does anyone know the differences between Heinz Herenz and Schott brand flasks?

Are the Schott flasks thicker/stronger or are they similar in quality.

The Schotts cost a lot more so hoping the cheaper ones will be fine.
Will be using them for yeast propogation.

Thanks folks.

I dont know about Heinz but schott/Duran is good quality as well a being thick walled.I also have some cheaper CZ brand flasks Simax which are good as well, both handle direct flame to chill very well.
GB

 

[Leigh]

Just make sure they are boro-silicate (i.e. pyrex) and not shonky low grade or thin glass.

The issues with thin pyrex vessels come about:
- if you heat them on a hot plate and you spill some liquid on the hotplate, you can end up with superheated spots between the hotplate and flask resulting in the flask cracking,
- If you are rough (like me) with your glassware they break more easily,
- If you are using vacuum on the flask they be stressed with no visible signs and fail later, and
- If you have volumes greater than 2L the bottom can fall out without notice

Not all of these are relevant to brewing at home, but it will depend what you are using them for.

For mine, I always like to pay a little extra for the better quality. GB's advice is good, schott and duran are very good brands. I have also not heard of Heinz Herenz so won't comment on that one.

 

[altone]

Just make sure they are boro-silicate (i.e. pyrex) and not shonky low grade or thin glass.

...

Yep they are borosilicate, I might buy both brands in 250ml as they're cheap at that size, to see if there are any visible differences ie. thickness, then buy my larger flasks based on this.

Thanks for the quick replies guys.

 

[captaincleanoff]

i had a 5l flask which I 'borrowed' from work. I was boiling up a starter on the hot plate last year, and the bottom of it cracked.

I have since got another 5l erlenmyer flask from craftbrewer... but I have been too scared to put it straight on the hotplate again..

Do you guys put it directly on the hotplate? Its possible that the first one I got was not very good quality, which is why it broke..

The craftbrewer one looks much thicker so I suppose it will withstand more heat...

 

[Online Brewing Supplies]

i had a 5l flask which I 'borrowed' from work. I was boiling up a starter on the hot plate last year, and the bottom of it cracked.

I have since got another 5l erlenmyer flask from craftbrewer... but I have been too scared to put it straight on the hotplate again..

Do you guys put it directly on the hotplate? Its possible that the first one I got was not very good quality, which is why it broke..

The craftbrewer one looks much thicker so I suppose it will withstand more heat...

Dont know about craftbrewers gear! What brand is it? I use a gas burner/stove and put a stainless mesh over that (flame) then the flask on that.You didnt heat the thing empty did you?.That will stuff any flask.
GB

 

[therook]

i had a 5l flask which I 'borrowed' from work. I was boiling up a starter on the hot plate last year, and the bottom of it cracked.

I have since got another 5l erlenmyer flask from craftbrewer... but I have been too scared to put it straight on the hotplate again..

Do you guys put it directly on the hotplate? Its possible that the first one I got was not very good quality, which is why it broke..

The craftbrewer one looks much thicker so I suppose it will withstand more heat...

exactly the same thing happened to me but Leigh has come up with what happened to mine....

- if you heat them on a hot plate and you spill some liquid on the hotplate, you can end up with superheated spots between the hotplate and flask resulting in the flask cracking.

Looks like i'm buying a new one

Rook

 

[Brewmeister70]

Is it a stupid question to ask if anyone has ever tried heating them on an electric element stove top?? That's what I've got and am about to try using th Stot brand in 2 and 5L sizes for the first time and would love some feedback before buggering the flasks...

Thanks guys.

 

[Ross]

Even with boro-silicate (which ours are) I wouldn't recommend using a hot plate.
A gas flame is fine though.

Cheers Ross

 

[Cortez The Killer]

I heat mine (3L, 1L, 250mL) on hot plates all the time

No issues

Can't remember the brands - they came from http://livingstone.com.au

Cheers

 

[pdilley]

FWIW, I put a square rubbermaid tub inbetween my flask and stirplate. Its filled with water and I heat the water with a fish tank heater and heat the flask like with a double boiler. Simple, no cracking issues or hot spots.

I don't boil inside the flasks, just maintain optimum yeast temperatures.

