It works great I boiled in it I chilled in it there was no problem

Good quality glass! Makes an excellent starter!

This is what you need for your larger starters. It works well and can have hot wort cooled directly in ice water.

This flask is so much better than my last one. It's made from thick Pyrex and this guy is HUGE! Perfect for extra large starters for 10 gallon lagers. This is a bit overkill for 5 gallon batches but it's perfect for when you need to grow a ton of yeast.

Good addition to my flask collection, especially when doing larger starters.

I'm extremely happy with this 5000 ml flask. It it is of a high quality and I have no fear of it breaking without the exception of my own clumsiness. It is huge, beautiful and I got it at a very fair price.

This is for those BIG yeast starters and it works great!

I bought a 2000ml flask first, but wish I'd gone straight to the 5000. This one is big enough to make any starter you'll ever need and then some. In fact I've started doubling my starters so I can harvest half to keep yeast on hand for strains I use frequently. I boil directly in the flask on my glass top stove and transfer directly to an ice bath in the sink, no issues. If you do boil in the flask you'll need a few drops of fermcap-S to prevent boil overs

Excellent product for excellent price...

It works great I boiled in it I chilled in it there was no problem

Excellent! And thank you to the customer service team for awesome service!!

The size of this thing is mammoth. It is just what you need to for yeast starters for high alcohol brews. It would have gotten 5 stars but there are bubbles in the glass in certain areas, which means I have to boil the malt in a pot before transferring the hot liquid to the flask. I don't want it to shatter. Small inconvenience in my mind.

This is the Mac Daddy Flask. Big beer plans need a big starter. A gallon on the stir plate makes it happen. Discounted 1 star for the graduation marks at 4 & 5 liters being off by quite a bit.

For the price, this is an excellent 5-liter flask, just the thing for huge yeast starters. Be warned, though, that the volume graduations are not accurate, at least not on my model. The 2,000 mL mark is spot on, but others are not. I wouldn't discourage potential buyers from getting one of these if you just need a big, affordable vessel to contain a starter, but know that you can't trust the graduations on the side. Use a scale and you'll be fine, though.

I mean, it works great. When you want the flexibility to make starters of any size, just get a 5L.

Very useful and arrived as promised

Works as intended. Building up a starter right now. Great for 10 gallon batches

This arrived as advertised. A really big Erlenmeyer flask that seems to be very solid and well made, with uniformly thick walls and base. No scratches or defects found. Holds up to heating. And it came at a very good price for this size and quality of lab glassware.

Great for starters! Now I don’t have to be concerned with my yeast starters bubbling over and making a mess. Cooked right on the stove and then direct to cool water and ice with the borosilicate. Still works with my little stir plate as well.

Haven't had any issues using it stove top (electric). Recommended!

This is the largest flask I have ever seen! I filled it up to the 2L mark for my starter. Works on a stir plate and I'm not sure why so many people complained about the bottom. Mine starter stirred just fine. They pack this thing so well it's probably rare that it gets broken upon arrival.

Great flask for the price. I had a little trouble getting the stir bar to stay put. Ended up putting a plastic dinner plate on the stir plate; the increased height and/or extra plastic calmed things down. Made a healthy whirpool from 2L up to 4L, no problem, using 2in bar.

Everyone who brews 10+ gallon batches should own a 5L flask unless they want to buy a ton of yeast for each batch. I do not boil directly in mine. I recommend using it with a foam stopper for gas exchange and a couple drops of Fermcap to keep rowdy yeast in check. The bottom glass is slightly uneven so it can be finicky to get my stir bar going smoothly but that's to be expected with glassware of this grade. No complaints.

Excellent quality great price. However not wide mouth, makes pouring wort/yeast into it difficult. Flat bottom, works great for spinning magnets.

Would recommend this product. 5000ml Erlenmeyer flask.Good thick glass, perfect for my needs.

Works good. Didn’t explode when I boiled on stove and cooled in ice bath :)

I had a 5000ml flask I got off Amazon and could never keep the stirr bar going. This flas I can run the bar at any speed with no problem. Did a 3l starter with 2 giga packs worked great

Good quality glass! Makes an excellent starter!

The flask worked great for a 2.5L starter for a lager.The bottom is nice and flat so there were no problems with the stir bar on my stir plate. It is advertised as Borosilicate and able to withstand going from very hot to cold but it does not have any markings, such as Pyrex. I tried the double boiler method as mentioned in the info but after 30+ minutes the wort was not boiling so I emptied the wort into a kettle, boiled, then into the sanitized flask.

Excellent shipment, it arrived without a scratch, definitively the best size for my 1 bbl starters

Great 5L flask. This one has a very flat bottom so it still works with smaller stir plates such as the stir starter (what I have).

No issues with my stir plate. Stir bar holds tight in center of this flask at all speeds even though the bottom is slightly concave. A high quality stir plate with strong magnets may over come the drawback of a concave bottom. The graduation markings are "approximate." This isn't an issue for me because I use measuring vessels that are more accurate as a work around. This flask is priced appropriately for what you get, which is why I purchased it. My equipment was able to overcome the slight flaws easily, which made this flask usable for me and a bargain.