The Moka Pot
Brewing with a Moka pot has little room for error and is more restricting in your control of the brew ratio. That said, they can make deliciously rich coffees when used properly. However, if used poorly they will make an undrinkably bitter cup.
Because of how they function, users have little control over the ratio. The basket must be filled to the top and water added to just below the lower chamber's valve. If not filled to these levels then the 'headspace' is increased, leading to quicker movement of water and not enough heat applied for a proper extraction.
Also, pay attention to the size of your Moka pot. Larger pots have a longer brew time and so the coffee grounds are more likely to be over extracted. Therefore, to avoid over extraction the grind size should be coarser with a larger pot and finer with smaller pots.
Brew time | 3-5 minutes
Brew Ratio | 1:5 - 1:8
Water Temp | Continuous heat source
Remember these are guidelines, experimentation is encouraged.
Boil your water
Boil enough water to fill the Moka pot's lower chamber with a kettle. It is important to boil the water first so that when the Moka is on the stove it doesn't take too long to heat the water. This will avoid burning of coffee powder, saving you from an overly bitter cup.
Grind your coffee
While the water is being boiled, grind your coffee to a similar coarseness for filter, perhaps a little coarser. If you are not too bound by your Moka's own basket size look for a brew ratio of 1:5, 100g to 500ml of water. This will make a fuller bodied brew with a more syrupy mouthfeel. Fill the basket with coffee but do not compress it.
Fill with water and apply heat
Now with your freshly boiled water fill the lower chamber up to the valve (the valve allows for the safe escape of pressure, do not cover). Fit the basket of coffee on top and fully assemble the Moka. Place the Moka pot onto your medium level heat source, the Moka lid open.
Watch your Moka Pot
Now watch the Moka work its magic. When the water boils the steam pressure pushes it up the tube and into the coffee bed. The higher the heat, the quicker the water will pass through the chamber. We do not want it to go through too quickly as this will result in under extraction, the opposite if too slow.
Finish the brew
Coffee will appear in the top chamber. Now it's time to listen to the pot. A bubbling or gurgling sound means that steam is escaping and all the water has been pushed through. If you are unable to hear this, look for excessive fizzing at the top of the tube. At this stage turn off the heat source as steam will make a more bitter brew.
Close the lid and quickly pour cold water onto the lower chamber. This will end the brewing process by causing the steam to condense, ending the pressure.
Pour, Clean and Enjoy
Pour your coffee and let the Moka pot cool. When it is no longer hot take the pot apart and clean it carefully. Once the pot is dry, remember not to lock the pot on too tightly as this will reduce the effectiveness of the rubber seal.