How do I know f I can use this flask to boil starter?

[Lando]

I picked up a flask today for making starters and there are no markings on it other than volume measurments up to 2liters. It is obviously some kind of glass. Is there anyway to tell if this is OK to go from the stove to sink without shattering other that to do it? I thought all flasks were up to the task, but now not so sure.

 

[mightynintendo]

I assume you have something like this.

These are made to withstand fast temperature changes so you can put it on your stove and then chill it without fear of it breaking. The problem is that they don't cool off very quickly as their shape encourages heat retention. You're better off using a pot for boiling the starter wort and then transferring it to the beaker once cooled off.

 

[Lando]

Yes, it looks like that, but there are no other markings saying it is pyrex or anything like that. Still good to go?

 

[mightynintendo]

My best guess is yes.

 

[GLoBaLReBeL]

I made the mistake of boiling my starter in the beaker and then adding the stirr-ing stone with only 30 seconds left to go . . . .

Lets just say it was like the first time I had sex . . . ended way to fast and I was left with a mess after!

 

[drac0]

Not too sure why you say they don't cool off fast.
I can take my flask from the stove, put it in an ice cream bucket on top of my stirplate, fill the bucket with ice, turn on the stirplate and have nearly ice cold wort in minutes. It takes me longer to cool the same amount of wort in a stainless steel pot in an ice bath.

Now, any glass container will retain heat longer than a metal pot, but I don't get much use of my magnetic stirbar in a stainless steel pot!

if the glass isn't borosilicate glass, you'll know the first time you try to rapidly cool it.

 

[GilaMinumBeer]

If it cracks, you weren't supposed to.

 

[drac0]

Post a photo. Maybe someone will know.

 

[shortyjacobs]

NO markings other than volume gradations? Are you sure? Maybe it says "Kimax", or has a picture of what looks like a gear? Any indentations/writing on the bottom?

 

[bad coffee]

Unless it says 'Pyrex' 'Kimax' or 'Bromax' or more specifically, "BOROSILLICATE GLASS" I wouldn't. Unless you want to waste a flask. It could be a spectacular mess though.

B

 

[BuzzCraft]

I assume you have something like this.

These are made to withstand fast temperature changes so you can put it on your stove and then chill it without fear of it breaking. The problem is that they don't cool off very quickly as their shape encourages heat retention. You're better off using a pot for boiling the starter wort and then transferring it to the beaker once cooled off.

you're right that they cool slower than metal, but unless you're in an awful hurry, it seems a minor drawback to boiling in the flask. you lose a significant sanitation advantage through the method you describe versus boiling in the flask and avoiding the transfer.

 

[BuzzCraft]

I made the mistake of boiling my starter in the beaker and then adding the stirr-ing stone with only 30 seconds left to go . . . .

Lets just say it was like the first time I had sex . . . ended way to fast and I was left with a mess after!

yeah, even if you drop your stir bar in there just after you pull it from the heat, you're in for a volcano!

what i do now is use another magnet on the outside of the flask to keep the stirbar inside the flask (but above the fluid) during the boil. you get the stirbar sanitized by the steam without the issue of it being a nucleation site. works great.

 

[shortyjacobs]

yeah, even if you drop your stir bar in there just after you pull it from the heat, you're in for a volcano!

what i do now is use another magnet on the outside of the flask to keep the stirbar inside the flask (but above the fluid) during the boil. you get the stirbar sanitized by the steam without the issue of it being a nucleation site. works great.

My stirbar just sits on the bottom of the flask while I boil...is there a problem doing it that way? Why keep it out of the liquid until after?

 

[springer]

My stirbar just sits on the bottom of the flask while I boil...is there a problem doing it that way? Why keep it out of the liquid until after?

I do the same they are teflon coated so boiling isn't a problem

 

[BuzzCraft]

yeah, i agree, no problem boiling them. but if i'm not using FermCapS, they cause serious boil over issues for me. i'm suspecting that's the mess one of the original posters was referring to, thus my suggestion.

are you guys able to boil with them sitting in your flask without some form of foam control agent?? i can't...my stir bar acts as a monster nucleation site.

 

[shortyjacobs]

yeah, i agree, no problem boiling them. but if i'm not using FermCapS, they cause serious boil over issues for me. i'm suspecting that's the mess one of the original posters was referring to, thus my suggestion.

are you guys able to boil with them sitting in your flask without some form of foam control agent?? i can't...my stir bar acts as a monster nucleation site.

Oh hell no, FermCap-S is my best friend with starters.....I see what you mean now, yeah, the bar acts as a major nucleation point, and it usually sits to one side, causing all the bubbles to stream up in a fountain along one side of the flask....I could see how that would be a real issue without the fermcap.

I usually boil 2000 mL wort in a 2000 mL flask, so without Fermcap I'm screwed, I think, regardless of whether or not the stir bar is in there.

 

[springer]

I also don't do a boil like I would do the wort. I just get it to a slight rolling boil turn the heat down and keep it around 190° . Always wondered why everyone say to boil for 10 minutes, I just do it to kill any bugs in there and 10-15 minutes at anything over 161° will do.