At our weekend get away, I found a 1940's Sunbeam C-30 Vacu-Pot at an antique store. For an item that is over 60 years old, this coffee maker looked brand spanking new. Ive been practicing with her for the last few days and am now accomplished enough to say this is some of the finest coffee i have ever had. The Aeropress is still the greatest but I need to be able to make more than 1 cup of joe atta time. Any buddy else out there use a vacuum brewer for their daily fix ? [vbpg]979[/vbpg] The Vacuum Brewer The high point of coffee gadgetry came in the 1920s with the introduction of the Silex "Vacuum Coffee Service Set". Heat resistant Pyrex glass had just been perfected and it was used to great advantage in that did not reheat the coffee once it had been infused. The essence of the vacuum method is that steam is used to BOTH brew the coffee AND keep it out of the water heater. This is a VERY tricky process as shown below: [SIZE=-1]Schematic of the Vacuum Coffee Brewing Method[/SIZE] The vacuum brewer has three parts: a server, a reaction chamber, and a filter. Cold water is placed in the server (lower part) and ground coffee is placed in the reaction chamber (upper part); a filter separates the two parts. The server and reaction chamber are arranged so that there is a steam-tight seal between the two. The filter is designed so that hot water can pass through it, but the mesh size prevents coffee grounds from penetrating. As the water is heated, the air trapped above the water also heats. As the air heats, it expands. Since there's nowhere for the air to go (because the neck of the upper unit extends below the water, the expansion of the air increases forces heated water to the upper chamber. (The reaction chamber is designed with a long narrow tube to ensure that it always below the water in the lower chamber. Because considerable pressure is exerted, the filter is held in place with a chain.) This continues until nearly all the water has been expelled from the lower chamber. At that time, the heated air (not steam) escapes from the lower chamber, equalizing pressure, and creating the characteristic burbling sound that tells you it's almost coffee time. The water remaining in the lower chamber continues to heat, but being heavier than the air, only a little of this water moves into the upper chamber, drawn by the escaping air. At this point, in the automatic machines, the water reaches the cutoff temperature which trips the switch and turns off the heat (or the user pulls the plug on the non-automatic ones, or takes the stovetop units off the stove). At this point, the process reverses. In the absence of heat, the air in the lower unit cools rapidly. As the air cools, it contracts, creating a low-pressure area in the lower unit. The difference in air pressure between the ambient air on the upper unit and the low pressure area in the lower unit is sufficient to draw the infused water through the grounds and filter back into the lower unit. Due to the slight loss of volume as a small amount of the original water has escaped as steam, there is always a slight vacuum hiss as the last of the water is drawn through the grounds, and some air is drawn in as the pressure equalizes. (Thank you, Mark Marburg!)
I recall someone bringing this up in the old Coffee thread about a month ago.. I think it was Joe or someone like that. They were going to grab one. They are pretty fun to watch as I remember.
Thanks for posting this Rick, brought back a lot of memories as my Grandmother had one similar to that one. Seems like she had to disassemble it to serve the coffee and she was always fiddling with it. Hope it works out well for you! There's something about using mechanical things from the past, must be the razor thing.
....the "razor" thing and the fountain pen thing and the newsboy hat thing and the golf thing and the bebop thing and the gray hair thing and.......... oh, who am I kidding ?? I AM "old school "
I am sure we are all pretty much screwed here.. too many nice expensive things out there to get addicted too
These things work great. I have one just like that and one that heats on the stove. I think I paid $2 for the stove top model and $6 for the electric one.
