Chemex filters are a big part of why a Chemex brew tastes the way it does. The bonded paper is heavier than a typical cone filter, so water moves through the coffee bed more slowly and the paper traps very fine particles and most of the coffee oils. The result is a bright, clean cup with almost no sediment. Chemex cuts every filter in its own factory, and the paper is made in the USA from North American wood certified under the SFI, FSC and PEFC programmes.

Square or circle, white or natural

Chemex makes the same bonded paper in several formats, and they all brew the same way. With squares like these, four points stick up above the rim of the carafe, which some people find easier to grab when lifting out a wet filter. Pre-folded circles sit flush with the top of the glass instead. White filters are cleaned in an oxygen bath followed by hot water rinses, while natural (brown) filters only get the hot water rinses and keep the colour of the wood pulp. Neither is chlorine-bleached, and Chemex says the choice comes down to preference.

Placing the filter

Each filter has three layers of paper on one side and one layer on the other. Open it into a cone and place the three-layer side against the spout. The thicker side is stiff enough to stay put, which stops the paper from sealing against the glass at the spout. If that happens, air cannot escape as the coffee drains and the brew slows to a crawl. Rinsing the filter with hot water before adding the coffee washes out any paper taste and warms the glass. Pour the rinse water away through the spout before you start brewing.

Grinding for a Chemex

Thick paper means a slower drawdown, so a Chemex usually wants a medium-coarse grind, a little coarser than for a V60 or similar cone. A full 8 or 10 cup carafe also takes a lot of coffee, which is slow going in a hand grinder. An electric filter grinder with a hopper, such as the Eureka Peppe, handles those larger doses in one go and lets you adjust the grind until the brew time lands where you want it.

Specifications

What’s in the box

• 100 Chemex Bonded FS-100 pre-folded square filters