French press

The size on the box is not in mugs

Widely documented

Presses are sold by a number of cups, and the cup in question is a small one, much nearer a teacup than a mug. A press labelled for eight cups holds around a litre, which is three or four mugs. Check the stated volume, not the cup count.

A press works best reasonably full. A large press used for a single mug leaves a shallow layer of coffee that cools quickly and is awkward to plunge. If you usually brew for one, buy the small one; if you sometimes brew for four, a large press half-filled is the worse compromise.

Glass, double-wall steel and plastic

Tendency, not a guarantee

Glass in a frame

The classic design. You can see the brew, and replacement beakers are sold for common sizes. Glass loses heat faster and breaks, usually in the sink.

Double-wall stainless steel

Keeps coffee hot far longer and survives drops. You cannot see inside, and the coffee keeps extracting as it sits, so holding heat is not the same as holding quality.

Plastic or ceramic bodies

Plastic is light and unbreakable, which suits travel. Ceramic holds heat well once warmed but is heavy and as breakable as glass.

What the plunger is made of

Widely documented

Cleaning, which is the real cost

Widely documented

1. Get the grounds out without the sink. A wet mass of coarse grounds can block a drain. Add a little water, swirl and tip them into a sieve, the compost or the bin.
2. Wash after every use. Coffee oil left on the jug and mesh turns rancid and flavours the next brew. Hot water and a little washing-up liquid are enough.
3. Take the filter apart regularly. Unscrew the stack and wash each layer. How often depends on use, but if the plunger smells stale, it is overdue.
4. Replace the mesh when it stops sealing. A frayed edge or a dent lets grounds past the screen. A new mesh is a small spare part and restores the press.

What a maker's instructions say about glass and hot water

Sourced

From one large maker's instruction sheet for its glass presses. Other makers' instructions differ, and yours are the ones that apply.

1. Use coarse-ground coffee only. The sheet gives the reason as safety, not flavour: a fine grind can clog the filter and create high pressure.
2. Leave room at the top and stir with plastic or wood. It asks for at least 2.5 cm of space below the rim, and warns that a metal spoon can scratch or chip the beaker and cause it to break.
3. Lower the plunger slowly, with minimal pressure. Hold the handle with the spout turned away from you and use little more than the weight of your hand. It asks for a brew of at least four minutes before plunging.
4. Check the glass before each use. A beaker that is scratched, cracked or chipped should not be used; a replacement is fitted in the same frame.
5. Keep it off the hob and away from children. These presses are not for stove-top use, and the sheet asks that children are kept away while one is in use.

The same sheet states that all parts of those models are dishwasher safe. Check your own before assuming it.

Who should buy something else

CoffeeHQ explanation

A metal mesh lets oils and the finest particles through. That is the source of the heavy, rounded texture people like, and of the silt at the bottom of the cup. If you want a clear, light-bodied coffee, no technique will get it from a press; a paper-filtered brewer will.

It also rewards a coarse, even grind. A blade grinder or a very fine pre-ground coffee produces more silt and a harder plunge. If the plunger resists, do not force it. One maker's instructions are to take the plunger out, stir the brew and then lower it again slowly, and they warn that excessive force can make scalding liquid shoot out of the pot. And because the grounds stay in contact with the coffee, anything not poured within a few minutes of plunging goes on changing. Decant what you are not drinking straight away.

What to do next

• How to brew with a French press — Ratio, steep time and how to reduce sediment, in full.
• Too much sediment — The commonest complaint, and what actually reduces it.
• French press vs V60 — Immersion through metal against pouring through paper.
• Frothing milk without a steam wand — A press doubles as a manual milk frother.
• Become a barista — A structured programme from dose and grind through milk, drinks and maintenance.