• Siphon brewers and filters

    by  • April 7, 2011 • Coffee makers, Siphon brewers • 9 Comments

    With the growing interest in non-espresso coffee, siphon brewers are making a come-back. But although far from mainstream, these coffee makers, sometimes called vacuum coffee makers, or vac pots for short, have had always had followers. I’m one of those followers myself, and have been using siphon brewers for over a decade now.

    I often use my Kono and Hario brewers, which are just the right size and geometry for making great coffee. There is only one thing that not quite right about them: the filters. These popular Asian siphon brewers use cloth filters, and cloth filters are a real nuissance to clean. I do wonder, does anyone actually like these?

    My point is, there are better alternatives. The best ones in my opinion are found in Cona coffee makers, which come with glass filters.
    It may be difficult to understand how a glass contraption act as a coffee filter, but the history of siphon brewers has seen various types, and most work surprisingly well.

    The picture above shows five different glass drainer style filters that are relatively easily available. The bulb in the middle has a rough surface that acts as a filter. From left to right, these are two Cona drainers (new and old), two Cory filter rods, and a Silex Lox-in.

    The new model Cona drainer is still made to this day, and available from any Cona retailer. It works well in all siphon brewers, but its older brother (to the right of it) is my favourite. It’s larger and wider, and almost twice as heavy. Because of the low center of gravity, it sits very stable during brewing.
    I don’t recommend the Silex Lox-in, but the Cory rods will work too, although these tend to wobble a bit. You can find these and the old Cona drainers on ebay.

    Using a glass filter isn’t without some minor problems. For one thing, you need to be more careful when stirring the brew. Temporarily dislodging a glass filter can interrupt the brewing process. This can lead to more sediment in the cup, or, at worse, cause the coffee to be drawn down prematurely.

    Still, glass filters are a great alternative for cloth filters. The amount of sediment in the cup is hardly more than you would get from a cloth or paper filter. Compared to cloth filters, these glass filters don’t affect the flavour of the coffee, and cleaning is a walk in the park.

    So, why not simply use a glass filter in your Hario, Kono, or whatever other siphon coffee maker you normally use? I have tried this numerous times and found the Cona drainers to work well in the siphon brewers in my collection. Over the years I’ve come to think of these as more or less universal filters.
    Which makes me wonder, does anyone else use a Cona drainer, or other glass filter?
    Kono MM-2A with Cona filter

    9 Responses to Siphon brewers and filters

    1. eldric
      December 29, 2012 at 00:45

      Yep. Use one here in Melbourne. Mostly at home with a halogen lamp, but will be offering it in my cafe soon. Love how easy it is to clean (no rinse cycle!) And the taste. Prefer less acidic coffers with lots of mouthfeel, more on the nut/caramel flavour side. Find the oils you keep vs cloth filters are more noticeable.

      I had originally picked up a vintage Cory from the US but found that I could only do larger batch sizes well, so threw it in my spyhon. Works a treat.

      Have you ever tried the glass filters in the steel vacuum pots (that normally use a lock in style metal filter? I find the beam heater a bit slow, and want to experiment with the steel ones in an induction heater, also because I sometimes break the syphons in a rush because they are glass.

      • Jeremy
        December 29, 2012 at 03:28

        Cafe use is exactly what I have in mind for the glass filters. These are so much easier wrt cleaning than the cloth filters.
        The stainless steel vac pots are excellent for larger batches, which is a plus for rush hours. You won’t get the show, but you do get the brew quality.
        I’ve not tried a glass filter in a steel vac pot myself, but it ought to work as well. Only downside is that the brewing is interrupted when the filter is touched while stirring the brew. This might make the original Cory Nicro filter (with the two discs) easier to use for less trained staff.

        • eldric
          December 29, 2012 at 05:04

          I will definitely give the steel ones a try, I think the glass filter would still work the same way. Plus you can be a bit less careful with it.

