5000ml Flask, Narrow Mouth Erlenmeyer, Borosilicate 3.3 Glass, Karter Scientific 213G17 (Single)

There were visible bubbles in the glass in this product. I wanted to use it for yeast starters in my homebrew setup where I would be boiling water and sugar inside it then rapidly cooling it before pitching yeast. I returned the product because I was concerned thermal shock would be an issue. I'm not guaranteeing this product would break, but be aware of this possibility if you intend to heat and cool it rapidly or often. There is a reason that lab grade glass is expensive.You can buy Pyrex lab glassware in this size in orders as small as 4x pieces, so I recommend going in on the real lab grade stuff with some buddies if you want a durable product that lasts.

I just received this item so I cannot say yet how the glass holds up but I just had to give them props for their excellent packaging! This thing is huge and as you can see in my photos I took that it came in 3 boxes! Each box had packing stuffed around it. Thanks so much for this! I was afraid it would come cracked but it held up well!As for the glass I'm not an expert. I just bought this for my son’s science project. He’s making elephant toothpaste and we found out that this shape glass is the best to use. There will be some heat involved after he mixes his ingredients together so hopefully it will not crack and will hold up.I tried to take several pics of the glass and as you can see on the bottom it appears to be quite flat. There are some white circle spots on the bottom, not sure what that is and the yellow speck is something the glass picked up off my couch lol.

I have not used this to boil starter wort in like many reviewers have dinged this flask with but I can't imagine it would be a problem. Mainly use this for a starter vessel poured from another pot. I use this with the same smaller stirplate and stirbar that I used a 2 liter starter I already had with NO PROBLEM! (this was a concern prior to using this)It's simple. Just treat it carefully and gently like a large glass flask (that it is) and you won't shatter it like some reviewers have.

Broke during boil the 2nd time used. 4L starter all over my gas burners. Flooded my stove and shorted out something! Garbage! How is anything getting done in China(and the rest of the world) when they produce such crap. It's like the world forgot how to make things just so they could sell more of them.

Keep in mind this flask is huge. It probably wont fit in your fridge without moving the shelves a bit higher. I use it for 4 liter yeast starters with a 2 inch neodymium stir bar when brewing lagers and still have plenty of head space. The only issue I have, and this will happen with all flasks this large, is the bottom may not be completely flat. But its close enough. When using a stir bar, you have to move the flask around a bit to find that flat "sweet spot" that doesn't cause the stir bar to rattle. The one on my flask is slightly off center which is not a big deal.

Works as advertised. This allows me to make a four liter starter in a single container.

Works as it should for yeast starters used in home brewing.

I used this for my yeast starters for 1/2 BBl batches. Requires a larger stopper if you use a bubbler. I would recommend this for purchase.