Cleaning & Maintenance
Clean brewing equipment is an
absolute necessity for the best coffee flavour, so it's surprising
how often I see various brewers layered with old coffee gunk. The
problem is simple, coffee oils tend to stick to most surfaces, and
when they oxidize they form a tarry coating.
Oxidized coffee oils also have a
horrible rancid taste, which easily contaminates a fresh brew. Prime
culprits are often the filter screens of plungers and moka pots and
the filter holders in drip brewers. All of these can usually be
easily removed for a good scrub with hot water and detergent,
followed by a thorough rinse.
When it comes to espresso
machines, though, the cleaning requirements get a little bit more
complex. First, the most used bits, the portafilter, filter baskets,
shower screen and gasket should be cleaned every day. You can get
special espresso machine cleaners which are mostly trisodium
phosphate, but a good wash in hot water and detergent will do for
the portafilter and baskets. The showerscreen can be wiped with a
soapy sponge, as can the rubber gasket. The gasket can also be
cleaned of grounds with a brush, a bent "kiddy" toothbrush works
Remember to rinse everything
clean; you don't want detergent flavoured coffee!
About once a month the
showerscreen can be removed for cleaning. Use a scotchbrite with detergent to clean the group, and
if the screen is really dirty and the holes are blocked, a wire
brush can work wonders. When you replace the showerscreen, the screw
should only be "finger tight".
E-61 group machines like the
Butterfly don't have flat showerscreens held on by screws. Instead the
screen is part of a "cup" which is held in place by the group gasket.
You can generally lever both the cup and the gasket down with the aid
of a blunt flathead screwdriver against the side, or the tip of a
teaspoon. Both the screen and the gasket can be cleaned.
In between the daily and monthly cleaning machines with solenoids can
be "backflushed" about once a week to clean out the showerscreen and
water path to the solenoid. Sometimes the showerscreen will be so
neglected that no amount of detergent or scrubbing will clean it. In
this case the only way is to hold the screen over a gas flame and burn
the crud out of it, but this will reduce the screen life.
|We see too much of this on machines sent in for repair.
|Sometimes the showerscreen is so clogged water barely flows.
Lelit group and showerscreen
Removed and cleaned
Silvia group and showerscreen
Cleaned (note water distributor washer)
|The E-61 showerscreen and gasket as they come from the group.
|Cup and gasket separated.
HOW TO BACKFLUSH
Silvia Portafilter with blind filter
Lelit Portafilter with blind filter
Make sure machine is properly warmed up, water tank is full and drip tray is in place. Run some hot water through the group.
Place the blind filter basket in the portafilter and add 1/4 teaspoon of Espresso Machine detergent.
Lock the portafilter FIRMLY into the group.
Turn on the brew switch and allow pump to run until it goes quiet, or 15 seconds max. Turn off.
Turn on brew
switch for 3 seconds, then turn off. You should get a whoosh of hot
water and detergent from the valve into the drip tray.
Leave machine alone for 5 minutes, then repeat above.
Another 5 minutes and repeat.
portafilter, run water through group for 5 seconds. Rinse out blind
filter under tap, empty and rinse drip tray then return to machine and
repeat procedure without detergent and without waiting between flushes.
Finally, run 100ml of water out of the group to rinse.
Machines should be descaled about every
6 months or so, more frequently if you're in a hard water area, yearly
in metro Melbourne. You can use expensive commercial descaler or plain
citric acid from the supermarket. Descaling single boiler machines with
tanks is pretty easy, as long as they have brass or stainless steel boilers. First, remove the showerscreen (and the water
spreader washer on the Silvia).
Simply dissolve 10g of citric acid in a cup of
hot water, then add cold water to make the quantity up to a litre.
Replace any water in the tank with the citric acid solution, then
run 300ml (one and a half cups) of water through the group, leaving the machine on.
Wait 20 minutes then run
another 300ml out, this time through the steam wand, then turn the
Empty any remaining solution
from the tank, flush with clean water, refill and run about a litre
of clean water through the machine, alternating between the group
and the steam wand.
Replace the showerscreen (and washer spreader)
and you're ready to brew
Heat exchanger machines like the
laScala butterfly can be a bit more difficult, because the boiler water
and brew water are kept separate. The way I do it makes it pretty
simple, but it does require some minor tool skills.
First, with the machine cold, I
prepare 2.5 litres of descaling solution (as above) and fill the tank
with it. Then I take the top plate off the machine.
Next, I remove the top of the vacuum breaker valve (see pic below) using a socket spanner.
|The vacuum breaker valve is the silvery one on the left.
Then I use a thin hose to syphon all of the water out of the boiler, after which I replace the top of the valve.
With the tank and hoses back in
place, I turn on the machine. The autofill function immediately
activates the pump and fills the boiler with descaling solution.
As soon as the boiler is full, I
start running water from the group, until I can taste that the sour
citric acid is coming through. At this point I stop the water from the
group and wander away for 3 hours or so, leaving the machine on and
hot. At the end of 3 hours I turn off the machine and allow it to cool.
Once cool, it's off with the top of
the valve and syphon out the descaler. I use a small funnel to add
about 0.5 litres of fresh water to the boiler to rinse, then syphon it
out again, then replace the valve top and the top plate.
I refill the water tank with clean
water, turn on the machine to fill the boiler, and once again flush the
group until the water coming through no longer tastes like lemon juice.
As I said at the start, it's really pretty easy, much harder to
describe than to do.
and descaling will certainly make your coffee taste better, but the
main benefit is that the lifespan of your machine will be increased. A
lot. It's a bit like a car, service it regularly and it lasts, neglect
it and it will break down. The majority of the machines we see for
repair are, frankly, filthy. Most of the extremely expensive labour
cost involved in the repairs is incurred during the cleaning. It's a
bit like paying a plumber to clean your toilet, and just as expensive.
rubber ring up inside the group, aka the group gasket, is an absolute
necessity for successful espresso brewing. It holds the pressurized
water in the portafilter and ensures that it's pushed through the
coffee puck. Since it is subject to heat, moisture, mechanical and
hydraulic pressure, the gasket is also usually the first thing to wear
out. So much so that group gaskets are regarded as
"standard consumable items", i.e. stuff the owner is meant to
change on a regular basis.
easiest way to change the gasket on Lelit and other 57mm group machines
is to remove the group collar using a ground down 8mm socket.
|Once removed, it's easy to clean up the group and the collar and replace the gasket.
|Hardened 8mm thick gaskets in 58mm group machines are best extracted using self tapping woodscrews.
|Once the old gasket is out it's time to scrape, scrub and flush the groove before the new gasket goes in.