Do You Need a Paper Filter in a Reusable K-Cup?

Short answer: no. A reusable K-Cup brews perfectly well with just its mesh basket. But most people who try a paper filter inside one keep using it. Here's what it actually changes, so you can decide.

What changes when you add paper

1. No grit at the bottom of the mug

Mesh has holes big enough to let the finest coffee particles through. They end up as silt in the last mouthful. Paper catches them, so the cup stays clean to the bottom. This is the main reason people buy filters.

2. Cleanup goes from a chore to a second

Without paper, you knock out the wet grounds, rinse the mesh and dry it before the next cup. With paper, you lift the filter out with the grounds inside and drop it in the bin. Nothing sticks to the basket, so you can brew a second cup right away.

If you brew for more than one person in the morning, this alone is worth the two cents.

3. A cleaner, brighter taste

Paper holds back some of the oils that mesh lets through. Most people describe the result as lighter and brighter, with clearer flavour notes. If you like a heavy, syrupy cup, you may prefer mesh on its own. It's a preference, not a right answer.

4. Less cafestol

Those same oils carry cafestol, a compound that can raise cholesterol in people who drink several cups of unfiltered coffee a day. Paper traps most of it. Worth knowing if you're a heavy drinker, though it's not a reason on its own.

What it costs

Between two and five cents a cup, depending on the size of the box you buy. For comparison, a pre-filled K-Cup pod usually costs 50 to 70 cents. Filters aren't what makes single-serve coffee expensive.

When to skip the paper

• You like a full-bodied cup. Mesh keeps more oils, and some people prefer that weight.
• You use a coarse grind and don't mind rinsing. Coarse coffee leaves less silt behind, so the difference is smaller.
• Your pod already has a very fine mesh screen. Some stainless steel pods filter well on their own. Brew a cup and look at the bottom. If it's clean, you don't need paper.

If you do use paper, three things matter

1. Use the right size. Too short and grounds slip over the edge; too wide and the paper bunches so the lid won't close. Most single-cup pods take the standard size, but the Keurig My K-Cup Universal and the K-Carafe filter need a taller one. Our fit guide lists them.
2. Use a medium grind. Paper adds resistance, so espresso-fine coffee makes the pod overflow. Drip grind is right.
3. Don't press the coffee down. Fill to the line and leave the grounds level so water flows evenly through them.

Common questions

Does paper make my coffee weaker?
No. It slows water down slightly, which if anything pulls a little more flavour out. Weak coffee is nearly always too little coffee or too coarse a grind.

Will it slow down my brewer?
By a few seconds. If it slows to a trickle, your grind is too fine or the mesh needs a wash.

Can I reuse a filter?
No. Wet paper softens and the second cup tastes stale.

Is paper worse for the environment than mesh alone?
A paper filter is plain paper and breaks down with the grounds. Compared with a pre-filled plastic pod, a reusable pod plus a paper filter is still far less waste.

White or unbleached?
Both brew the same cup. Here's the difference.

Can I make my own?
Yes, by cutting down a regular basket filter. Here's how, and what it costs.

Want to try them? Our filters start at a few cents a cup, with free shipping in the US and Canada.