3000ml Narrow Mouth Erlenmeyer Flask, 3.3 Borosilicate Glass, Karter Scientific 213G16 (Single)

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.

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 purchased the case of 4. One cracked on the second use. No cold shock involved. Simply heating water over flame, as per intended use. I would strongly advise against heating using this flask, since you risk having 5 liters spilling all over your work area. The second issue is less significant, but puzzling. One of the 4 flasks had a neck opening diameter significantly smaller than the others, such that it required a different sized stopper. Very strange to see that level of dis-uniformity in something that I presume comes off an assembly line.

The packing job on these for shipping was incredible each individual one was bubble wrap and then double boxed I ordered to they came in another box. I was just blown away by the work they did on that. The mouth to these Erlenmeyer flask is so large and makes getting stuff in there really easy. I am super happy with the purchase. These are way nicer than my other Erlenmeyer flask

I wanted to upgrade to a larger, 3L flask for making larger yeast starters for home brewing. The flask arrived in fair condition, unbroken. However, with numerous scratches and a couple bubbles in the glass, I'm going to assume that these flasks are factory culls from China, sold at discount prices.I tested the flask with some water on my stir plate and found that the raised shape of the bottom prevented the spin bar from staying in place. It took only a few seconds before the spin bar was thrown to the side. Regardless of what speed I set the stir plate, the bar would quickly fling off the center. That makes it unusable for use on a stir plate.The flask is being relegated to other tasks, such as mixing ingredients. But due to all the scratches and bubbles, I am hesitant to attempt heating anything in it. I really don't want to be showered with glass shards. In the end, a rather expensive bottle. I will spend the extra $$$ and buy Pyrex or Kimax brand in the future.

Item arrived with cracks and bubbles in the glass. There were also a strange series of brown rings "rubbed" into the surface of the flask that would not wash off. I can deal with the bubbles, and maybe the rings, but the cracks I cannot. I needed the flask for a project and will now have to make due some other way.I have several other Karter Scientific flasks, all of which suffer from bubbles in the glass. Not a big deal to me since I am not applying direct heat, but might matter for others.I am returning the item and may try to order another one, we shall see.

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.

This Erlenmeyer flask is made of borosilicate glass but is NOT flat-bottomed as advertised. I bought it for making yeast starters for beer brewing, but the arched bottom won't allow the stir rod to stay in place...it slides off to the side of the flask, making it impossible to use with a stir plate.Other than the falsely-advertised feature, it has been an excellent flask, nice and durable, too.

Arrived well packed in good shape. Should work well, very satisfied with all other Karter I’ve bought, this is same. Thanks

Broke after 2 use, and I'm not rough. It is suppose to resist heating on a gaz oven, but it doesn't. Imagine a boiling 5L beer starter on your kitchen floor. Now imagine your girlfriend when she see you in a cold bath to treat your second degree burn, while the kitchen is soaking in sticky beer.Enough said

So much easier to use this than several smaller ones

Bubbles in the glass so heating is a bad idea and the bottom is convex making it useless on a stir plate. I was planning on using it for yeast starters but it fails in all regards

Domed bottom. Does not work well with stir plate.Seems to be good quality. Withstood boiling and cooling in ice without cracking.