21 oz Standard Mouth

21 oz Standard Mouth White
21 oz Standard Mouth Citron
21 oz Standard Mouth Tangelo
21 oz Standard Mouth Kiwi
21 oz Standard Mouth Mango
21 oz Standard Mouth Pacific
21 oz Standard Mouth Plum
21 oz Standard Mouth Forest
21 oz Standard Mouth Graphite
21 oz Standard Mouth Lava
21 oz Standard Mouth Cobalt
21 oz Standard Mouth Stainless
21 oz Standard Mouth Black
21 oz Standard Mouth Mint

21 oz Standard Mouth

Product Video
  • Loop Cap
    Loop Cap
  • Sport Cap - +$6.00
    Sport Cap

Works With:

Standard Mouth Sport Cap
Standard Mouth Sport Cap $9.95
Standard Mouth Loop Cap
Standard Mouth Loop Cap $3.95

Hydration on the Go.

Our 21 oz is the perfect go-anywhere companion on your busiest days. It stashes easily in a small shoulder bag, your pack’s side pocket or your car cup holder, and holds enough to keep you going for hours without weighing you down.

    Unique Product Benefits

  • Easy to Transport
  • Versatile, middle-of-the-road size
  • Universal Benefits

  • TempShieldTM Protected
  • Keeps cold up to 24 hours
  • Keeps hot up to 6 hours
  • 18/8 Pro Grade Stainless Steel
  • BPA-Free and Phthalate-Free
  • Durable, sweat-free powder coat finish (or our Classic Stainless option)
  • Lifetime Warranty
  • Compatible with Standard Loop Cap and Sport Cap
21 oz Standard Mouth is rated 4.7272727272727275 out of 5 by 44.
Rated 5 out of 5 by from Exceeds expectations! I was given a Hydro Flask a year ago and my immediate family slowly acquired a Hydro Flask for themselves. We all loved them so much that we got each family member for our reunion in Acadia National Park. Only regret is not enough colors in the larger jugs. I like "Matchy Matchy"
Date published: 2016-06-08
Rated 4 out of 5 by from Keeps my water icy cold but has one saddening flaw I love how well Hydro Flask keeps my water icy cold. It has a great look and feel to it. The one huge disappointment I just recently discovered from this amazing product is its durability. After only one fall from the kitchen table, my Hydro Flask has dented. It still holds water but I know with dents this will compromise its vacuum insulation and therefore lessen its capacity of keeping my water icy cold (plus its just sad to look at). Bottom line, I am so close to converting the whole family over to Hydro Flask but unfortunately, this tragic event was a rude awakening of its lack of durability (particularly with the item's higher ticket price compared to other water bottles).
Date published: 2015-10-03
Rated 5 out of 5 by from This was the size that sold me! This was the starter size for me that lead to my collection of all of the hydroflask sizes, except the 24oz (recently added, that's next).At first I bought this as a trial for my husband to take to work. He's a fuel truck driver on Oahu and the heat with humidity can make u sweat like crazy. He filled it up with half ice and water and he said it was wayyyyy better than the plastic frozen water bottles that he'd reuse all the time. Then he said he wanted a bigger size just for him. So I got him the 40oz n he said after 4 days it's not big enough so I got him the 62oz n he's been happy eversince. Me I had to get 32oz as the 21oz wasn't lasting me all day. But we still use the 21 when we gotta drive around alot as it's the only one that fits the standard size cup holder in our truck n we have the 64oz filled up ready to refill our 21. Bcuz of having access to ice cold water all the time. This product has helped us to lose weight alot and proud to say no more cotton mouth anymore. The reason I choose only this brand is their lifetime warranty, no one has this. I'll gladly pay the price for high quality and they keep their word too! I had 2 of my flasks returned using the warranty and had no problems since. As far as choosing btwn the stainless steel and the color. We ended up liking the one with color, the reason on is the heat. When u touch the stainless steel one and left iy in ur hot car, it's hot to touch but the ice is still there. When u do the same with the color one, its doesn't burn n there's grip to it. Like a sand kinda paint for it so it's not slippery like the stainless. My only little concern is having the larger sizes fit in the cup holder. But then again I understand the design would make it more expensive, besides other people makes holders, etc. so I can hang it from the neck part of my seat in my truck. Thank you Hydroflask for an awesome product. Sincerely, Da 808 couple!
Date published: 2015-08-02
Rated 5 out of 5 by from the BEST water bottle I have ever purchased I bought this a few months ago, and it comes everywhere with me. I cannot imagine using any other water bottle but this one. Cold water all day!!! And this particular size is great.
Date published: 2015-06-09
Rated 5 out of 5 by from My favorite water bottle ever! I bought one of these on a whim and I haven't stopped using it. I didn't abandon my other water bottles but I now use this as my main. In truth, I bring it with me almost everywhere now and it has actually helped me to become a more hydrated individual. The size is perfect and it fits right into the cup holder in my car. Water stays cool what seems like forever. The aesthetic of the sweat proof coating on the outside just seals the deal. I'm planning on buy one for each of my family members as future gifts.
Date published: 2015-09-21
Rated 5 out of 5 by from LOVE MY HYDRO FLASK!! I'm a teacher and lacrosse coach. I prefer to have ice available all day...quickest way to cool the body down. After a long hot day on the field and over a 48 hour period I had significant amounts of ice in my flask...with icy cold water to drink!! My current Hydro Flask was a gift, but I plan on purchasing several other items. P.S. My niece said I always have/ find great cool gadgets and technology. This is now the best, new thing I've ever had!! I use it everyday and I find I drink more water because it is icy cold. Thank You Hydro Flask & Thanks Kevin and Marissa for the Great Gift!
Date published: 2016-05-05
Rated 5 out of 5 by from I love my Hydro. I was given this as a gift, and it has been the best gift! One morning I made tea, and for some reason or another I didn't drink it in the morning. I was in my car and I looked down and saw that my hydro was in the cup holder. At that point I was sure my tea was cold, but I was thirsty. I took a sip and it was still hot! I was so pleasantly surprised! Ever since then, I carry my hydro everywhere. I have been trying to drink more water, and having my hydro has been the best thing for that goal. I love my ice water that will stay ice cold for the whole day! I am so about this product, I am looking into buying the 32oz and I know I won't be disappointed! #Godbless
Date published: 2016-04-08
Rated 4 out of 5 by from Not for trail use This bottle is GREAT for office use or delicate trail use. Fell out of my bag as I was picking it up and fell(less than 12 inches) now I have a pinky nail sized dent in the bottom. I love the bottle but I wish it was more durable. I would definitely recommend it for normal everyday use, just keep away from trail.
Date published: 2015-06-23
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Q & A

