How to Use a Percolator

A percolator is a pot with a tube up the middle and a basket of coffee near the top. As the water in the base heats, bubbles force it up the tube. It sprays over the coffee, drips back down through the basket into the pot, and goes round again. You watch the brew darken through the glass knob on the lid. It was the standard way to make coffee in American homes until drip machines took over in the 1970s, and it is still the pot most people take camping.

Its reputation for bitter coffee is earned, but it is not inevitable. The same coffee keeps cycling back through hot grounds, so excessive heat or time can make the brew harsh. Run it too hot or too long and it stews. Gentle heat, a coarse grind, less coffee than you would use in a drip machine, and a short perk fix almost all of it.

Start with this recipe

For a stovetop percolator that holds at least a liter. Makes about 24 ounces, enough for three mugs. For other pot sizes, see the table below; the steps are the same.

1. Fill the pot with 800g of cold water. Check that the water stays below the bottom of the basket once the basket is in place.
2. Fit the stem and basket. Add 40g of coffee to the basket, ground coarse, and shake it level. That is about 8 level tablespoons.
3. Put the spreader plate on top of the basket and close the lid.
4. Set the pot on medium heat and wait for the first burst of coffee in the glass knob.
5. As soon as it starts to perk, turn the heat down to medium-low and start a timer. Aim for a gentle perk every few seconds, not a constant gush.
6. Let it perk for 6 minutes. Use 5 for a lighter pot, or up to 7 for a stronger one.
7. Take the pot off the heat and let it settle for a minute. Use a heatproof mitt to handle the hot lid, basket, and stem, following the pot’s instructions. Remove the basket before pouring.
8. Pour, and drink it while it is hot.

The water you start with is the coffee you get, minus what the grounds soak up. That is why the pot never needs topping up. It also means you should never let a percolator run dry.

Why it uses less coffee than drip

A drip machine passes water through the coffee once. A percolator passes the same water through again and again, close to boiling. This site’s starting recipe uses 1:20, about 1g of coffee to 20g of water, where drip uses 1:16. Use the drip amount in a percolator and the cup can come out stronger than you want. Adjust after tasting; repeated circulation does not guarantee a particular extraction or strength.

The same is true of the big percolating urns used at events; see coffee for a crowd.

How much coffee for your pot

Percolators are sold by “cups”, and most brands count a cup as about 5 ounces, not a full mug. A “12-cup” percolator holds about 60 ounces of water. Measure by the water, and hold the ratio at 1:20:

Coarse coffee is a little lighter than finely ground coffee, so a level tablespoon of it is about 5g. If you have no scale, how much coffee per cup covers why spoons drift and how to calibrate one. The brew ratio calculator works out the coffee for any amount of water.

Check the basket. The water line has to stay below the bottom of the basket, or the coffee sits in water and steeps instead of percolating. Most pots mark a maximum line inside. A basket that is close to full with this much coffee is normal; one that overflows means the pot is too small for the batch.

Heat: a gentle perk

Heat is the main control, the same as on a Moka Pot. Watch the glass knob:

• A burst every two or three seconds is right. The coffee in the knob darkens slowly.
• A constant gush, rattling, or a rolling boil means the heat is too high. Turn it down. Hard boiling is what makes percolator coffee taste burnt and bitter.
• Nothing for more than a minute after it has started means the heat is too low. Nudge it up a little.

On gas, keep the flame under the base, not up the sides. On an electric hob, which reacts slowly, turn it down a minute before you expect the first perk.

Perk time

Start timing at the first perk, not when the pot goes on the stove. Heating the water takes anywhere from 5 to 10 minutes, depending on the pot and the burner, and none of that counts.

Six minutes of perking is a good middle. Each extra minute makes the pot stronger and more bitter; each minute less makes it lighter and brighter. Change it a minute at a time. The color in the knob is a rough guide, but a timer is more reliable, because the knob shows the coffee passing through the top, not what is in the pot.

