High design: the design of the Cona Table model vacuum coffee makers descends from the Cona Rex, which was designed by Abram Games in 1947 and manufactured throughout the 1950s. Ease of use: the carafe is removable from the stand for pouring and the stand doubles as a funnel holder and includes a drip catcher. Clean cup: brewer and filter rod are made exclusively out of glass, which imparts no off tastes to the coffee.
Negative Product Points
Stock setup uses a spirit lamp (alcohol burner), which does not allow for precise temperature control. Temperature control with the spirit lamp is binary, either on or off, which is crude by contemporary siphon brewing standards. [See workaround below.]
While I have several siphon brewers, none of the others can match the aesthetics and ergonomics of the Cona tabletop vacuum coffee maker. There simply is no finer brewing system for a special brunch or an after dinner pot of coffee. You can brew a pot at the table with your guests, while curating the cup that you are about to serve. Your guests will be amazed by the presentation as well as the coffee.
The Cona glass is high quality. It compares favorably other siphon brewers. Only the hand-blown glass used in products like the Kono siphon brewers is thicker. The chrome plating on the stand is also top-quality. My Cona Model C brewer is a couple decades old and shows no signs of aging.
While temperature control with the stock set up is problematic, there are a couple workarounds that allow for the use of an adjustable butane burner. One, you can cut a 3.5" diameter hole in a cutting board, which will allow you to recess a butane burner within the hole in the base of the stand. Two, you can get a purpose built siphon brew board for Cona vacuum coffee makers. (Search for "siphon brew board" on Etsy.) This brew board not only accepts a butane burner, but also allows you to display and transport your Cona vacuum brewer in style.
An Executive Council member of the Barista Guild of America provided me with the following siphon brewing guidelines as starting point: • Coffee to water ratio: 60–70 grams of coffee per liter of water (up-dose slightly as compared to pourover). • Target siphon brewing temperature range: 195–200°F (target higher temperatures in this range for lighter roasted coffees and lower temperatures in this range for darker roasts). • Grind size: medium grind, equivalent to Kalita Wave or Hario V60 pourover grind size (#6 setting on Baratza). • Total brewing time: 3.5¬ to 4 minutes, drawdown included.
Off stage: Preheat brewer before adding brew water; pre-heat brew water to 210–212°F before filling carafe; add brew water to pre-heated carafe (ideally, using a scale to weigh the brew water); dose and grind coffee.
At the table: Hang the filled and pre-heated carafe; fire up the burner; and set burner relatively high for bulk heating. Since the brew water will lose heat on the trip north, heat the water in the carafe until it is 5–10° above target brew temperature before installing the funnel. Once the water is up the funnel, roll the flame height back to avoid aggressively boiling the remaining water (escaping vapors can cause the glass rod to bounce and let grinds into the cup). Confirm brew temperature (if too hot, stir with paddle to cool); add ground coffee; start timer; gently paddle grounds back and forth, like breaking the crust in cupping, to wet grounds evenly without disturbing the glass rod. Gently stir the slurry in a circular motion around 2:00 or 2:30 and extinguish the flame. Drawdown should complete between 3:30 and 4:00.
Brew board: by CoffeeBOS, available on Etsy Butane burner model: B302 Professional Grade Micro burner (or similar) Digital thermometer model: ThermoWorks Thermapen (or similar)
These are not inexpensive brewers: The Model C and Model D brewers are available new from Sweet Maria's for roughly $220. These brewers only occasionally show up used on eBay in the US and do not sell at much of a discount when they do. The best alternative to buying new is to shop eBay in the UK, France or Germany. The smaller Model A and Model B tabletop brewers from Cona are only available used.
Three Month Followup
Our neighbors now bring their out-of-town friend to our house for coffee. The Cona Model C is the star of the show. I've added some proven brewing parameters and guidelines above.