Friday, 5 April 2024

Elektra MicroCasa Leva - brewing notes

 Some notes using the Elektra MCAL

The importance and inter relationship of grind, beans, roast, proper dosing, brew temperature, tamp pressure & pre-infusion can't be underestimated.
Plus the famous single or double Fellini pull.
Timing, tactile feedback, and close observation are critical.

I'm progressing towards a finer and lighter tamp.
A trick is to place a 5cent coin on top of the puck and lock it in. Then unlock. If the coin makes an indentation in the puck then you are over dosing. When I followed this rule, my Elektra shots improved dramatically.
also...
The tamper size is officially 49mm but my tamper is a bit loose. So I tried to thicken the walls a bit by adding clingwrap. ... fills it out to just under 49.5mm. I think the fit is much improved.

The other variable is temperature.
A unique feature of the Elektra Microcasa Leva is its very large group head. It is a effective heatsink. When water first hits the puck, its very hot, but this temp decreases quickly thanks to the group acting like a heatsink.
On the Elektra, if you get the group head to about 80c, keeping the boiler pressure at an average of 1 to 1.25 bars, then the water in the group head should be around 90-95C.





The pic above shows a cold Elektra with two thermometers: 
One measures the outside temp of the group head.
The second, the temp in the puck. 


It takes about 45 to 50 mins for the group head to reach 80C. 
(you can speed this by running some water through the group as its heating up).
I have a teflon boiler to grouphead gasket  that isolates the two (temperature wise). This slows down the initial heating, but improves temperature stability.
This gasket is I think necessary on Microcasa a Leva and Semiautomatica machines made before 1997. 
My machine dates from 1992.
Many thanks to Castorin8 for this and the thermometers











It seems like the outside group head temperature's sweet spot
is 80C. Once you reach that temp, after pulling the first shot, the brew temp will rise quickly past 94C to over 100C which of course isn't what we want. 

The pic on the left is before the first pull.









About to do a second pull. 
Group head temp is 85.7C and the brew temp is 94.6
Third Pull
Group head temp is 89.5C and the brew temp is 101.3C
Way too hot.











If you're planning on pulling more than 3 shots, I think some sort of extra
thermal management is needed. 
Maybe use a heatsink or just turn the machine off and let it cool to below 80C
before doing a second shot. 77C seems to work nicely.

Essentially, the shot now becomes a three-step process:
1) low-pressure pre-infusion with the lever held down, and water slowly entering the puck
2) Moderate-pressure infusion with the lever slowly rising, the puck flooding with water and expanding
3) Full-pressure extraction with the water flowing at the correct rate and temperature through the puck

Basic Fellini Method:
Hold pre-infusion until the first drops have appeared, then gently allow the lever to rise until the liquid emerging isn't just dark and viscous, but has a few crema bubbles.
Then briskly lower the lever, hold it down for 3 seconds to allow the water and puck to stabilize - and finally, release the lever, allowing the shot to complete.

--------------------

Double shot

Aim ...14g in 28-30g out? (30mls)  in 25-30 secs
 experiment with the grind size use a coarser grind? 

Method:
1. Pre-infusion - Hold the lever down. Water is now slowly entering the puck.
    This should last 6-8secs
2. Release lever  when you see the 1st drops starting to appear in your cup.
     If the grind is right , this should occur after the initial 6-8 sec pre-infusion stage.
3. The lever should be travelling up to its starting point by itself.
    If everything is going well it should reach the top at the end of 25-30 secs.

-------------------------

Single shot

7 g coffee in a single (Elektra) basket. The pull was around 25 sec to make about 25g ... 
about 30ml = 1oz  ... 
ratio is about 1:4 ?
This makes a half espresso cup and is fine to my taste. 
I get two to three sips.

One gets great shots from single pulls and single baskets as opposed to the accepted preference for double baskets and double pulls. 

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