Why You Should Think Twice Before Leaving Coffee Beans In A Hopper

There can be a lot of disagreement in the coffee brewing world over which brewing method is best, what roast or region yields the best flavor, and how to prepare different drinks. But there's one thing everyone can agree on — freshly ground coffee is always best. This is because the richest coffee flavors come from the oils released from the whole roasted beans, which aren't preserved long after they're ground (per Alternative Brewing).

All you need to grind fresh coffee beans is a small electric grinder, but if you're a hardcore coffee drinker, you may have a grinder with an attached hopper, or an espresso machine with a built-in grinder. You've likely seen these at coffee shops — the large plastic funnel-shaped machine that stores whole coffee beans, which are dispensed into the grinder and collected for either drip, pour-over coffee, or espresso. While it makes sense to store coffee beans in hoppers in coffee shops since they go through large amounts of fresh beans daily, it may not be the best idea for you to store them in your own home grinder.

Oxidized coffee beans

As Coffee For Less explains, the main purpose of a hopper on top of a coffee grinder is to make the grinding process more efficient and convenient, not to keep the coffee beans fresh. Storing your beans in a hopper can lead to them going stale for a few reasons. For one, coffee should be kept away from light, and hoppers are clear so you can see how much is in them.

Another reason hoppers can lead to your beans going stale is because they're not airtight containers. According to Roasting to Brewing, coffee beans need to be stored in sealed containers, or else they could begin to oxidize. If you keep old beans in your hopper for an excessively long period of time, the beans' oils could start to build up and create a film, which is not only gross but could damage your grinder and the flavor of the coffee. Ideally, you should only put the amount of beans you'll use within a day in your coffee grinder, returning the leftovers to an airtight container out of the sun at the end of the day. At most, you can keep them in the hopper for up to two days.