There’s nothing quite like the smell of freshly brewed coffee first thing in the morning. Whether your pick-me-up of choice is a sweet, creamy latte or a straight shot of double espresso, the unmistakable aroma of roasted coffee beans is the perfect way to start your day. Coffee is a part of people’s morning routines from Finland to Brazil, and there are almost as many coffee-making techniques as there are types of coffee.
Perhaps the most iconic piece of coffee-making equipment is the moka pot, a stylish stove-top coffee maker with sleek faceted sides, and a must-have in any Italian kitchen. Designed using futuristic lightweight aluminium by Alfonso Bialetti in 1933 and popularised by his son Renato in the 1950s, the Moka Express has since become a worldwide symbol of Italian style. It looks great, doesn’t take up valuable counter space like an espresso machine, and if you know how to use it, it makes a pretty fantastic cup of coffee, too. Check out our ultimate guide to the moka pot and you’ll soon be making perfect coffee every time.
How does a moka pot work?
This clever little pot consists of three chambers, a water chamber at the bottom, a small, puck-shaped chamber in the middle to hold the coffee grounds, and a third chamber at the top to collect the brewed coffee.
The bottom chamber is part filled with water, so it contains both water and air, and the pot is slowly heated on the stove. As the water heats up, it gives off water vapour, and also heats the air above it. Now comes the science part - when air is heated it expands, taking up more space in the chamber, and when water turns to vapour it expands too, so the pressure in the lower chamber gradually increases along with the heat.
When the pressure inside the lower chamber becomes too great, it pushes the water vapour up into the second chamber above, where it filters through the coffee grounds, each drop of water becoming infused with coffee flavour as it passes through. This coffee infused water vapour continues upwards to the third chamber, where the cooler temperature causes it to re-condense as delicious liquid coffee.
The coffee made in a moka pot is not technically espresso, which is extracted at very high pressures of around 9 bars. The moka is not made to withstand such high pressures, and is usually extracted at just one or two bars, but at more than twice the strength of regular coffee, it’s still the closest thing to espresso you can make at home without a lot of specialist equipment.
How to make coffee in a moka pot
Brewing coffee in a moka pot is quite simple when you know how. There are a few details you need to check to make sure everything runs smoothly, but once you know what to look for, it should become second nature.
If you haven’t used your moka pot before, the first thing is to do a few trial runs, either with just water, or used coffee grounds. This should wash away any rubbery flavour from the seal, and you can check the pressure relief valve is working at the same time.
Once your pot is ready to use, boil some water in a kettle or on the stove before adding it to the lower chamber. Pre-boiling the water reduces the amount of time the moka pot spends on the stove, so there’s less chance of the coffee grounds burning as it heats up. Moka coffee has a slightly unfair reputation for bitterness, which is usually caused by people overheating and burning the coffee.
Pour the pre-boiled water into the lower chamber to just below the pressure valve. It is important to have both water and air in the lower chamber for the process to work, so don’t be tempted to add more water hoping for a higher yield of coffee. There are several different sizes of moka pot, and each makes a set amount of coffee, so the only way to get more coffee is to use a bigger pot.
Next, add some coffee grounds to the second chamber. Freshly ground is always best in terms of flavour, and size-wise you should be aiming for fine to medium fine grounds, a little finer than filter coffee, but coarser than espresso grounds. Too fine and you risk blocking the filter screen between the lower and middle chambers. Level the coffee off with a knife, but avoid pressing it down as it is easier for the water to filter through loose grounds. Check for stray grounds around the edge of the chamber as this can affect the seal.
Make sure all the chambers are properly sealed together, and place the moka pot on the stove over a medium heat. Contrary to popular belief, the aim is not to boil the water, as this is another common cause of burnt grounds and bitter coffee. Instead, heat the moka pot slowly - the water will start to vaporise just before it reaches boiling point, and the pressure from the heated air will be enough to push it up into the chambers above.
You can leave the lid open on the third chamber to check how things are going, but it will be around 5-10 minutes before anything starts to happen. Take this time to moisten a tea towel and put it in the freezer - you will need it later. If the water is heating at the correct rate, you should eventually start to see dark brown coffee oozing slowly into the third chamber. If it comes through in a big gush, your water is too hot, and you need to turn the temperature down.
As the chamber fills, the coffee will gradually become lighter in colour, and by the time the liquid has filled about 80 percent of the way to the spout, it should have lightened to the shade of yellow honey. At this point, you need to stop the process, as all the good flavours have been extracted from the grounds, and further extraction will mar the flavour. Remove the pot from the stove, take your cold towel from the freezer and hold it over the lower chamber to cool it down and reduce the pressure.
Once the liquid stops pouring into the chamber, your moka pot coffee is ready. Serve and enjoy.
When you’ve finished with your moka pot. Hand wash it with mild detergent. Running it through the dishwasher will corrode the protective layer of oxidised aluminium, leaving the metal underneath exposed to react with the air, and creating an unpleasant taste.
If you want advice from an expert, check out these five tips for making the perfect moka coffee from Paola Goppion of The Goppion Caffè coffee roasting company.