Cleaning Your Water Tank, Drip Tray, and Grounds Bin

The water tank, drip tray, and grounds bin are the parts you pull out, dump, and slide back in without a second look. They're also where standing water and wet coffee sit long enough to get funky.

A few minutes a week keeps all three fresh, and keeps your coffee tasting like coffee instead of something left in the sink overnight. Here's what each one needs and how often.

Why These Parts Matter

All three hold moisture. The tank holds water that sits at room temperature between uses, the drip tray collects coffee-tinted water and stray grounds, and the grounds bin is packed with damp, used coffee. Given enough time, any of them will grow mold, film, and sour smells.

There's a practical side, too. A neglected drip tray overflows onto your counter, and a tank with film on the walls is sitting right at the start of every drink you make.

The Water Tank

Start each day with fresh water rather than topping off whatever's left from yesterday. It's a small habit that keeps water from sitting in the tank for days at a time.

Once a week, empty the tank and wash it by hand with warm water and a little mild, unscented dish soap. A soft sponge or bottle brush reaches into the corners. Rinse until there's no soap smell left, since any residue ends up in your next shot. Skip abrasive scrubbers, which can scratch the plastic, and check your manual before putting the tank in a dishwasher, because not every tank is rated for it.

Leave descaler out of this job. Descaling is its own process run through the machine, and our descaling guide walks through it step by step.

Filters and the Tank Seat

Many tanks hold a water filter cartridge or an intake screen near the bottom. Pull the filter out before washing the tank, keep soap away from it, and give it a rinse with plain water before it goes back in.

Replace filter cartridges on the schedule your manual gives. Superautomatics often track this for you, and our superautomatic cleaning guide covers the brand-specific filters. Good filtration also slows scale buildup inside the machine, which our article on hard water explains in detail.

Wipe down the spot where the tank sits while it's out. Water drips there every time you lift the tank, and that ledge quietly collects dust and film.

The Drip Tray

Empty the drip tray every day you use the machine, and before it's full. Many trays have a float that pops up as a reminder, but making it part of your shutdown routine saves you from the dreaded overflow.

Wash the tray and grate with warm, soapy water a few times a week. Coffee water dries into a brown film in the corners, and grounds settle under the grate where they're easy to miss. Drainable drip trays sound like a shortcut, but the drain hose is one more thing that collects coffee residue and needs regular cleaning.

Our article on why water ends up in your drip tray explains where it all comes from and what's normal for your type of machine.

The Grounds Bin on Superautomatics

Superautomatics drop each used puck into an internal grounds bin, also called a dregs drawer or puck drawer. Empty it whenever the machine asks, and don't wait until it's packed solid.

Some machines count pucks and expect you to empty the bin while they're powered on, so the counter resets when the bin comes out. Emptying it with the power off can leave the machine thinking it's still full. Your manual will tell you how yours handles it.

Wash the bin with warm, soapy water, dry it completely, and wipe out the cavity it slides into. Grounds and coffee drips collect in there and are easy to forget. Machines with a removable brew group benefit from a weekly rinse of the group too, which we cover in our superautomatic cleaning guide.

Knock Boxes and Grinder Catch Cups

Semi-automatic owners have their own version of the grounds bin: the knock box. Empty it daily, since spent pucks grow mold quickly when they sit for a few days. Rinse it out and let it dry fully before the next round.

A grinder catch cup is a different story. It should only ever see dry grounds, so a quick brush-out is all it needs. Keep water away from it and from the grinder chute. Our coffee grinder cleaning guide covers the rest.

Dry Everything Before It Goes Back

Let every part dry fully, or towel it dry, before it goes back in. Trapping water under a tank or behind a drip tray undoes the whole point of washing it.

Seat each part firmly. A tank that isn't fully seated can leak or keep the machine from drawing water, and a drip tray that's slightly out of place can let drips land beside it instead of in it.

A Simple Schedule

Daily: Refill the tank with fresh water, empty the drip tray and knock box, and empty the grounds bin when prompted.

Weekly: Hand wash the tank, drip tray, grate, and grounds bin, and wipe out the spaces they sit in.

On schedule: Replace water filters and descale according to your manual.

Heavy users and milk-drink households may want to wash the drip tray more often. Our full espresso machine maintenance schedule puts these jobs alongside backflushing, gaskets, and everything else.

Frequently Asked Questions

Can I put my drip tray in the dishwasher?

Some trays are dishwasher safe and some aren't, so check your manual. Hand washing with warm, soapy water works for every tray and only takes a minute.

Can I clean my water tank with vinegar?

We recommend sticking with mild dish soap and water for the tank. Vinegar can leave a smell and taste behind, and it isn't a substitute for a proper descaler inside the machine.

What's the pink or slimy film in my water tank?

That's usually a bacterial film that forms when water sits too long. Wash the tank with warm, soapy water and a soft brush, rinse well, and switch to emptying and refilling it daily.

How often should I clean the grounds bin?

Empty it whenever the machine prompts you and wash it weekly. Busy households may need to empty it more than once a day.