it is worth pointing out that the significantly shorter distance from the boiler to shower screen on the Cremina group means that once the first espresso has been drawn from the machine it stays very close to operating temperature whilst left at idle. It will be slightly on the cool side, but the clever design of the group allows you to circulate water through the group and back to the boiler without dispensing any water through the shower screen. To do this raise the lever arm to just above a horizontal position (if you go too high water will obviously gush from the shower screen), and then simply return it to the resting position. One of these partial upwards and down movements will be sufficient to bring the group up to operating temperature.
Here's a thought that many of you will already know, but some may not, so bear with me.
The most common design of domestic espresso machine uses an electric pump to shift cold water from the reservoir through a pipe that runs through the inside of the boiler to heat the water to the correct temperature for espresso. Unsurprisingly this design is known as a heat exchanger, often expressed as simply 'HX'. When a machine of this design is on but not being used the water in the HX quickly rises to the temperature of the water in the surrounding boiler that the HX pipe is running through, which is too hot for espresso. For this reason a cooling flush of 5 or 6 seconds is required if the machine has been standing idle for more than a minute or so. If the pump on these machines is run for too long the HX will struggle to heat the water fast enough and at some point it will become too cold for correct espresso preparation.
The simple lever espresso machines that Londinium Espresso offer differ not just in the absence of an electric pump to drive the water through the coffee, but also in the way in which they regulate the temperature of the water prior to it making contact with the coffee.
Both the Bosco machines and the Olympia Cremina use what is known as a dipper design. That simply means that when you move the lever, raising the piston in the group, which allows water to exit the boiler as a result of the steam pressure in the head space at the top of the boiler forcing down on the water in the boiler and pushing it out through the open port. Here lies the fundamental difference between a HX design and a dipper.
As outlined above, HX machines sit too hot at idle, yet run cooler and cooler if they are used continuously. In contrast, dipper designs sit too cool at idle yet run hotter and hotter if you draw enough water through the group to exhaust the thermal capacity of the group. So it can be seen that both designs have their limitations.
The extent to which the simple dipper design is successful in delivering water at the correct temperature to the ground coffee depends on the ability of the group to bring the water as it exits the boiler at well over 100C down to say 92-94C by the time it makes contact with the coffee. To achieve this you want the group made from a material with high thermal conductivity (chrome plated brass) and lots of it (to create a heat sink). It also means the first shot (on a small group like the cremina) or the first two shots (on a monster full commercial group like the Bosco) will be too cold to produce optimal espresso if the group has not been used for a while.
Testament to the quality of the design of the small group on the Olympia Cremina is that you can pull six double shots before the group's thermal capacity is reached and the water becomes too hot to make optimal espresso. On the Bosco the significantly greater mass of the group means it is difficult to saturate the thermal capacity of the group, assuming you have the boiler pressure set correctly (1.2 bar). The length of time it takes for the shot to be extracted, to move the cups away, remove the portafilter, knock out, wash, wipe, reload, tamp, and reattach to the group is sufficient for the group to recover its thermal capacity, ensuring the group does not deliver water that is too hot to make optimal espresso.
The important point is that under no circumstances should you try and bring the group of the dipper design up to temperature after it has been sitting idle by embarking on what I call 'open port flushing'. That is to say, by simply moving the lever on the group and allowing water to gush from the boiler unrestricted. This will almost instantly exhaust the thermal capacity of the group as a result of the high flow rate that occurs through the group when no coffee is in the portafilter to regulate the flow. Rapid flushing of water at boiler temperature through the group not only over heats the metal immediately surrounding the bore in the group but also leaves cold spots in the group.
This is how bad experiences with dipper design machines start; open port flushing rituals that are appropriate for HX designs but ruinous on dippers. Please desist if you have a dipper machine and astound yourself with the improvement that arises in your espresso.The correct way to bring the group in a dipper design is to use the stale coffee that is sitting in the internals of your grinder (a double shot dose). It will have dried out a bit and the water exiting the group will be cooler than it needs to be so expect it to gush through a bit faster than it should.
On domestic grinders and groups the next dose of coffee out of your grinder will be fresh and the water will be hitting your coffee at the correct temperature so the second one should be good to drink. This approach not only ensures the bore is at the correct operating temperature but that the entire group has had a chance to slowly heat through evenly, eliminating any cold spots in the group.If you are running a commercial setup with say a mazzer robur and Bosco then the robur will need to serve two doubles before it clears the stale grinds and the big Bosco groups will need two double shots to get up to temperature, so they pair up rather well.
So if you are fortunate enough to be enjoying the design purity of a dipper espresso machine (which includes for example the ubiquitous La Pavoni lever machines) be sure to quit open port flushing. Try it, and taste the difference.
