A percolator passes already-brewed coffee through the grounds repeatedly, at or near boiling. That is a recipe for over-extraction, and grind is your main defence.
The setting
Coarse — noticeably coarser than French press. Large, distinct particles.
Fines are a particular problem here: they fall through the basket into the pot and continue extracting for the whole cycle.
Why coarse
Every pass through the bed extracts more. Over seven to ten minutes and many cycles, a medium grind will be far past its useful extraction.
Coarse slows each pass and keeps the total in range.
The other controls
Stop early. Seven to ten minutes from the first perk. Watch the glass knob — a slow steady blip, not a furious rattle.
Lowest heat that maintains perking. As soon as it starts, turn it down.
Remove the basket immediately when done, and take the pot off the heat.
The ratio
Around 55 g per litre, slightly less than filter, because the extraction is more aggressive.
What to avoid
Pre-ground filter coffee, which is far too fine for a percolator and will produce something genuinely unpleasant.
A blade grinder, whose fines will pass straight through the basket.
Where percolators earn their place
Camping and large gatherings — robust, no filters, works on any fire. For quality, a French press over the same fire is better.
Last reviewed 8 August 2026