The Istituto of Espresso Italiano offers a specific description of “good” coffee: “The nose reveals an intense fragrance with notes of flowers, fruits, toast and chocolate… Its taste is round, substantial and velvety. Sour and bitter the tastes are well balanced and neither prevails over the other. There is little or no astringent taste.” In other words, you will to know good coffee when you drink it. According to Driftaway Coffee, your stainless steel mug might be the only thing standing between you and the coffee of your dreams.
If you’ve ever used a plastic travel mug, you know that the yellow coffee stain inside is a permanent fixture. This is because plastic absorbs flavors; it clings to that hot coffee taste and holds forever. Conversely, stainless steel does the opposite and transfers the flavors to the already existing profile. Likewise, stainless steel could fundamentally alter the chemical compounds that give a roast its unique flavor. According to CoffeeAndHealth.org, there are over 1,000.
Another reason a steel mug could ruin your brew is how it is made. In the same way that product processing and origin affects your coffee, metal mugs with lesser quality craftsmanship are often sealed with inferior finishes that excrete into your drink. When it’s time to invest in your next fresh cup of coffee, that extra twenty bucks might be worth the investment to avoid that metallic aftertaste.