Dishwasher safe coffee gear

The honest reason this matters is that a brewer you have to hand-wash gets used at the weekend and a brewer you can put in the machine gets used on a Tuesday. It is a usage specification more than a cleaning one.

The claim is usually about some of the parts

A French press is a glass beaker, a metal filter assembly and a plastic or wooden lid, and those three have different answers. Read the claim as being about whichever parts the maker names, and assume the others are not covered. Where a maker publishes it part by part we record it that way, because " dishwasher safe" on the box of a four-component brewer is not a single fact.

What a dishwasher actually does to things

Dishwasher detergent is strongly alkaline and the cycle is hotter and longer than washing up. That is fine for borosilicate glass and stainless steel. It dulls anodised aluminium, strips the seasoning and darkens the interior of copper and unlined brass, and it will eventually crack wooden handles and lids. Most cezves should never see one, whatever the listing says.

Top rack, and why

The heating element is at the bottom. Plastics that are fine at wash temperature will warp against direct radiant heat, which is what "top rack only" is protecting against rather than the water itself. It applies to most plastic lids, scoops and filter holders.

What the machine will not do

Coffee oil is not removed by a dishwasher cycle, and it is what makes an old brewer taste rancid. A metal mesh filter needs a brush and occasionally a soak in a cleaner made for coffee equipment, however good the dishwasher is. That applies most to French presses and immersion brewers, where the mesh is the part that holds the oil.