Siphon coffee brewers, aka vacuum pots, were very popular in mid-century America. Every coffee shop had a Silex or a Cory. The waiter would fill a pot with cold water, seal another pot on top of it filled with ground coffee and then put it on a hot plate. After the water got hot in the lower pot, it was forced by steam pressure into the upper pot where it mixed with the ground coffee. After the coffee had brewed, both pots were taken off of the burner. As the lower pot cooled the coffee was sucked down through a metal, cloth or glass filter. It was an excellent way to make coffee.
Siphon brewers fell out of favor in the sixties and were replaced by automatic drip brewers. Now that consumers are demanding better coffee, siphons are coming back. 
Siphons provide three key elements that drip brewers do not, 1) good water temperature, 2) total immersion of the grounds and 3) even extraction. In addition, there is an esthetic pleasure in actually watching the brewing process. Some restaurants have begun to serve after dinner coffee in siphon brewers, partly because of the brewing quality but primarily because of the “Wow!” factor.
There are a number of manufacturers making siphon brewers. Hario’s glass siphons are at the top of the pile. Some of the others are Yama, Bodum, Starbucks and Cona. They are all available at Amazon and specialty coffee supply houses.
There are also balance beam brewers where the pots are side by side. The change in water level in the pots causes them to go up or down. In some, when the first pot goes up a spring activates a cap the kills the flame in the heater. They are often used in restaurants to enhance the “Wow” factor. Balance beam siphon brewers are very popular in Germany and Japan.
Heating the Water
If you are going to try a siphon consider how you want to heat the water. Most siphons do not come with a water heater. You have to provide a separate heat source. You can use your kitchen stove to heat the water which works very well. If you want to brew at the dinner table, some of the siphons come with alcohol burners. They are very slow to heat up so you have to put hot water in the pot to speed it up.There are also butane burners and electric burners. Hario is adding an electric halogen burner to its line this summer, however, just the burner will cost at least $250.
Hard to Clean
The biggest problem with siphon brewers is that they are hard to clean. We have a balance beam brewer at the Hula Daddy tasting room that we put out for our visitors to see. We have never brewed coffee in it. The tubes between the pots and the openings in the pots are so small that it would be impossible to clean out the coffee oils and grounds. Before you buy a siphon brewer check the openings to see if you will be able to clean the brewer easily. Also some burners leave a soot residue on the brewer, which can be hard to remove.
Needs Attention
You can’t push a button on a siphon brewer and go away. They have to be watched and adjusted during the brew. Failure to stay with the brewer can result in a cracked brewer and a huge mess.
Different Brew
You cannot expect siphon brewed coffee to taste the same as a french press or a Mr. Coffee brew. Given the same coffee beans, grind and brew time every method of coffee brewing creates its own unique coffee flavor. Siphon brews are rich in aroma and full of flavor. They tend to be cleaner and brighter than other brews.
Brewing Procedure
The basic procedure for using any siphon brewer is to fill the lower pot with water and start the heating process. While the water is heating, grind your coffee and put it in the other pot. Use the normal two tablespoons per six ounces of water.When the water starts steaming connect the two pots. Waiting to put the top pot on keeps water out of the grounds until the water gets to 200 F. As the water moves into the brew pot adjust the heat so that the water is just barely boiling. This will keep the water hot in the brew pot but not boil out the water in the lower pot. If the water boils out the lower pot may crack. Keep the heat on so that the brew time from the first infusion of water is about three minutes. You can adjust the brew time later for your own taste. After three minutes remove the pots from the heat and the vacuum in the lower pot will suck the coffee though the filter into the lower pot, giving you a close to four minute extraction time.
