Brewing coffee in a vintage steel vacuum pot

Maybe two or three years ago after returning from Japan, I decided I wanted to try replicating the siphon coffee that we were served for our first breakfast. I some research and found out that they used to be very common in the US before auto-percolators took off in the 1960s and were known as vacuum pots because the brewing process created a vacuum, in the bottom chamber, drawing the brewed coffee down into it. I then bought a Nicro Model 500 off Craigslist with the metal filter, figuring it would be less prone to breakage than glass and easier to clean than a cloth filter, which is the style that is used today in Japan.

The problem is, I could never make good coffee. The water wouldn’t heat up to the suggested 205 degrees and it would clog instead of draining.

Then, this past month, I tried it again and it made excellent coffee. It was complex, deep, clean, and even warmer at first sip than a pour-over. I used:

  • a light generic breakfast roast
  • a 17.5:1 ratio
  • a grind size similar to pre-ground drip coffee
  • 900g of water, enough for three mugs of coffee
  • no temperature measurement, only turning down stove and waiting for water to stop bubbling in the upper chamber
  • coffee steeping for around a minute, then turned off gas and let coffee drain

Full brew time was somewhere from 5-7 minutes.

I started thinking how I might have lucked into such a good cup and I realized that a big batch, high ratio, drip grind generic coffee, and no temp control is probably how the device was meant to be used in a 1950s kitchen or diner, where there wouldn’t have been fancy grinders, temp probes, or even time to fuss over the coffee like I would with a manual pour-over.

Fresh off a few great cups, I tried brewing an Ethiopian light roast and it went right back to clogging from all the fines. I guess to use this siphon, I have to keep my coffee styles from the 1950s as well.

For those of you interested in more historical detail, I was able to find old manuals to research my process, and old advertisements to roughly date my coffee pot at this site.