Word to the wise... Don't freeze wort in your borosilicate flask

[Jayjay1976]

You must be really bored if you're digging up six year old threads...
Personally, I wouldn't freeze any liquid in a container that is not made of flexible plastic and has a cylindrical shape that allows for plenty of expansion. Even the most expensive labware will crack if subjected to the pressure of expanding ice.

Haha, you got me. This thread showed up at the bottom of the screen under "Similar threads" so I read it and thought I should contribute what information I have for posterity. This thread may be old but it ain't dead, and the information contained is still relevant, applicable and useful for new site members.

I might add that although my comments weren't exactly aligned with the thread title, they were tangential to some of the most recent discussion about safety when boiling starters in borosilicate flasks.

 

[IslandLizard]

You must be really bored if you're digging up six year old threads...

I'm quite sure the Similar Threads list on the bottom of each thread page brought this on.

Look at the first item in the list on this page:
https://www.homebrewtalk.com/threads/freeze-your-wort.684712/#post-8978314It sends you here!

 

[passedpawn]

I have some experience in glass manufacturing, there are several grades of borosilicate. The higher the grade, the lower the coefficient of thermal expansion. The boro material itself can also vary from batch to batch, both in composition and in final quality. This is why some brands cost more than others; higher purity raw materials, precision batch mixing, melt quality control, as well as scrapping or reprocessing rejected lots of ware or batches of glass. Its also why there is a lot of "student grade" glassware on the market, they don't meet first-quality lab grade standards and it makes more sense financially to sell it as such rather than scrap it.

The top-grade stuff is really expensive but it is also nearly immune to thermal downshock. When it comes to glassware, you really do get what you pay for. Word to the wise, avoid generics or bargains and buy name brand glass from a lab supply. I cringe every time I walk past the $50 no-name flasks sold at my LHBS. I like Pyrex but Carter would be my second choice.

Thermal shock has to do with expansion of the glass at different temperatures. That's not what killed the flask in the OP. That was due to the water expanding 9% at freezing. Unless your fancy borosilicate can stretch, it's not going to matter

Materials get more dense as they get colder. If it wasn't for this phenomenon, water suddenly getting less dense near its freezing point, there would be no life on earth as the lakes would have frozen from the bottom up, killing most life in them.

[edit] ... and now I see I'm beating a dead horse here.

 

[Jayjay1976]

Thermal shock has to do with expansion of the glass at different temperatures. That's not what killed the flask in the OP. That was due to the water expanding 9% at freezing. Unless your fancy borosilicate can stretch, it's not going to matter

Materials get more dense as they get colder. If it wasn't for this phenomenon, water suddenly getting less dense near its freezing point, there would be no life on earth as the lakes would have frozen from the bottom up, killing most life in them.

[edit] ... and now I see I'm beating a dead horse here.