Tech Tips

Imat / Quaha owners' information repository

Tech Tips

Disclaimer: The operations listed below has been performed with no complications other than those described, and have yielded satisfactory results on my own machine, but all work is performed at your own risk, after your own assessment of whether you or the person performing the work has the mechanical skills to do so. It should be simply a matter of following the instructions, but since manufacturers can change their specifications over time and since I can make no guarantee as to the skills of the person performing it, I can take no responsibility if your machine is damaged during the operation.


Setting up your machine
If you've just purchased your new Imat / Nemox / Quaha machine, you may be confused as to how to use your machine. Buyers from Coffee For Connoisseurs probably received a useful setup guide, but others may benefit from a setup guide. Note that this operation was performed on a Quaha Napoletana II, so there may be subtle differences with rebadged variants.

You're probably itching to get into things and start using your machine, but before doing so I recommend loosening your showerscreen screw. The screw is typically quite tight, and this will only get worse over time, making it very difficult to remove the showerscreen later on for cleaning.

Look up at the showerscreen and you should see a screw or nut in the middle of the showerscreen. In my case I needed a stubby Philips #2 screwdriver to remove this, but it may be different in your case. Apply firm pressure against the screw and try to turn it anti-clockwise. You can actually invert the whole machine if you wish (after removing the water tank!) to apply even more pressure onto the screw head, but ensure the grinder hopper is sitting off the side of your workbench so you're not applying pressure to the plastic hopper. Once you've loosened the screw, tighten it with moderate pressure and continue as below.

  • After unpacking your machine, remove the water tank and fill it with water. Before replacing it in the machine, look inside the cavity which houses the water tank and you should see a white rubber hose running against the front panel of that cavity. Make sure the bottom end of this hose is sitting in a hole in the bottom of the cavity, as this will carry pressurised water from the grouphead to the drip tray on backflush! Refit the water tank
  • Replace both the hoses into the water tank - one of them should have a conical filter, which is the water inlet hose.
  • Turn on the machine at the main switch, and also on the front panel. A light should glow to indicate the machine is turned on.
  • Place a container (cup, mug, steam jug, etc) under the steam wand. Turn the steam knob into the fully open position (normally anti-clockwise) and turn on the pump switch (the rightmost of the two small middle switches). The pump should start, and eventually water should start flowing from the steam wand.
  • Turn the pump switch off and close the steam wand.
  • Turn the brew switch on (the large one at the far right); the pump should start and water should start to flow from the group head.

You have now filled the boiler with fresh water and are ready to start a brew!

Using your machine
Having got everything ready to go, let's make a brew!
  • Turn on your machine
  • Load the single filter basket into the portafilter (the thing which holds the basket).
  • Grab some fresh beans and tip a heaped tablespoon of beans into the grinder (if there are already beans in the grinder, you may wish to remove these and run the grinder to empty the last bits out)
  • Turn the knob at the side of the grinder until it is around the '3' area. You will need to fine-tune this once you've got the hang of using the machine.
  • Push the portafilter against the button between the prongs beneath the grinder outlet to start the grinder
  • Let the portafilter come back to stop the grinder when you've got a pile of coffee grounds just above the top of the basket. Shake the portafilter from side to side to level out the coffee and repeat, until you have a reasonably flat dispersion of ground coffee up to the level of the top of the basket.
  • Tamp this ground coffee firmly. If you use the built-in tamper, you'll find you need to tamp at least a dozen times to get it all tamped, because it's not a very good fit. The tamper tip tells you how to get a better tamper for your machine! Otherwise if you've got a correctly-sized tamper, give it one firm tamp, similar to how hard you would push when juicing an orange in an orange juicer.
  • Load the portafilter into the grouphead and pull it around firmly until it's a bit past straight ahead
  • Get an espresso or cappuccino cup and put it underneath the coffee spouts.
  • Wait for the heating light to go out, and then turn on the brew switch. You should hear the pump start up, and a few seconds later espresso should start flowing slowly into the cup.
  • If the pump goes quiet and no espresso comes out, you've either:
    • ground the coffee too fine, and / or
    • put too much coffee into the basket, and / or
    • tamped too hard.
  • If the espresso flows quickly and has a pale brown / blonde colour, you've either:
    • ground the coffee too coarse, and / or
    • put too little coffee into the basket, and / or
    • tamped too softly.
  • Ideally you should get about 30ml of espresso in 25 seconds. This can be hard to judge as it happens, but ideally the coffee should flow slowly from the spouts, almost to the point where it's coming out drop by drop but not quite. You should see a reddish / brown crema on the top of the coffee. When you've got your 30ml (or if you don't have a measuring cup, when the flowing coffee starts to turn pale), turn off the brew switch. You should hear a sneezing sound as the 3-way valve dumps the excess pressure in the grouphead into the drip tray.

