Tech Tip: Backflush Flashback

If you have a semi-automatic espresso machine with a 3-way pressure release, or solenoid, valve, you need to backflush it on a regular basis to keep the machine in fine working order. Backflushing will clean up behind the screen and into the brewing system, cleaning out coffee or grounds residue and reducing the potential for clogs.You can watch Dane as he cleans a Rocket Giotto, or follow these steps:

  1. Replace brew basket with a blind basket in the portafilter (or you can use this universal insert in your existing basket)
  2. Place 1/2 teaspoon of a backflush detergent such as Cafiza or Joe Glo (Important: make sure it indicates backflushing as its primary use on the label — do not use Dezcal or any other standard detergent here!)
  3. Insert the portafilter into the brew group and initiate a shot
  4. Allow the pump to run about 4 – 5 seconds maximum
  5. Turn the pump off and allow the water and suds to release through the valve
  6. Repeat this process until the water coming out of the valve is clear and suds-free
  7. Remove the portafilter, rinse it in cool water to cool it down and then switch out the baskets again
  8. Before you pull your first shot, run a blank shot through the system to make sure there is no residue leftover

23 thoughts on “Tech Tip: Backflush Flashback”

  1. I’ve had my Isomac Venus for 2 years and I was never advised to back flush – what does this mean ? I don’t think it’s as nice as the Giotto (3 way pressure, etc), but do I still need to back flus ? And if so, how can I get a blind basket ? I live in Vienna, Austria.

    1. I believe your model does have the 3-way solenoid/brew pressure release valve, in which case, backflushing would improve your shot quality. I would poke around for someone who sells espresso supplies — many commercial machines need to be backflushed, so you should be able to find the blind basket by looking for a commercial espresso supplier in your area. Alternately, the ‘universal fit’ backflush insert would be an easy thing to make, if you’re feeling handy. It’s basically just a rubber disc that you put into your existing portafilter, effectively blocking all the holes in the filter basket and then allowing for the backflushing to occur. You could probably make one of these pretty easily with some food-friendly plastic or rubber.

  2. Hi Kat!
    Your videos are great! I live in Bologna (Italy) and I have an E61 too (an Isomac Zaffiro).

    I saw your “how to backflush a 3way valve”, but here I cannot find the detergent you stated.
    What detergent (i suppose not chimical) could I get alternately to backflush my machine?

    Or is it possible to backflush without using a detergent?

    Thank you, bye!

    1. Hi there!

      Glad you like them — thanks for the feedback :)

      We use Cafiza or Joe Glo, but you should be able to find a suitable detergent at any place that offers commercial machine care supplies. It is a chemical and a soapy detergent; I’d think it would be better to use the detergent to break down the coffee and oils behind the filter, but you could just do the backflushing without detergent to clear out the valve…keeping in mind that it would not fully cleanse the system.

      Let me know if you have any other questions!

  3. Thank you very much Kat!
    Last year I went to Vancouver with my wife for holiday (Vancouver Island, British Columbia and Alberta, ALL beautiful places!); if I knew your site before, I probably come to Seattle to met you… sure, next time, I love these places

    Greetings from northern Italy, where there are a LOT of coffee “bar”, but a VERY few of them serves good quality espresso!

    1. Yes, it’s quite beautiful up there! I really love Alberta – very stunning.

      If you ever come our way again, please do stop in! Someday I hope to make it to Northern Italy so you’ll have to let me know where to stay away from when I do — can’t have bad espresso in Italy, now can I? :)

  4. In Bologna there is a shop named “Caffè Terzi”, who is really a purist in espresso:

    therefore, the site is only in italian, hope you can understand (but the espresso is GREAT, most of all I love the Indian Parchment Kappi Royal Robusta!)

    Here, a lots of coffee shop(in italian “bar”) are well equipped (most of them use the original Faema E61 Legend 3 groups, with Mazzer Jolly or Robur), but some of them produce a bad quality espresso because of the bad quality of coffee beans and the personnel not really interested in (because the owners want earn quickly too much )…


  5. Kat,

    I am watching the backflushing video and I have a Silvia (V3) machine and I am curious where the water will flush out of the Silvia if the portafilter is plugged. The video shows a machine with an extra valve? Do I take the portafilter out and pour the water out and then turn on again then turn off and pour the water out? up to 10 times like the Cafiza bottle says?


    1. Hi Jen –

      You have the same valve in your Silvia, but it’s behind the metal backsplash panel. You will perform backflushing the same way as demonstrated in the video, but you will see water/suds coming out from under the backsplash. Easiest way to monitor is to just remove the drip tray cover and you’ll see it there. Let me know if you have any other questions – thanks!

  6. Pingback: backflush
  7. Hey Kat, great videos with a very knowledgeable Gail. Waiting for the Cellini to come in, I have one question of many to com, should I install a Taylor thermometer on the E61?
    Please advise

    1. We installed one of these on our test kitchen machine and didn’t find any practical benefit with it. We want to test it some more, but right now the jury is still out on whether or not this is an upgrade/improvement to the system. Sorry I can’t be more concrete here!

      – Kat

    1. Hi there –

      No, you do not backflush any of the DeLonghi machines, as they do not have a solenoid valve that you need to clean out via backflushing. Performing this on your machine will damage it.

      Let me know if you have any other questions — thanks!

      – Kat

  8. I have an older white Rancilio machine. I believe it’s a Silvia. Possibly model #1. Do all the Silvia’s have the hidden backflush valve? Any hints on how I might be sure mine is equipped with such a valve?


    1. I haven’t seen any white ones, so can’t speak to their specific functionality. I know they had other models like the Nancy…my suggestion would be to call Rancilio and see if they can’t help identify your specific machine and then provide you specs from there. Sorry I can’t be of more assistance!

      – Kat

  9. I looked on the bottom and found out it’s a MISS. There was a serial number as well. I’ll try Rancilio, but looking underneath, it does seem there is an outlet leading into the backsplash plate. Thanks again.


    1. Also, when you’re done with a shot, do you hear a little depressurizing sound? And if you take the drip tray out can you see water coming down from behind the panel? There is a good chance it does have the solenoid valve…but just hate to give you bad advice that leads you to damaging your machine, yanno?

      Let us know what you find out!

      – Kat

  10. I have a Giotto Evoluzione. I do the backflush daily without detergent, and 1-2 times a month with detergent. According to the manual you can use head shampoo when backflushing. (I use special detergent for coffe machines bought at my local coffe shop) The manual also says that you can leave the machine on for 15 seconds or so(!) Is this beacuse the Evoluzione have a Rotary pump? Do you have any comment on this matter (use of head shampoo and 15 seconds backflushing)?

    1. I have not comment on using shampoo — we haven’t tested it and so I can’t speak one way or the other. You want to wait until you hear the pump laboring and then switch it off again; that duration will be different for all machines.

      – Kat

  11. Hi Kat,
    I cleaned my Rancilio Silvia for the first time. But, I made a mistake: I backflushed with dezcal. Did I break something (other than my blind filter)? What should I do now or is that no problem?

    1. That’s ok! Just go ahead and clean the brew head screen and the portafilter, and do a normal backflushing process using backflush detergent like Cafiza or Joe Glo. After rinsing, as you normally would when finishing backflushing, you are all set! You wouldn’t ideally want to confuse the two the other way around, so don’t put any backflush detergent into your water tank, as it is intended to clean coffee oils, not the scale buildup. Hope this helps!

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