We are still on target to get Londinium I on sale in September
We went to check on progress in Birmingham yesterday and it was a great day
We took two of our roasts up and gave them both a thorough workout
Firstly, the group sits at the correct temperature when idle so its a simple matter of dosing the portafilter and pulling the shot – how cool is that?
Secondly, consecutive shots set new benchmarks in consistency – thermal stability in the group is very high – thermocouple readings of water temperature are it enters the puck are maxing out at about 93C consistently
As with any project plans have changed as the project has progressed
We are now using a Sirai pressure stat instead of a Mater one. Sirai are the benchmark in a large number of commercial espresso machines. The benefit is the Sirai will better handle the switching of the higher current loads that occur on machines fitted with a 110V element
Our original plan was for the pump only to actuate each time the water lever in the boiler fell to the minimum level, running for longer but only infrequently
However testing has revealed that topping up the boiler with a small amount of water as each shot is drawn, and consequently running the element in the boiler for a short time to lift the boiler back to operating pressure gives much thermal management than letting the water level in the boiler drop to the minimum level then adding a much greater volume of water into the boiler to return the water level to maximum, then running the element for a much longer time to get the boiler back to operating pressure – it accentuates the maximum and minimum temperatures and increases recovery times, neither of which are desirable
This change isn’t the issue I feared it might be as the pump is very quiet and if you have espresso cups on top of the machine they do not vibrate around when the pump is on. It also means that while the pump cuts in more frequently, it is running for only a few seconds each time
If you’re wondering why you need a pump at all on a lever espresso machine, let me explain. On an espresso machine that connects to the mains water supply you don’t because as long as the mains line pressure is sufficient it will be able to over come the internal pressure of the boiler of up to say 1.5 bar and load water into the boiler.
On a tank machine you need an electric pump to over come the internal pressure of the boiler, otherwise you can’t get water into the boiler. The only way around this would be to do as they do on an Olympia Cremina and not have a reservoir tank at all, but rather fill the boiler directly. This is acceptable if you are only making espresso, but it pretty much means no water tap and in our view this reduces the appeal of the machine. A hot water tap allows you to make teas, other hot beverages, and soup instantly, without having to boil the kettle. It allows you to roll out an americano or other ‘long’ espresso based beverage. It allows you to heat you cups quickly. It allows you to quickly rinse a cup and re-use it.
Filling a boiler directly presents an opportunity for steam burns and you also have to wait for a full boiler of cold water to get up to temperature. A reservoir also allows us to add in a water softening and filtration cartridge, which i think is a nice refinement.
A reservoir also allows this machine to be suitable for higher throughput environments, such as a restaurant or bar, or indeed a small cafe just starting out where you are unsure of how much demand you will have in the early days, need to minimise your capital outlay, but at the same time need a full fat commercial espresso machine; Londinium I is the perfect machine for this application
We had planned to get an enamel name plate made and attach that to the body of the machine. We are pleased that with some additional investment in capital equipment we can now laser etch the name directly onto the stainless steel body. It will look a bit like this;
Profiles for the hardwood grips have been agreed and we will take the opportunity to make Londinium Espresso tampers in the same hardwood so they match the wooden grips on the machine. The tamper bases will still be in brass.
The glass side panels and clear coat boiler & pipework were able to be seen at the factory yesterday, although they have not yet been fitted to the first machine. There are no technical hurdles to overcome so we are hopeful that these optional extras will also be available when the machine launches in September
We are now fitting the machine with a combination carbon water filter & ion exchange water softener. This will sit inside the water tank and will ensure that your machine is protected from limescale damage and gives you the best espresso possible by eliminating chemicals like chlorine and other impurities from your water. Its true that if you elect to only use a bottled water like Volvic in your machine then this is unnecessary, but Volvic is not available in all countries so we wanted to sell the machine with a complete solution ‘out of the box’ so you can simply plug it in, fill it up, and start making espresso
We are very pleased to tell you that Londinium I will be sold with forged, not cast, chromed brass portafilter holders. in our experience the quality of portafilter castings is poor, and the quality of the chrome even worse – i.e. it flakes off. Not so on Londinium I! What is the benefit of a forged brass portafilter holder to you? Well, if you drop a casting onto a hard floor, for example stone or concrete, it will often break clean in two. A forged brass portafilter will not. Also, the chrome plating on these babies is first class so it won’t flake off – you’d be surprised on how many ‘quality’ espresso machines i have seen this happen on
As mentioned some time ago a kit will be made available for plumbing Londinium I into a mains water supply. Please note that this kit does not bypass or eliminate the water pump. The reason for this is it ensures that the machine will function correctly regardless of how low your water pressure might be. As Londinium I is a machine to be sold worldwide all aspects of its design are about eliminating issues that could be difficult for us to solve remotely. Our approach to the plumb in kit is a good example of this – Londinium I must be a plug & play machine