If you just want espresso, stop now and enjoy it! Otherwise, keep reading for the steaming section.

  • Turn on the steam switch. The heating light should come on.
  • Pour about 150ml of milk into a suitable jug
  • When the heating light turns off, open the steam knob a little bit to bleed off the water. Close the knob once only steam comes out.
  • Submerge the tip of the steam wand about 1cm below the surface of the milk and open the steam knob about 1/3 of the way. Angle the jug so the milk starts spinning in a whirlpool, and lift the steam wand up so it *just* comes above the surface of the milk. It's a delicate operation, but if you get it right the sound should go higher and you should hear air being incorporated into the milk. If you get big bubbles, you've gone too high.
  • Keep going with this operation, progressively open the steam wand all the way as the foam on the surface starts to form, until the sound gets deeper and deeper and the side of the jug feels very hot. Turn off the steam wand.
  • Important: At this point make sure you turn on the pump switch (not the brew switch) to refill the boiler. Turn off the steam switch if you don't want to make another brew.
  • Pour the foamed milk into the cappuccino cup and dust with chocolate. Enjoy! :)
Tamper
The original plastic machine-mounted tamper on these units is 53mm in diameter, which is the perfect size for the bottom of the double filter basket. Unfortunately, most people don't generally tamp an empty basket, and by the time it's full of coffee, you need a 57mm tamper. Using the existing tamper means chasing the coffee grounds around the filter basket, and trying to get an even tamp. This is very difficult to do with an undersized tamper, and introduces just another variable in the attempt to maintain conditions and produce repeatable coffee.

Enter the Vanilla tamper, a replacement for the undersized built-in tamper. I made this tamper to combat the problems of the original item, and it achieves an even tamp across the whole coffee in a single action; it reduces the frustration in having to perform up to a dozen tamps, and allows even tamp pressure and therefore more control over the final brew. Since then I've started using a Deluxe tamper which is quicker to use and gives a firmer tamp and better results. Either tamper are capable of the result shown below with correct other techniques.

Photo of an even pour


Grinder
The grinder doesn't dispense coffee in the middle of the filter basket. I'm still working on a satisfactory solution for this one, though it's only a very minor annoyance.


Water Distribution / wormholes
The water for these machines enters the portafilter via 4 main water outlets located at the centre of the grouphead. While the showerscreen attemps to spread this water across the coffee area, inevitably the coffee closer to the water outlets will get more flow, pressure and heat than the coffee towards the outer edge of the filter basket. If you're using a fine grind, this can result in water being bored into the coffee. This is evident by 4 'wormholes' around the centre of the 'puck'. The result of this is uneven extraction of the coffee. To address this, I've made a brass diffusion disc which sits between the grouphead and the showerscreen, and channels the water away from just the centre, and allows even release across the whole coffee area. Being brass, heat transfer is maintained and water susceptibility is not an issue. The only potential issue caused by the diffusion disc is a possible slight reduction in effectiveness of the 3 way valve, meaning pucks may not be quite as hard and dry as before. This though is largely theoretical, I haven't noticed a great change myself.


Water leaking from under the drain tray
You may have noticed water running from underneath the drip tray. On machines fitted with the 3-way valve, the valve dumps the pressure from the grouphead into the drip tray via a rubber hose when the brew switch is turned off. The end of this hose should be visible by the side of the machine if you remove the drip tray. If not, remove the water tank and you'll see it hanging loose inside the water tank cavity. There's a hole it should go down to dump the water into the drip tray.

Even if this hose is in the right place, the rapid water flow from the grouphead can still cause some overspray when the brew switch is turned off. I got around this problem by wrapping a cable tie firmly around the hose where it exits the machine and sits above the drain tray (opaque white rubber hose at the left hand end of the machine, above the drain tray), to slow the rate of release.

Note: tighten the cable tie tight enough to grip the hose without crushing it, and then tighten it only 3 or 4 notches tighter. The aim of this operation is to reduce the water flow rate, not to stop it completely. If it's only clamping the hose a small amount as instructed above, it won't create much increase in the line pressure. There's a fair bit of pressure in the grouphead, and if you do it too much tighter, it may actually result in water squirting out even faster than before, only with less volume (a bit like a water squirter when you screw it onto the 'stream' setting!). If you basically block it right off, the purpose of the 3 way valve will be nullified, and may not only damage the machine, but will quite likely result in pressurised hot water being retained in the grouphead, which may spray when removing the portafilter. Use with caution, but use your common sense.

Something else you may like to try if the problem is really bad, is to insert a small piece of sponge into the end of the tube. So long as the pressure doesn't blow it out, this will definately fix the problem, but you'll need to remember to remove the sponge and clean it on a weekly basis to prevent it clogging up.


Water dripping from the steam wand
This is another annoying thing about these machines. I don't believe it should be that difficult to fix, but haven't gotten around to this one just yet, sorry!
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