Hydro Flask 32 oz Wide Mouth: The Insulation Claim, and the Cap That Voids It
The 32 oz Wide Mouth is $44.95 on Hydro Flask’s own site. The headline claim is 24 hours cold and 12 hours hot — but if you buy it with the Flex Chug Cap, the manufacturer tells you not to put hot liquid in it at all.
★ Verified at a glance
- $44.95 on hydroflask.com
- 32 oz · 11.00 in tall × 3.55 in diameter (Flex Cap) · 0.97 lb
- TempShield double-wall vacuum insulation
- Claimed: 24 hours cold, 12 hours hot
- Dishwasher safe · BPA-free · leakproof when closed
The cap decides what you can put in it
Hydro Flask sells this bottle with three cap options at the same $44.95: Flex Cap, Flex Chug Cap and Flex Straw Cap. They are not interchangeable in function.
The Flex Chug Cap version is explicitly not intended for use with hot liquids. So the SKU you buy determines whether the 12-hour hot claim applies to you at all. Nobody puts that on the front of the box.
Dimensions by cap
- Flex Cap: 11.00 in tall, 3.55 in diameter, 0.97 lb
- Flex Chug Cap: 10.20 in tall, 3.58 in diameter, 0.96 lb
- Both fit all Wide Mouth caps and lids
- Gram weights are not published — only pounds
On the insulation claim
24 hours cold and 12 hours hot is Hydro Flask’s own claim for its TempShield double-wall vacuum insulation. We found no independent lab measurement of it, and we have not measured it ourselves.
Real-world performance on any vacuum flask depends on how full it is, how much ice you started with, and how often you open it — a half-empty bottle opened every twenty minutes will not hit any manufacturer’s figure.
What Hydro Flask says not to do
- Not for use on a stove
- Not for use in a microwave
- Not for use in a freezer
- The Chug Cap version: no hot liquids
The steel grade question
Retailer listings describe the bottle as 18/8 pro-grade stainless steel. Hydro Flask’s own product page says stainless steel with TempShield insulation but does not state the grade there, so we are flagging 18/8 as a retailer claim rather than a manufacturer specification.
The warranty
Hydro Flask markets a “Hydro Flask Promise” and its FAQ page is titled “US Limited Lifetime Warranty Guidelines”. The body text of that page would not render for us, so we cannot state the term or its exclusions. Do not take “lifetime warranty” as read on the strength of a page title — check it before you rely on it.
A price correction while we are here: $49 was wrong, $44.95 is the current manufacturer price.
Sources: Hydro Flask: 32 oz Wide Mouth · Hydro Flask: 32 oz Wide Mouth with Flex Chug Cap
How this was checked: figures on this page were read from the sources linked above on 26 August 2026. We have not tested this product ourselves; where a figure is the maker’s claim rather than an independent measurement, we say so. Prices change — check the retailer before buying. See our Editorial Policy.
