NERD ALERT: The following is an explanation of the chemical properties of our beloved Hydro Flasks®. If it’s enough for you just to know that they’re the best reusable drinking bottle you’ll ever own, then you’re dismissed. If you need more scientific proof to convince you, then read on!
At Hydro Flask®, all of our bottles are manufactured using 18/8 stainless steel. So what the heck does 18/8 mean? It indicates the quality of the stainless steel and refers specifically to the percentages of chromium (18%) and nickel (8%) added to provide the anti-rust/staining properties that carbon steel lacks on its own.
There are different grades of stainless steel available, with the numbers denoting their quality. Higher numbers indicate more corrosion-resisting properties, while lower numbers denote the inferior characteristics that lead to the aforementioned staining.
At the lower end, steel must contain at least 10.5% chromium to be called stainless. 18% chromium is the standard for top grade when used in flatware or cutlery, so almost all high-quality flatware has an 18/8 composition and is dubbed “food grade.” Chromium adds hardness and brightness to stainless steel, making it the source of the metal’s shine, and nickel is added to prevent corrosion by enhancing the surface layer that chromium creates.
18/8 stainless steel is the preferred material wherever food or beverages are concerned because it does not affect flavor, either by adding any metallic taste of its own, or by retaining any flavor from the previous foodstuffs with which it came into contact. This is a function of the combination of chromium and nickel, which creates a non-porous surface that inhibits the growth of bacteria. Bacteria, which are the cause of odors, like to cling to porous surfaces where they can thrive. At the first sign of soapy water, any bacteria that have dried onto the surface of 18/8 stainless steel are swept cleanly away.
Hydro Flasks® benefit from all of the superb qualities of 18/8 stainless steel, so you’ll never have to worry that the hot coffee you took for your late-night lab session will stain your bottle or ruin the taste of your ice cold milk the next day.