Can the Hydro Flask be used to store milk and/or protein shakes?

Asked by: Scott S
Yes! You can put anything in your Hydro Flask. Just be sure to give a little extra scrubbing afterwards!
Answered by: Hydro Flask Customer Team
Date published: 2016-08-17

Can I put carbonated beverages in the bottle without it exploding everytime I open it?

Asked by: Englishj59
Carbonated beverages are fine in any of our flasks. Just make sure to leave at least 1-2 inches of room from the top.
Answered by: Hydro Flask Customer Team
Date published: 2016-08-17

How tall is the 21 oz vs the 18 oz?

Asked by: DebraM
The dimensions on all of our products can be found in our FAQ. http://www.hydroflask.com/frequently-asked-questions/
Answered by: Hydro Flask Customer Team
Date published: 2016-08-17

will you make a straw lid that is compatible with the 21oz standard mouth? That would be the perfect hydro flask. I have not bought a hydro flask because this option is not available.

Asked by: Hene1113
We're not currently making a straw lid for the Standard Mouth Flasks. You could always try our Sports Cap!
Answered by: Hydro Flask Customer Team
Date published: 2016-08-15

Is it only water that can be used in the standard flask? Would it be safe to put apples and cinnamon in the flask?

Asked by: tbunch
You can put almost anything in your flask! However, if you do use something besides water, we would recommend a little extra cleaning afterwards!
Answered by: Hydro Flask Customer Team
Date published: 2016-08-15

Can your name be imprinted on the flask?

Asked by: Ron9016
We don't currently offer monogramming or name engraving, but any local trophy or engraving shop should be able to customize your flask for you.
Answered by: Hydro Flask Customer Team
Date published: 2016-08-11

Are lids included? The option to chose one when checking out makes me think other wise

Asked by: kaym
All flasks will include the lids pictured on the item being ordered. The additional lids listed are optional accessory lids for your ordering convenience.
Answered by: Hydro Flask Customer Team
Date published: 2016-08-11

what is the largest size to fit a golf cart beverage holder?

Asked by: dlite
24 oz or smaller will fit most standard cup holders.
Answered by: Hydro Flask Customer Team
Date published: 2016-08-10
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