If you over heat the group on a dipper machine just leave it to rest for 15 minutes and come back to it, but if you follow the procedure outlined above it should never occur at startup.
It is my firm view that open port flushing on dipper designs is more to blame for the horror stories you hear of people struggling to get a good shot from them than effects of all other poor techniques combined.
We have for sale two evaluation machines
1 x Ponte Vecchio Lusso, 2 group, stainless steel body
1 x Ponte Vecchio Export, 1 group, chrome body
Both machines about 3 months old and only used with care, and therefore in almost new condition
Email or call if you are interested
Slow Food International is a global, grassroots organisation with supporters in 150 countries that links the pleasure of food with a commitment to the community and the environment. A nonprofit, member-supported association, with charitable educational programmes, Slow Food was formed in Italy in 1989 by Carlo Petrini to counter the rise of fast food and fast life.
Slow Food UK
Slow Food UK supports a network of 50 local volunteer-led groups throughout the UK who promote and enjoy the Slow Food way of life within their communities, organising a range of events for their local members. Over the course of the year Slow Food UK will connect with over 30,000 people via membership communities and educational programmes.
Slow Food UK encourage people to choose nutritious food, from sustainable, local sources which tastes great through the national educational programmes that they manage: Slow Food Baby (nutritionally develop babiesâ taste buds), The Taste Adventure (children exploring food via their five senses), Slow Food on Campus (university and college students â creating tomorrowâ s leaders in developing our food system), Slow Food Wisdom (rediscovering British food traditions and recipes) and The Ark of Taste (safeguarding endangered and traditional foods). For more information visit www.slowfood.org.uk
Slowfood UK also run The Taste Space retail shop in Nealâ s Yard, London which opened in June 2011 â the first of its kind for the Slow Food organisation. It is a great opportunity for you to drop by to see some of the unique foods produced by Slow Food UK members and learn more about Slow Food UK.
This grinder which we have owned from new has only been used lightly, as you will see when you inspect the burrs. The hopper does have scuffs on it as shown in the images below and the top plate has been engraved with the word 'filter', as shown. This grinder is in excellent condition. Our strong preference is to sell it to someone who can come and inspect it at our premises to satisfy themselves as to its condition and suitability for their intended use. We are selling it as we have accumulated more grinders than we need. 240V. UK plug. GBP300. A cost effective 'doser-less' grinder.
Get along to Exhibit design store and taste the difference of hand drawn espresso from their magnificent two group Bosco spring lever espresso machine.
Olympia Express are exhibiting at SCP East for the London Design Festival 2011. The Design Department store is an exhibition set up within the SCP East store for the London Design Festival. All items on show are available to purchase. This event is the UK launch of a specially chosen collection of design products from around the world, including furniture, lighting, accessories, textiles, and rugs. SCP East is part of the Shoreditch Design Triangle.
The London Design Festival is now on, running from 17 to 25 September 2011.
Get yourself down to SCP East tomorrow to discover the capabilities of Olympia espresso equipment where it really matters; in the cup
SCP East are open 0930 to 2000 monday to friday, 0930 to 1800 saturday, 1100 to 1700 sunday
Nearest tube for most people is likely to be Old Street (Northern Line) exiting from the eastern exit, Exit 2
SCP East
135-139 Curtain Road
London EC2A 3BX
ENGLAND
I note with customer enquiries the persistent suspicion as to whether the Bacchi can possibly deliver real espresso like a commercial machine. I have no hesitation in saying "It does!".
Having recently returned from taking the Bacchi on a two week holiday where I used it multiple times a day I think even more highly of it than I did before.
There are only two conditions I can apply to the Bacchi. One, it is not a machine for meeting the needs of more than two people. Second, and I am tempted to write this in bold 48 point in response to all the clowns grizzling on the many coffee forums around the net, the base on the Bacchi only distorts if you place it on the heat without putting 30mL of water in the base. A bit like forgetting to put water in the radiator of your car really.
We have now sold many many Bacchi, and whilst it is true that a number of customers have come back saying the base plate has distorted, they have all without exception eventually come clean and admitted that they forgot to put water in it, or placed it on the heat and went off to do something else and completely forgot about the Bacchi on the heat. The good news is you can replace the base for a nominal cost and your Bacchi is as good as new again.
I am unaware of any instance where a Bacchi has failed other than as a result of the misuse described above.
Below are two unedited clips of our Bacchi in action on our recent holiday. The espresso in the first clip is over extracted, I know. In the second clip the extraction is pretty good, although I failed to capture the commencement of the extraction. On the Bacchi you can fine tune the extraction time by how far you open the release tap on the machine.
All taken on a well used 3GS iPhone so I'm afraid the quality isn't wonderful in the low-ish lighting.
This elegant Bosco lever espresso machine is currently being installed in central London, allowing you to experience the Bosco difference first-hand from September 2011.