Cheers,
Brewer Pete

 

[Leigh]

Even with boro-silicate (which ours are) I wouldn't recommend using a hot plate.
A gas flame is fine though.

Cheers Ross

A flat hotplate is what they are designed to be heated with...I wouldn't be using a coil hotplate seen on some stove tops though...you would create alternating hot and cold spots that would expand at different rates!

 

[jonocarroll]

A flat hotplate is what they are designed to be heated with...I wouldn't be using a coil hotplate seen on some stove tops though...you would create alternating hot and cold spots that would expand at different rates!

That's just plain wrong, right? :blink:

The point of using borosilicate is that the coefficient of thermal expansion is so low (3.3ppm/K compared to about 9ppm/K for normal glass) - you can take it from stove to cooling liquid without it shattering. I doubt the hot/cold spots are going to differ by 100*C, even if it was some sort of crazy insane heat conduction.

Sorry - I hate people making claims without any science. <_<

 

[WitWonder]

I know you're supposed to be able to go straight from stovetop to water but I've not been game enough to do it with my flask, yet :unsure: . I usually let it cool a bit before dumping it into cold water.

I have the Simax brand and it's been fine (well, until I smashed it on the side of my boiler that is)

 

[therook]

That's just plain wrong, right? :blink:

The point of using borosilicate is that the coefficient of thermal expansion is so low (3.3ppm/K compared to about 9ppm/K for normal glass) - you can take it from stove to cooling liquid without it shattering. I doubt the hot/cold spots are going to differ by 100*C, even if it was some sort of crazy insane heat conduction.

Sorry - I hate people making claims without any science. <_<

Then why did mine break ?

Rook

 

[jonocarroll]

Then why did mine break ?

Probably some reason other than thermal shock of clean, in-tact borosilicate?

i.e. wasn't clean, wasn't in-tact (scratched or otherwise weakened), wasn't borosilicate, wasn't thermal shock?

On your answer above though - how do you spill something on the hotplate between the flask and the hotplate when the flask is on the hotplate??? Also, how does spilling something on a hotplate make a superheated spot? Changing a liquid to a gas (boiling it) uses up energy!

A better explanation might be you had some contaminant on the base of the flask that was able to absorb extra heat, causing a large, highly localised temperature differential.

 

[therook]

Probably some reason other than thermal shock of clean, in-tact borosilicate?

i.e. wasn't clean, wasn't in-tact (scratched or otherwise weakened), wasn't borosilicate, wasn't thermal shock?

On your answer above though - how do you spill something on the hotplate between the flask and the hotplate when the flask is on the hotplate??? Also, how does spilling something on a hotplate make a superheated spot? Changing a liquid to a gas (boiling it) uses up energy!

A better explanation might be you had some contaminant on the base of the flask that was able to absorb extra heat, causing a large, highly localised temperature differential.

I know you like to bag everyone and think your always right so this will be my last response

Liquid could have and was there from when the missus wiped the hotplates down 5 minutes before i used the flask and the flask was very clean to start with.

also Leigh has high credentials in this area

EOS

Rook

 

[Leigh]

That's just plain wrong, right? :blink:

The point of using borosilicate is that the coefficient of thermal expansion is so low (3.3ppm/K compared to about 9ppm/K for normal glass) - you can take it from stove to cooling liquid without it shattering. I doubt the hot/cold spots are going to differ by 100*C, even if it was some sort of crazy insane heat conduction.

Sorry - I hate people making claims without any science. <_<

Bloody physicists you are right there QB...temporary brain fade (or chemists fade ) on the coil thing.

Rook, go back to my first post (I stand by that), although it would need to be pooled water trapped underneath, not just a moist surface (that would evaprate rather quickly).

 

[therook]

Bloody physicists you are right there QB...temporary brain fade (or chemists fade ) on the coil thing.

Rook, go back to my first post, although it would need to be pooled water trapped underneath, not just a moist surface (that would evaprate rather quickly).

I hear you Leigh, but i deff had water trapped underneath

Rook

 

[Leigh]

Done that a few times myself...stick the flask on the hotplate, water underneath...pffffs ching "bugger!"