What I check when my bean cooler isn't doing its job

icosonicof — Wed, 14 Oct 2026 08:03:39 +0000

Most sessions with the bean cooler are uneventful. When one isn't, the cause tends to be something in my own setup, so I work through a short list before deciding anything is actually wrong. I sort things by what I'm seeing, since each symptom has its own first suspect.

Nothing happens at the switch

The fan lives in the base, and the switch is a rocker on the front of it. If I press it and hear nothing, I check that the plug is fully in and the socket is switched on. It is made for UK mains at 220–240 V, 50 Hz, and I don't run it from anything else.

Chaff is landing in the wrong place

My first suspect is the sieve order. The 60-mesh one should sit directly on the base, with the 5-mesh one above it. The coarse mesh holds the beans and the fine mesh is where chaff is meant to end up. If I've swapped them, I put them right before the next roast.

I also ask whether I emptied the lower sieve after the last session. Emptying it is part of the routine for a reason, and skipping it is easy to do.

Beans still feel warm in patches

Before I blame the fan, I ask myself whether I stirred enough. Beans left in a hot pile is exactly what the instructions warn against, so I keep them moving across the top sieve while the fan runs. Next I look at the load. If there is clearly more than a normal batch on the tray, that's my mistake, not the cooler's.

The limits I keep to

Batch size: this is the 360 g version, and I treat that figure as the ceiling.
Tray: 17.5 cm across, so I don't heap beans above the rim.
Power: a 20 W fan on UK mains only.
Water: never while it's plugged in.
Placement: a flat surface, not a sloping board or the edge of the hob.

Care and storage checklist

Switch off at the rocker and unplug.
Pour out any beans left on the top sieve.
Tip the chaff out of the 60-mesh sieve.
Rinse both 304 stainless sieves. The painted-metal base can be rinsed as well, though I keep water well away from the plug and lead.
Leave every part to dry fully before stacking.
Store the base with both sieves sitting on it, so neither goes astray.

That's the whole list. I go through it top to bottom, because the early checks cost nothing and rule out my own setup first.