The 21 oz vacuum insulated Hydro Flask is our most versatile medium sized water bottle and one of our most popular. With a convenient 21 oz capacity and a 1.81" mouth opening great for sports drinks, thicker liquids or nearly any size ice cube, this is a drinking bottle as diverse as you!
The 21 oz insulated bottle is made from 18/8 food-grade stainless steel and the double wall vacuum insulation provides top notch insulation power, keeping cold liquids icy cold for up to 24 hours and hot liquids steaming hot for up to 12 hours.
Hydro Flask is proud that all our products are BPA-free, 100% recyclable and are backed by a lifetime warranty. Look for the H-guy and Hydro Flask logo to ensure you’re getting the market’s premium insulating beverage bottle.
Posted by Marty Carl on 07/28/2014
I too need a better top. I love my bottle but what a pain to have to unscrew it every time I want a drink. Please come up with another option.
Posted by cassy on 07/18/2014
I noticed you can only look at 4 to 5 star ratings. There is a box that says look at all reviews but it will not show anything under 4. Please be aware, that it will not keep your water cold all day if you open it and drink from it more than 3 times. It is also very small. This causes issues immediately. I did try to keep water cold in it, but believe due to our country's temperature, it would not do a sufficient job, it did stay cool but not cold as it promises. It is fine for a few hours. I give it 3 out of 5.
Posted by Paul G on 07/02/2014
This bottle is great... keeping ice water cold (and ice unmelted) for even longer than advertised... I just wish lids other than the flat top one were available for the 21 oz model!
Posted by Paolo on 07/01/2014
Hydro Flask is best bottle I had ever purchased! It's a bit pricey here in the Philippines, but totally worth it! Hope you can officially have a store here.
Posted by JL on 06/17/2014
I filled this three-quarters water and the rest ice at 8am and left it in my car in the sun for 8 hours on a 90 degree day... The water was still ice cold at 5pm, 10pm, and the next morning. Thanks for making this! I am buying a few as gifts for my friends.
Posted by Cecile on 06/09/2014
Best water bottle I have ever had. Can sit open in a 75 minute hot yoga class and the contents stays cold.
Posted by Jan on 06/04/2014
Living in the desert, we've found our Hydro Flasks to be a gift of life as we can keep our water cold at all times in all places. We've been so impressed with the ones we bought for ourselves that we purchase an additional 15 for other family members who all love them. No matter where we go, people ask about and are interested in this amazing "bottle" that is able to keep our water cold even in the car when the temps reach 120 degrees. The water is always cold and refreshing which continues to be a "gift of life". We definitely need the SPORTS CAPS - we originally bought just a couple but everyone who sees ours wants one. PLEASE! PLEASE! Bring back the sports cap. Also, how about more colors? Navy blue!!! Oregon Duck Green!!! More masculine colors are needed.
Posted by CGodeski on 06/01/2014
We have one Hydro Flask and just ordered 3 more. We have a hard time keeping drinks cold in our boat, but the Hydro Flask works great. Drink stays cold all day.
Posted by Scarlett DB on 05/31/2014
This bottle is amazing! It delivers everything it promises. Keeps water cold for a whole day without condensation and is extremely sturdy. The only problem I have had with it is the black coating heats up in the sign and becomes painful to touch.
Posted by Daniel Mann on 05/09/2014
Upon purchasing my 21 oz 'Foliage Green' Hydro Flask, I got home and immediately filled it up with ice. Closed the lid and then left it there for over 12 hours (with no water, just ice). When I woke up the next morning, I opened it up and turned it upside-down over the sink to see how much ice had melted overnight... AND NOT ONE DROP OF WATER FELL FROM THE BOTTLE! I was a little skeptical of the product and the pricing, but now am sold 100%. Even got one in 'Everest Blue' for my wife and we never leave home without our Hydro Flasks!
Posted by Chuck Frazier on 05/03/2014
Great product but need a straw top for the standard top bottle.
Posted by Sam on 05/02/2014
Probably one of the best purchases I've ever made. It's worth the price. I use the flask everyday with water. I'm a bit sick today so I put some tea inside. The tea has been in there for 4 hours now and is still very hot. Quite amazing. I highly recommend purchasing one. The 21oz is a very good size for everyday use.
Posted by Kristina on 04/29/2014
All of the reviews on here are correct. This flask keeps drinks cold all day long. I noticed it kept them cold even with the top off. I like to have a flavored carbonated water at my desk and it tastes terrible room temperature. This thing keeps it cold all day long. Definitely worth the money.
Posted by Chris B on 04/22/2014
I bought the 21 oz and the 40 oz a couple days ago, totally impressed , it held ice and cold water for over 30 hours with absolutely zero/no/ none/nada condensation. I live in Tucson area which is in the high desert valley and it does get hot here, The hydro Flask is a great product, I bought another 21 oz today and plan on getting a couple more 40oz when the local store gets more in... remember to hydrate > drink half your body weight in fluid oz (water) everyday no matter where you live
Posted by Caitlin Parker on 04/18/2014
This water bottle was gifted to me, and has been heaven sent as I live in Maui where the sun always shines, and i'd just gotten used to drinking warm water all the time! It's the perfect size, and keeps your drink the temperature you put it in at for many hours! Awesome!