Grind: coarse

Use a coarse grind, like sea salt. Coarse grounds stay in the basket, and they extract slowly enough to cope with being brewed over and over. See the grind scale.

• Too fine, and grounds slip through the basket’s holes into the pot. The coffee over-extracts and turns bitter and muddy.
• Too coarse, and even a long perk tastes thin and weak.

Pre-ground coffee is usually ground medium, for drip machines, which is a little fine for a percolator. It works, but expect some grounds in the pot. A paper filter disc in the bottom of the basket fixes that.

Paper filters

Round paper filters with a hole in the middle for the stem are sold for most percolators. Put one in the bottom of the basket before the coffee, and wet it so it sits flat. It catches the fine particles that make the bottom of the pot muddy, and it holds back most of the coffee’s oils, which gives a lighter, cleaner cup. Without one, the metal basket lets through more oils and sediment; filtered vs unfiltered coffee explains what that changes.

Electric percolators

An electric percolator runs the whole cycle for you. It heats, perks, and switches to a keep-warm setting when the brew is done, usually after about a minute per cup.

1. Fill it with cold water to the line for the number of cups you want.
2. Add the coffee from the table above to the basket, and assemble the stem, basket, and lid.
3. Plug it in and switch it on. Leave it alone until the light shows it has finished.
4. Unplug it before opening it. Follow its instructions for removing the hot basket and stem, and use a heatproof mitt rather than touching the metal with bare hands.

You cannot change the perk time or the heat, so the coffee dose and the grind are your only controls. If the pot tastes bitter, use a little less coffee or a coarser grind next time; if it tastes weak, use a little more. Keep-warm slowly stews the coffee, so drink it within half an hour, or pour it into a vacuum flask. Never put the base in water, and unplug it before you clean it.

Percolator coffee when camping

A stainless steel stovetop percolator is the classic camping brewer: one pot, no filters needed, and no glass to break apart from the knob.

• On a camp stove, use the recipe above. Camp burners run hot, so turn yours right down once it starts to perk, and shield the flame from wind.
• On a fire, use coals rather than open flames, and control the heat by moving the pot toward or away from the hottest part. Keep the handle away from the fire.
• Pre-measure the coffee into a bag or jar at home, so you only need to measure the water at camp.

Lift the basket out before you pour, even outdoors. Grounds left in the pot keep brewing as long as it stays hot.

Fix the cup

The Brew Compass turns any of these into one change for the next pot. For the reasons behind sour, bitter, and weak, see fix sour, bitter, or weak coffee.

Cleaning and care

Let the pot cool, then knock the grounds out of the basket and wash the basket, stem, spreader, and pot in warm, soapy water. Coffee oils build up quickly in a percolator, because so much of the brew touches the metal, and old oils make the next pot taste stale and metallic.

• Clear the stem. Run water through the tube and check that nothing blocks its base. A blocked stem cannot perk.
• Aluminum pots are usually washed by hand. Dishwasher detergent dulls and discolors them. Stainless steel is tougher; check the manual.
• Descale when a white crust builds up inside, more often with hard water. Use a descaler or the method in the manual, then run a pot of plain water through and discard it. What water is best for coffee explains why hard water scales faster.
• Check the glass knob. It is held in by a small seal that can wear out and leak.

Percolator, Moka Pot, or drip?

They are easy to confuse, and they make quite different coffee.

• A Moka Pot pushes water through the coffee once, under steam pressure, and makes a small amount of very concentrated coffee. It is the better choice for strong coffee and milk drinks.
• A percolator cycles the same water through the coffee many times and makes a full pot of strong, hot, full-flavored coffee.
• A drip machine passes the water through once and makes a full pot of cleaner, milder coffee with no attention at all.

If the percolator’s robust, roasty cup is what you like, it is a fine brewer. If you keep fighting bitterness, a drip machine at home or a French press at camp makes a smoother pot for about the same effort.