United Scientific™ FG4980-5000, 5000mL (5L) Borosilicate Glass Erlenmeyer Flask (Single)

Purchased this after my kids accidentally broke my last one. Works great for making yeast starters.

Exactly as advertised. Excellent quality and just the right size needed for larger yeast starter cultures.

The flask looks awesome and is a giant beast, very large volume, however... It's either not tempered glass or is not stringently manufacturered to withstand a wide range of fluctuation in temperature. I used mine about 5 or 6 times making DMT and it burst during the first phase of the last batch I started, spilling the all the contents all over the work bench, with the last of my mimosa MHRB leaving a deep, dark red hue stained into everything it touched or soaked into. I had it on high heat on a stand alone electric burner and within about 15mns it just popped at the bottom separating into 2 pcs with a big crescent-moon shaped pce splitting off of it and it was no bueno. I did the first few batches with the flask inside a pot of water to heat the mixture to test it's integrity and it was fine with being quite hot and then being rapidly subjected to colder temps from water being poured into or over the exterior with no signs of expansion & contraction, so I eventually decided to go straight to direct contact with the burner and it worked fine like that for about 5 or 6 runs. But that last one did it in and thank God it wasn't later into the extraction process with the solvent in the flask cuz it most likely would have ended in a decent size fire erupting instantly, which if we couldn't put out on our own and had to call EMS to help... Well - that woulda just been all bad, nothin but the poops, babe. So yeah - if you need a flask for mixing large volumes of stuff that's not flammable or that doesn't need to be heated, this will do fine I think. But for shit that can lead to felony charges, I would not rely on this thing. Spend more if that's the case. Because you will wish you had if you end up sitting in booking down in county with your clothes and eyebrows half scorched as they fingerprint you. Be safe.

I purchased two of these 5000 ml flasks. What I received was not a Bomex (as pictured) or a United FG4980 (as advertised). These are either knock offs or factory seconds as both had defects/flaws (bubbles). 1 bubble in the first flask and 3 in the second flask. BUT they are flat bottomed - so we know they are not Karter brand flasks (these have a punted bottom that makes them VERY difficult to use with a stir plate). For the price with shipping being $20.00 less than real United brand flasks and the fact that I am not using them with direct heat I will keep them. Please be careful if you attempt to use a bubbled flask on direct heat. They will fracture.

DO NOT BUY. Passed off a cheaply made thin-walled flask at a more lab-grade price. I specifically paid more for what I thought would be a more sturdy lab-grade flask comparable to Pyrex knowing these larger flasks need to have more structural integrity. Instead, I got a flask that has no thicker walls than my 2L flasks. This is a terrible design flaw on top of what is probably poorly formulated borosilicate glass imported from India(what it said on the glass). The flask I received did not handle even slight temperature fluctuations within the range of what borosilicate glass should be capable of handling. Cracked on the very first washing. Returning.

Perfect. No complaints. This thing is HUGE and works perfectly for my elephant toothpaste experiment.

Bought this for my beer yeast starters. Have not had any issues with the flask. Went from hot to cold without issues. I would recommend this Flask. I make 10 Gal All Grain batches so wanted a larger Flask. Probably too large for a 5 gal starter.

Advertised as USA Country of Origin but clearly made in India. I'll see how it holds up under brewing/starter heat loads and handling.