HYDRO FLASK - Travel Coffee Mug 177 ml (6 oz) - Vacuum Insulated Stainless Steel Travel Mug with Handle and Press-In Lid - BPA-Free - Black

Product Information

We dropped each flask five times from 90cm to mimic a dropped flask. Those with large dents that inhibited function or ability were rated low. We hand-washed each flask with hot soapy water and let them air dry overnight, then ranked them on smell. None of the flasks leaked from the main body – however, some flasks can't be filled to their stated capacity without liquid coming out when you screw on the lid.

Flasks are more 'smell prone' than 'stain prone' – none of the flasks we tested had any staining after cleaning, but some retained a faint coffee smell. Pay attention to details like leak-proof seals, insulation technology, comfortable grips, and easy-to-use lids. Textured coatings are useful – it’s a nice touch to have a handle on a drinks flask but generally, for a one-litre flask, it’s more useful to have a textured coating that provides grip. This does depend on factors like the flask's insulation technology, the size of the flask, the starting temperature of your coffee, and how frequently you open the flask. But typically, the best material for a flask is stainless steel due to its excellent durability qualities.Since the American manufacturer, Thermos, came to fame, the term has become slang for vacuum-insulated flasks. Although the terms are largely interchangeable, the original scientific phrasing is 'vacuum flask'. Jenna Bilbrey, BPA-Free Plastic Containers May Be Just as Hazardous, Scientific American, August 11, 2014 No consumer health risk from bisphenol A exposure, European Food Safety Authority, January 21, 2015 Look for flasks with excellent heat retention, sturdy materials like stainless steel, and are known to be long lasting.

All of which we have covered in our list of recommendations. Will coffee stay hot in a Hydro Flask? Jon Hamilton, Beyond BPA: Court Battle Reveals A Shift In Debate Over Plastic Safety, NPR, February 16, 2015 Jocelyn Ivanov, MIT, Drinking fountains: the past and future of free public water in the United States, September 29, 2015

Button-operated lids are more efficient to use than twist-and-pour stoppers – we found the button-operated lids to be more secure than the twist-and-pour stoppers.