Posted by sheepdog on 04/03/2014
I love this bottle. I got mine from goodwill for $0.50 cents. Keeps warm stuff warm and cold stuff cold. I work in the ice cream department at a distribution center where the temp is -14F. It's nice to have a warm cup of coffee between breaks.
Posted by Jack on 03/15/2014
The Hydro Flask insulated water bottles is the best bottle I have ever used. It keeps my water cold and ice cubes last for well over 8 hours and zero condensation. The mouth is wide enough for ice cubes so I don't have to force them and the smooth edges on the mouth are comfortable to drink from. Some people have complained about a metal taste but I haven't noticed it unlike some of the other bottles that I have used in the past. I also like the coating. I wish there was a flip cap that I could buy though instead of having to unscrew and screw it each time I take a drink but honestly i can live with it like it is.
Posted by Arnold Milstein on 03/13/2014
These are great bottles! I have three plus one 64 oz. I only bought one sports top with my first order, now I want two more. I know they are being redesigned, but how long does that take? Let us have the old style it is better than nothing.
Posted by Disappointed on 03/06/2014
My well meaning hubby bought the very large 40 oz bottle and it was way too big for my grip. The people he bought it from wouldn't give him a refund, but let him exchange it for this 21 oz size. I was a little disappointed because there was no pop top to drink from like my Thermos, but no biggie until I drank from it and got that metal taste with my gulp of water. Needless to say that it will be shelved with our other unusable water bottles in the water bottle graveyard under the sink.
Posted by Ajjimenz on 03/01/2014
I bought a hydro flask during the summer at UC Berkeley. I drank a lot of water because of all the hiking and it was hot mid day to like 5. This is the best water bottle I've had in my 15 years of existence.
Posted by Jeff on 02/27/2014
I bought mine in Hawaii recently and love it. It doesn't sweat so the sand didn't stick to it. It kept my water cold even after hours sitting on the beach in the sun. Loved it so much I bought a 40 oz water bottle as well. Would highly recommend any of the products.
Posted by Katy on 02/20/2014
Thank you so much. I bought my water bottle at REI and was immediately in love with it. My husband is now in love too. The lid broke. I emailed them. A new one arrived a week later! Thank you so much.
Posted by Alex on 01/08/2014
Nice bottle. But I could scratch off the paint around the mouth. So I worry that the coating can get into my mouth when I drink the water.
Posted by Sandy Hoveskeland on 12/19/2013
Are these ever coming in? They have been out of stock FOREVER!!!!!!
Posted by Serena W on 12/12/2013
It is the best water bottle ever!!!!! It really keeps drinks cold. When I go hiking, I put ice in the bottle and it doesn't melt at all!!!
Posted by Justin on 12/05/2013
This flask was a huge rip off. I put coffee in it and it stays WARM for about an hour. I can feel the outside of the bottle getting hot when I pour it in. No way it even comes close to the 12 hour claim.
Posted by Channing on 12/03/2013
Great water bottle, I use it daily to keep my drink cold all day, but I have been waiting months for the other lid to come back into stock and still waiting... Why so long of a wait?
Posted by Annette on 11/29/2013
I cannot say enough great things about this bottle. I bought this bottle (Everest Blue) about 2 months ago and absolutely love it. I work 12h shifts, and if I don't have a chance to drink my water until late in the day, no room temp water or yucky taste!--Fresh as when I poured it. My daughter wanted to take it to school, and I told her NO WAY!! It is mine. Looks like I'm going to have to get her one too. I rarely leave the house without it. I may ask for another for hot liquids though, b/c it takes a very long time for hot liquids to reach a drinkable temperature. Perfect size for car too, even fits in door holder.
Posted by Theresa Monroe on 11/11/2013
I love my water bottles. However, if you don't get the lids in soon, I will be forced to throw them all in the trash and find a different brand. I am sick of going to the site to no avail. This stupid lid has been on back order for months. What gives??????????????????????????
Posted by Una Nelson-White on 04/29/2013
21 oz standard mouth bottle w/ sports cap is perfect fit for regular bicycle water bottle holder on bikes. I love the fact it keeps water cold on long hot rides, unlike any other water bottles out there including the so called insulated one with a bear on it. My food coop carries the larger size but I am going to ask them to carry this size for all the bike riders who use the coop.
Posted by Dana A. on 12/03/2012
Received my 21 oz flask/bottle for Christmas 2011. I've taken it up 12 or Colorado's 14,000' mountains this year. Kept my drinks cold during the summer, and kept my hot drinks hot for 12 10-12 hours this fall. Taken a couple tumbles on the peaks, minor paint chipping and dents.
Posted by Lindsey on 10/21/2012
As an outdoor professional in Hawaii, I have struggled to find a water bottle that suits my lifestyle and will keep my water cold...until now! I have the 21oz standard and it's perfect! I will be getting more!!!
