What size 4 means

Size 4 is the standard cone filter format used by most 8 to 12 cup home drip brewers. It is a cone with two crimped seams, one along the side and one along the base, and it sits in a cone-shaped brew basket rather than a flat-bottomed one. The number refers to the size, not the brand, so a #4 filter from any manufacturer will physically fit a #4 basket. What varies between brands is paper thickness, porosity and how much flavour the paper itself contributes.

Oxygen-whitened rather than unbleached

These filters are white, but the whitening is done with oxygen instead of chlorine. That matters because the alternative most people compare them to, brown unbleached paper, tends to carry a faint cardboard note into the cup unless it is rinsed well first. Technivorm’s own position is that oxygen-whitened paper gives a cleaner result, and that reusable wire mesh filters are the weaker option in a Moccamaster because they clog with coffee oils, which can slow drawdown enough to overflow the basket or over-extract the brew.

The filters are bonded without glue or chemicals, so the seams hold by crimping alone.

Rinse before brewing

Technivorm recommends rinsing the filter with hot water before adding coffee. It does two things: it washes out any residual paper taste, and it makes the filter cling to the basket wall so it stays open while you add grounds instead of collapsing inward. It takes about ten seconds and is the single easiest improvement to a drip brew.

Fit

Made for the 1 L and 1.25 L Moccamaster machines, which covers the KBG, KBGV Select, KBGT and similar models. Because #4 is a standard size, these also work in other brewers built around a #4 cone basket, including the Wilfa Classic and Classic+. Larger Moccamaster models and any flat-bottom basket brewer need a different filter.

Specifications

What’s in the box

• 100 Moccamaster #4 paper filters