          I am definitely pretty carefully not to touch the glass rod for sure, which can be tough as I prefer to constantly (slowly) stir and keep it in motion rather than letting it settle and creating a crust (which I believe leaves some grinds that are not fully extracted). So far hasn’t been an issue, just have to be careful.

          Planning on opening a cafe in Vancouver where filter (poor quality drip machines) rule, so using induction stove with a few steel vaccuum pots would probably be ideal as a higher quality version without having to use french presses, which are nice, but I find I lose the beauty of more delicate coffees.

          Time to hit up ebay I think!

          • Jeremy
            December 30, 2012 at 03:00

            Sounds like you got the technique right. Did you read Scott Rao’s book?
            It won’t be too difficult to find a few decent steel vac pots. Until recently Admiral Craft still made these, including their version of the Nicro filter. So there have to be a few around.
            Re. filter brewers, in addition to the vac pots, will you be using manual pour-overs? Maybe a few Kalita filters on a brew bar? Or perhaps a bunch of those Kinto Faro brewers we discussed elsewhere on our site?
            In any case, success with the cafe. Reading your comments, I’m sure it’ll work out well.

    2. Winnie
      June 12, 2013 at 06:09

      I’ve been using the hario 3 cup syphon for a while and recently got a cona glass drainer. The problem is the coffee clogs the drainer. I’ve tried coarser grounds but the problem persists. The brew does not drain down to the bottom after, I don’t know, 15 seconds or so and creates a vacuum at the bottom flask. Do I keep going coarser or is there something I can do? I use a hario hand grinder. Thanks.

      • Jeremy
        July 4, 2013 at 02:33

        Hi Winnie, it sounds like you’re using a grind that is a bit too fine. In addition, small manual grinders often produce a bit of fine dust that can stall the brewing. Try grinding a bit coarser, and brewing a little longer. See if that works better.

    3. June 21, 2017 at 12:53

      As manufacturer of the Cona Coffeemaker we recommend not to upgrade another brand, but simply combine our filter-drainer with a genuine Cona Coffeemaker. Premium quality combines better with premium quality.

      Only then you get to really enjoy a well balanced design, of which every component is superior to any other siphon brewer anywhere in the world.


    4. Michael Whiston
      March 1, 2021 at 06:42

      Until recently I’ve used the plate on offset plate spring loaded filter and then the cotton filter then I bought the stainless steel filter that was seated between two aligned stainless plates but it would clog and now I have the Cory glass filer rod that I picked up on eBay. I have to tell you I love the glass rod filter.

      The plate on plate was a pain to really clean well but it was fast with little or no stalls.
      The stainless steal screen was great but over time clogged and had toe be cleaned by burning the coffee grounds out. They don’t like being touched and bend easily.
      The cotton filter will give you the cleanest coffee but it’s hell to really keep clean and you’re replacing it all the time,
      The glass filter rod, I have to tell you works great and is a dream to clean. The glass doesn’t carry any taste or odours. A quick wash with a not to abrasive cloth, the one I use for the other parts of my Yuma Vacuum coffee maker and all is well.

      I’ve been using a vacuum coffee maker on and off for 45 years and the best one I’ve used so far, the Yuma sy-8 and it’s been 10 years with the same one and it gets a lot of use. I drink 2 pots a day and that works out to 80ozs. a day which works out to +or- 2,4 liners.of strong black nectar of the Gods.

      Enjoy your coffee.

      Michael from Toronto, Canada

      • Jeremy
        March 1, 2021 at 21:13

        Thanks for your reply, Michael! I quite enjoyed the double plate (I think these were made by Nicro for the old metal vac pots?) You’re right these work very nicely with a quick draw down. Cleaning is a bit of a pain, but a bit of Cafiza or similar coffee cleaner and a gentle scrub with a toothbrush does a good job.
        The various glass filters from Cory and Cona are a bit slower at filtering, but otherwise I’ve not found any issues over the years. Both use and cleaning are much easier, which is why I decided to post the article.
        Anyway, it’s been good to hear about your experience with different vacuum coffee makers and various types of filters!
        Keep enjoying your coffee!

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