Ecnerwal <MyName...@ReplaceWithMyVices.Com.invalid> wrote:
> baloonon <
balo...@hotmail.com> wrote:
>
>> Funny thing, I was just googlin' around a bit to try to get a
>> sense of what is a smart cushion of temperature difference for
>> avoiding thermal shock and cracking regular glass. Does anyone
>> have a good safe limit?
>>
>> In other words, if my mason jar is 72F, adding liquid that is
>> 73F isn't going to be a problem, but adding boiling liquid
>> (150 degrees hotter than the jar) may cause a horrible break.
>> What's a good safe upper
>> limit? +50 degrees? +75 degrees? Something else?
>
> A good limit is "get thyself a chiller" so you are not putting
> hot stuff in a carboy.
I use a chiller for big batches of wort, but they're not much good for
cooling a liter or two of boiled DME for starter, which is what I pour
into jars.
I'd love to be able to pour near-boiling starter mix into a jar or two
to let it cool so I can clean the pot and be done with the kitchen for a
while, but I'm always a bit wary of pouring superhot liquid into room
temp jars. There's always the ice bath option for the boiling hot pot,
but often someone forgets to refill the ice cube tray, and I'd prefer
not to waste the water for a plain water bath, plus this time of year
the cold water coming out of the tap isn't very cold.
> Mason jars may or not be the same as "regular glass" though I'm not
> terribly convinced that they are Pyrex (borosilicate, to be
> non-brand-specific) really, so they are probably fairly close to
> regular glass if they are any different.
I think the safe assumption is that they're regular glass. Like I said,
I'm sure they're fine for liquid one degree hotter than the glass, and
it's dicey for liquid 150 degrees hotter. Somewhere in that +1 to +150
range is the sensible upper limit for how hot the starter wort can be
when you pour it into the jar, but I'm not sure what that would be.