The vacuum brewer has been around since the early 1800's. Basically the vac pot has two globes; one is loaded with water and the other with coffee grounds. They are connected together (one on top of the other) and the water and coffee are kept separate. There is a connecting tube that has a filter on one end and that is sitting in the globe with the grounds (the top globe). The water is heated and begins to create vapor pressure. As the pressure increases, the water is forced through the tube into the top globe with the coffee grounds. As long as heat is applied to the bottom globe the water will remain, mixing with the grounds, making a wonderful brew. When the heat is removed, the globe begins to cool. When a gas cools it contracts (oh, God, that Boyles law thing again from school) and this creates a vacuum, drawing the coffee beverage through the filter-covered tube. The coffee grounds stay in one globe and the brew is now in the other, ready to serve. Another nice consequence of all this is that the coffee is brewed at the ideal temperature. Remember, the water never boils.
The double glass pot was used prolifically in the early 1800s and was almost identical to the glass vacuum pots available from Bodum or Hario or Yama. Problem was many of the glass globes would break since their quality control methods were not on a par with today's standards. Be that as it may, the balancing siphon came on to the scene about 1844 and was invented by a Louis Gabot. With this device, the water container and the coffee container were placed side by side. The containers were balanced and as the water was heated and forced out one side, that holder would become lighter causing it to move. This would eventually trigger a cover to come over the heater (a small alcohol lamp) and extinguish the flame. Apparently a Scottish naval engineer, Robert Napier, invented a very similar device in the 1840ís. His device did not automatically extinguish the flame but used the same principle as Gabot's. The Cafetino works on this principle.
At first glance the Cafetino is a quality piece of work. It is well put together and all edges are clean. The Cafetino is not as small as it appears in some of the pictures that you can find on the web. It will brew a liter of coffee. The stainless sphere (which initially contains the water and will eventually contain the coffee brew) looks like it came from a Jules Verne Novel and has a handy little spigot on it used to dispense the coffee. The sphere sits in a frame that is held up by spring shock absorbers. The sphere will ride up as it is emptied. The siphon tube is sturdy and the filter on the end is metal and very fine. This will be placed in the hand blown glass goblet that the coffee grounds are placed in. The spirit lamp is easy to fill and sits under the sphere. The spring loaded cover is held open by the filled sphere as it sits low in it's frame. As the water is forced out the sphere, the sphere rises and eventually the cover on the lamp slams shut. It looks very impressive when in use and would add a nice, entertaining touch to a dinner with friends
I tried the brewer with some coffee I roasted. I ground it fine (in-between espresso and drip) and placed this in the goblet. The instructions recommend 30 grams for 1/2 liter, 60 grams of ground coffee for the full liter. Although the lamp could eventually heat the water enough for the pot to work, it is easier to pre-heat some water and place this in the sphere. (Be very, very, careful when doing this..the sphere is an excellent conductor of heat..I am a little embarrassed to tell you how I found that out, but draw your own conclusions). The water moved out into the goblet, mixed with the coffee, the lamp cover slammed shut, the coffee was drawn back into the sphere and I was ready to go. You do have to remove the end of the siphon tube from the sphere to begin pouring. Again, be careful.
The coffee was fantastic! It was hot, smooth and contained no grit at all. It was not hard to clean but I could see purchasing a small bottle brush to clean the inside of the sphere more thoroughly.
I love this work of art. I purchased it on Ebay and would recommend it highly to anyone looking for a showy piece and a great cup of coffee!