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Roemer and I tasted some delicious espresso today from Wouter Strietman's ES3 which is almost in production now. A number of custom parts is currently in serial production with the man who is also doing metal work for Kees van der Westen and when they arrive, it will not take long for the first customers to get this latest version of the Strietman range.
What struck me is how open and communicative Strietman is about many details of his design and the learning curve he has been going through since desiging and selling his first Espresso Strietman model. He seems to fit very well in the world of young coffee entrepeneurs, where very few people hold their cards to their chest.
Sometimes he wished he'd had 20 years of experience in the development of prototypes already but luckily he knows people who have and he learns from them. For instance, one senior sharing the huge workshop full of machines and parts to work with wood and metal has been a lifelong prototype / mockup engineer for Philips.
On the floor below one of his work benches, Strietman has three huge classical vintage machines that he has practically stripped to study the work of the earlier espresso machine designers. One machine with a boiler that looks bomb proof has a huge brew head where line pressure is hydraulically converted to 9 bar pressure, another is the E64 brew group and the third an old dual group lever.
On the table, some test samples of copper plates turned into a half ball and a cone, one done using a slow pressure method, "diepdruk" that's time consuming and the other by using a mold and stamping technique. For the top cone of his ES3, the time consuming method is used as it costs about ten thousand Euros to get a mold to create the cones in a quicker fashion.
The workshop is filled with pleasant jazz music from Strietman's sizeable collection of mostly jazz vinyl records. His stereo is on a high plateau above his work space.
It's also a storage for the early ES boxes. Strietman has since learned that he needs bigger boxes and sturdier foam filling to buffer all the abuse that couriers can do to a parcel after they picked it up.
In a corner of his work space is a small collection of early models and parts.
One very early model is a stand up version which can deliver steam too. The bottom half of the brew head is somewhat traditional for a lever, since raising the piston opens a hole in the side for boiler water to flow in. On top of the brew head is a tiny water container which can be filled, by lever action, with hot water that's pressed down into the (partly visible) block heater where it will be suddenly heated to steam which presses out a little steam wand, so milk can be frothed and heated up for cappuccino.
Strietman shows us the detailed work of his piston, which is essentially different from pistons in the La Pavoni or CMA like models (Idrocompresso, LONDINIUM). In a La Pavoni lever, when you lift the piston you first create a little vacuum and air is sucked through the puck in the space above the coffee puck. Then one or more inlet holes for hot water are opened by the retreating seals of the piston and water pours in. The Strietman piston, when raised, immediately allows hot water from the open boiler to come through the center of the piston, downwards on the coffee puck that's tightly packed between basket and dispersion screen.
About these baskets: they are the same 50mm size as the pre-millennium La Pavoni levers and some of these owners may be thrilled to hear that Strietman has ordered the production of several hundreds of special baskets which have much more precise holes. The VST baskets and their quality prompted him to get a similar rate of precision for his ES3.
He showed us one and we were quick to pre-order a few from him. Since I only have one pre-millennium La Pavoni, I will be able to give a few of those away.
Strietman is fascinated by the fact that so much of the espresso technology is still very close to the level of development of the fifties and sixties. It's charming to have this technology lasting all those years basically unchanged, but it also poses a challenge for some to try and outdo the masters, developing a simple machine that takes some of it all a few steps ahead.
Then he makes us some shots of fine espresso. The first cup was absolutely delicious and the others were very good as well but quite different, even though he used the same Ethiopian beans for all the shots. He demonstrated that a slightly finer or coarser grind and a slightly higher or lower temperature setting of the ES3 can make a lot of difference. Some like a shot that tastes like successful shot from a La Pavoni, others prefer a light and fragrant shot that brings to mind specialty filter coffee extraction. Each can be accomplished with the right tweaks in the hands of a maker.