THE STRADA CHRONICLES PT4: WHERE WE STAND NOW
I've been using and engineering on the Strada EP for a while now, if you've read my previous posts on what it's like as a machine to use day-to-day then you'll know that whilst I love it, it's not perfect by any stretch. If you haven't read them, humour me and read them now.....
Practical Guide to Strada Husbandry
Up to speed? Good, lets move on by taking a quick look at that Memo;
Scales - lets get the biggie out of the way first. Drip tray scales are a must. It's not essential in my view that they control the shot length on the Strada, but the option for gravimetric dosing would be nice. Most importantly they should be lockable (if you don't want to use them and to protect the load cell), easily carry up to 500g with 0.01g reading and have a very quick Tare function.
Okay, the big one first. Do I still see scales as essential? Not so much. For a start there are much better driptray scales available now than when I wrote the memo, secondly I've had the chance to see several machines with integral scales and see that they raise issues regarding calibration. What we really need is......
Volumetrics - Current flow meters have been shown to be very accurate, see the work by Ben Kaminsky and this video by Matt Perger as evidence. With accurate dosing and good working practices we shouldn't need to rely on scales.
What about better flowmeters though? The current industry standard is good, but by no means excellent. Could we look at more rigorous machining or perhaps utilising flowmeters from other industries, ones where accuracy is more vital?
LCD Display - linking in neatly to the scales is the problem with the current display, its just too small. Time and Weight should be the largest readouts, with good contrast to enable easy and quick reading.
Yup, could still do with better screens
Better Steam wands - when I say better, I just mean easier to use, the current ones are poorly positioned and a little awkward at times, an easy fix. Simply making the wand loop higher over the lever would be a good start. oh and cool touch would be nice.
Steam Wand tips - whilst you're at it, why not include a couple of different steam wand tips, 1/2/3 hole, knife style etc.... It's a common upgrade even though the standard ones are great.
Ditto, the steam wands and tips could stand to be relooked at.
Shower Screens - Hands down the best thing I've done to my Strada. Made a huge difference to the ease of use and consistency from the machine.The standard LM shower screens are old technology and act like it. A precision machine like the Strada deserves precision shower screens.
YES, YES, and thrice YES!
Pressure Control - the current pressure control system using feedback loops creates too many problems, controlling the pump speed by varying the voltage would appear to be a step forward in consistency. see Nick Cho's work on this for details. Click Me.
Still worth looking at we can see that pressure affects flow rate, which affects extraction. I still feel that a constant reliable delivery of pressure is preferable to the system we have currently.
PC interface - being able to save a profile to USB is great, but the software is clunky and annoying. Making this more user friendly with greater access to data logging will be of benefit.
Profile sharing - on the same subject, it should be easy to download a profile from a web based library for use on your machine and vice versa. It's not, because the software doesn't function that way and the website doesn't exist. If they did the Strada would be far more user friendly.
Much of these two have been addressed recently with the release of new editing software (which i was very happy to beta test). More on this in a moment, but I'm still hoping a cloud based profile database in the future though
The Street Team - for a start, the name is a little silly, but then so, to some degree, is the make up of the team. More specifically what appears to be lacking is feedback and input from working baristas with experience of using the machine day-to-day. Obviously that was not possible with the current machine, hence the lack of representation. Now you have the chance to canvas useful feedback from across the world. Big names and engineers are all well and good, but few of them still serve daily using an analogue of the machine they will be trying to improve.
Yup, still valid but the beta testing of the new software shows that this is possible.
The little touches - don't rush it, the small touches like the water mix jog wheel and the name plate on the drip tray make an impression, get these right and the machine as a whole feels and looks better considered.
These count more than ever, design is such a significant part of the speciality coffee scene that to allow the small details to go unaddressed is unacceptable.
Firmware - aha! another new one. These machines are complex and firmware is updated frequently as bugs or improvements are discovered, the ability to easily update the firmware is essential.
So where do we stand now with the Strada?
I've changed both our grinders and driptray scales, both of which help us brew more accurately. The Mythos 1 Climapro is an excellent accompaniment to the Strada, providing consistent and well distributed doses. For scales I've invested in the Acaia scales and can't recommend them highly enough, their speed and accuracy make us far more efficient.
Profile wise, we've looked at a lot of profiles during the software beta test period eventually setting on a peak of 11bar. Its a refinement of our previous profile, keeping to pump constantly moving and reaching max pressure after 11secs. 11bar was arrived at somewhat arbitrarily have tried 9-13bar and settling on the shot that tasted best.
Pleasingly, this is very similar to the Golden Profile presented by Enrico Wurm and Ryan Wilbur in both their new booklet and at Out Of The Box last year. Designed as a catchall profile to maximise extraction and taste in modern espresso roasts, it looks like this;
As you'll notice the new software has a block on pressures below 2.5bar, this is due to the lowest pressure possible being that of your mains line pressure, commonly 2.5-3 bar.
A quirk of the measurement system means that logs files for real time shots show a sharp drop from 2.5/3 to almost 0 after the shot is started. This is due to the sudden release of pressure when you open the solenoid (where the pressure is measured) and a lag time whilst water passes through the system. In the past month we've moved to a modified version of the first profile, topping out @ 8bar rather than 11. The change came from a desire to slow the flow rate, allowing us a modicum more control of the extraction at the end of the shot. Sensory analysis revealed softer more elegant shots and cleaner, less dry finishes. Refractometer analysis showed us hitting comparable ext% for identical brew ratios and shot times. My feeling is that this profile will suit floral Ethiopian coffees very well, but time will tell on this. Rounding out the 4 Profiles we currently have is the Straight 6. This does what is says, runs at 6 bar for 35-40 secs. I tried this after chatting to Max @ Colonna & Smalls as they run this on their Strada/EK43 setup. I didn't find this of benefit for us, the shots were pretty flat, but I can see the benefit of longer shots brewed with the EK.
All of our current profiles can be found by clicking on this link : Strada
To sum up, I'm still happy to say that the Strada sits as one of the premier machines available at the moment. Having had a (very) good look at the competitors, I can say that although some offer improvements in certain areas none of them represent a significant upgrade or present as complete a package at this time.