Posted by Peter on 06/24/2012
Got the 21 oz. standard mouth Hydroflask 6 months ago, it's great for hot tea or cocoa when you're snowshoeing, hiking or skiing in winter, a solid pick-me-up when you need a quick warm up to re-energize, keeps drinks hot for a solid 8+ hours outdoors. Now that its summer, I was amazed how cold it keeps drinks, without the ice cubes melting, a real treat to cool off with after a long hot trail run. No problems at all with the black coating, looks like new after a lot of hot and cold weather use and long road trips.
Posted by Lillian on 06/15/2012
This bottle has gone with me everywhere for the last two years. Keeps my fluid cold for ever. I was driving my motorcycle and my bottle fell, I went to get it and was Not damage(only the paint a little). I Really LOVE it!!! The price it's worth it.
Posted by HR on 02/14/2012
No bad things really.... This bottle has gone with me everywhere. I love it. Keeps my water cold for ever. I love to amaze my friends by pulling it out of a hot car or after a long hike and say ha! I have refreshing delicious-ness.
Posted by Nic on 01/31/2012
I never thought I'd spend this much on a bottle, but it's worth it. I work outside through every season and this has yet to disappoint me. It keeps my drink warm/hot even when spending hours in below freezing temps.
Posted by Ty on 01/12/2012
This is a great bottle. Keeps cold things cold and hot things hot, but...the top comes apart. The thread section comes apart from the section with the carabiner and makes it difficult to open. (You may notice they are selling replacement tops in the accessories section.) Also, as mentioned in other reviews the paint does chip some. Overall, good water bottle. Just fix the top design.
Posted by Valerie on 10/06/2011
I have to say I have NEVER had a water bottle this good. My ice stays ice all day and night. You will not be disappointed. Best investment I have made.
Posted by Steve on 07/15/2011
Yes, it lives up to the hype. I ordered a 21oz standard mouth, orange, for a recent trip we were taking. This thing is made exceptionally well. It was also able to keep ice\water cold, real cold, for full days in the 95+ degree weather. I'll be ordering another for an upcoming trip, so we don't have to refill as often. 8-) Note: The standard mouth is a great size for standard size ice cubes. I was worried it would be too large for comfortable drinking, but it is perfect!
Posted by Chris on 05/28/2011
Bought the 21 oz Orange at the Saturday Market in Portland on a recent trip and absolutely love it! I haven't had any issues with the paint chipping. Can't wait to get / try the beer growler!
Posted by JD Scott on 05/26/2011
Living in the desert, I have tried various water bottles and none have kept anything cold for very long until the Hydro Flask. It is without a doubt the best I've used. I'll be getting more for the family soon!
Posted by Amby on 05/15/2011
this product is awesome, a little pricy, but considering how much other wate bottles are it's a good deal!
Posted by Craig F on 11/20/2010
Dimensions (not official but according to my tape measure)-- 24 oz. flask: 7.5cm in diameter at base, 3.5cm/diameter internal mouth opening, 27cm height (without cap), 30.5cm with cap. Excellent product, it does keep the ice frozen in water for hours--8hrs, 6 cubes (Conditions: Classroom Teacher). Haven't tried any hot liquids yet. There is no "bottle sweat" or thermal leak to the outside layer of metal. P.S.--The company gives 5% of your purchase price to a charity of your choosing.
Posted by S. Cheng "mrwaste" (Santa Fe, NM) on 11/20/2010
I bought it to replace a cheap one I bought from WalMart. The difference is night and day, even it is much more expensive. The flask is well built with study stainless steel. I like to put the ice water in it. For over 24 hours, it is still cold. It is exactly what is advertised.
Posted by Shlompsen on 11/20/2010
This is a very nice bottle from a good company. I prefer it to the Sigg bottle I had before because of the insulation and the absence of weird chemicals on the inside. The threads between the bottle and the cap are not as well toleranced as the Sigg bottles, but the seal is very good and it never leaks. The main problem I have is that the paint on the outside of the bottle rubs off very easily and it gets all over the other things in my bag, including my computer and my books. So if they could re-engineer the paint and maybe tighten up the tolerance in the screw threads, it would be a perfect bottle. But, as it is, it is still my favorite water bottle.
Posted by F. Jasman (Greenville, SC) on 11/20/2010
This is the third HydroFlask water bottle I've bought. I've only used them for cold liquids, and they really keep liquids cold. I used to take a Tervis tumber with me to work (with ice inside), but since discovering these, they are now what I take with me. They keep ice longer and liquids colder longer than the Tervice tumblers, and are much sturdier. I just wish Amazom carried the caps too, because the HydroFlask sports caps are a very nice accessory to have. Highly recommend any water bottle by HydroFlask, a great product all around.
Posted by Jonathan Manili (Nicaragua) on 11/20/2010
Works well with hot and cold. I have the evergreen, nice color but the paint starts to chip quickly. Not big chunks but it's noticeable.