The humblest and most effective coffee makers are often the simplest in design. Through this simplicity, inspired by Bauhaus, they are often also the most robust coffee brewing apparatus.
Based on the simple principles of vapor pressure, the stove top espresso pot utilizes the increasing pressure of steam generated in the boiler to force hot water up a spout, through a screen of ground coffee and into the top vessel for collection and serving. By combining all of the functional elements into one individual unit that is made of extremely robust metal, the Stove top espresso pot ensures that you can brew coffee anywhere you can provide the essentials of heat, water and ground coffee.
There are a few techniques that can help you to brew the best coffee possible with one of these contraptions, and with care you can produce excellent results every time. You should know all of the parts of the machine, and what can go wrong if you haven’t assembled it correctly.
First, there is the base. As these machines come in different sizes, from single cup pots to 18 cup monsters, the size of the base varies accordingly. The principles upon which all of these sizes operate are the same, but the time it takes to brew increases with the amount of water that requires heating. The base is filled with water to a level just below the pressure release valve, often indicated by a line in the inside of the bottom pot. This line is present to show the amount of water that can be used without resulting in displacement of water above the level of the coffee, or the pressure release valve.
Incorporated into the walls of the base is a pressure valve, that if for any reason the pot reaches an internal pressure that is above that suitable for brewing coffee, or as a result of blockage, it prevents the vessel from becoming a very dangerous steam bomb. This is the same type of principle that operates in a pressure cooker, to prevent the extreme buildup and dangerous release of high temperature steam.
Once filled with water, the second part of the pot can be inserted. This is the strange, y shaped filter with a spout on the bottom that is filled with ground coffee. When filling, make sure that the grind is right, your local coffee shop should be able to provide you with a grind suited for it, and if you grind at home, it might be a good idea to buy a little bit of coffee ground for a stove top as a reference point for your own grind. Tamp the coffee down, by pressing it into place with an object that fits perfectly into the filter. This ensures the coffee does not have air pockets in it that may cause the water to tunnel through, resulting in an imperfect extraction.
Once the bottom half of the pot has been filled with coffee and water, it is time to screw the top half in place. This is the part in which the extracted coffee ends up. Check that the rubber seal is intact and in place, holding the find mesh sieve in place. The sieve prevents the coffee from running straight up into the spout, potentially blocking it. If it isn’t there and the internal spout is blocked, the pressure can build up to a point where a sudden release of coffee occurs, launching hot coffee grinds all over the room. Cleaning up a kitchen with coffee on its walls and ceiling can certainly get some interested looks from those you invited around for coffee.
Once all screwed in place, put the pot on the heat, and wait for the gurgling noise whereby the coffee has run up the spout and into the top vessel. Take it off the heat and pour the delicious hot coffee into hot cups. It can be a smart idea to place the cups around the element while brewing, to heat them up with the heat coming off the element. This only works on electric stoves.
Last, take care not to have the handle sitting over the heat, as it can melt and catch fire, resulting in the loss of your coffee.
