We were very pleased to see the cabinet for the Bosco lever machine arrive today. Again, the ship-like payload of the A-class came to the rescue, a car that I despise in all other respects including poor build quality, ride, handling, and lack of power. But if you need a city car to perform lorry duties it is in a class of its own. The cabinet is a Infrico MCAF 820. We bought ours from these guys and we're pleased to say they had it in stock and we grilled them on next day delivery and they delivered. And no, they're not mates of ours, we've never meet them. The thing in small business is you always find yourself searching for products that you have no idea who to turn to for, so we were pleased when google threw this cabinet up for consideration. It is purpose built for espresso machines, complete with a hole in the top for water supply and drainage. The construction is 304 stainless (not marine grade 316, but hey) over zinc plate/galvanised steel. We would have preferred an all stainless construction, but this one was a lot less expensive at GBP459 plus VAT. There are a couple of sharp edges that need some attention from our metal file, but all in all we think it is the perfect product for the problem we need to solve and wouldn't hesitate to recommend it. The dimensions are 1050mm(h)x820mm(w)x600mm(d) which is absolutely perfect for the single group Bosco lever espresso machine, and it is also big enough for a 2 group Bosco lever machine. Tomorrow we hope to undertake some major surgery to our plumbing, bringing a copper pipe along the full length of the work bench from the right hand side. We will attach a ball valve at the end, then on to some woven stainless steel flexi to the water filter, then out to the digital volumetric meter, then into the machine. I really can't wait to pull the first shot on the Bosco. No doubt we will need to make some adjustments to our roast, perhaps adding about 10% robusta to develop an Italian style roast, with more weight in the cup.
The KF300 Swissgold filter is without a doubt the best way to make a filter coffee for one person, and probably even for two people; just buy 2 KF300 Swissgold filters and get on with it.
But what to do where you want to make coffee for say 6 people? Well, we have observed that the KF4 12-cup Swissgold filter has not sold nearly as well as the KF300. You will recall our efforts a couple of months ago to purchase and test a number of filter coffee machines from Sainsburys, John Lewis, and Amazon, all of which ended with unacceptable performances, and in almost all cases we discovered that a number of manufacturers have made sneaky minor changes to ensure that the KF4 Swissgold coffee filter no longer fits their machines, if only by millimetres.
With this change a number of these machines now mysteriously sport their own 'permanent' filters. Permanent filters they may be, but if you put them alongside a Swissgold filter the differences are significant. Some manufacturers clearly think that a fine nylon mesh filter meets the definition of 'permanent'. Anyone who has used one will know this isn't the case, the fine nylon mesh is notoriously fragile and becomes increasingly so with age; the heat makes the nylon brittle. More importantly, and this isn't some highly theoretical coffee boffin's objection; passing the coffee through nylon really taints the coffee badly, especially when new. The next group of 'permanent' filters are stainless steel, which are durable but they do impart a metal taint. In the final category you have stainless filters that have been gold anodised and these are the best of the imitations but they are no where near as fine as the Swissgold and the gold plating is not 10 microns thick.
Importantly the Swissgold is not a mesh constructon, but actually a sheet of metal that has had thousands of fine holes precisely cut in it with a laser. When you hold the Swissgold filter up to the light you will appreciate just how precise the process is; none of the holes are ever 'missing', the pattern doesn't vary or wander, the holes are incredibly fine, and thanks to the laser cutting rather than punching the edges of the holes are all perfectly smooth with no raggedness.
What does all this mean in terms of how it improves the taste of your coffee? Simple. Swissgold filters hold back almost every grain of insoluble material yet allow all the colloids which carry the coffee 'taste' through into your cup. The performance difference is significant. For the avoidance of doubt they also out perform paper and cloth filters, eliminate the ongoing cost of filters, and ensure that you never find yourself out of filters yet desperately needing a coffee.
Additionally, almost without exception the filter coffee machines on offer are not calibrated to ensure the correct brew temperature, between 92-96C, and fail to brew fast enough (within say 6 minutes). We also have concerns about selling machines with elements that keep the brewed coffee warm as even the finest brew in the world quickly turns to a vile treacly tar, not dissimilar to instant coffee when left on a hotplate to keep warm. We know these kind of features are sold under the 'convenience' banner by the marketing men but we firmly believe that convenience is a euphemism for sacrificing quality in return for an easy life. If you want convenience Londinium isn't the place for you.
Well, finally we have found a product that delivers after rigorous testing and evaluation. Unfortunately there is a lead time of about 6 weeks on it, so expect to see the product we have identified as the ideal solution in stock here in about a month's time. If you are considering purchasing a high quality filter coffee machine to brew around 10 'nominal' cups we would strongly suggest that you hold off your purchase decision for another month.
We ran the plumbing in copper along the length of the unit from the supply point and terminated to a ball valve. Stainless braided hose from there to the water softener/filter unit (obscured by bench leg). Braid out from filter to connect to the Bosco. We turned it on just before midnight last night and it worked straight out of the box. We dropped down some more 3 pin 13A sockets from the ring - you can never have too many it seems. As you can see the 1 group Bosco conveniently runs on a standard 13A 3 pin plug (black plug, right hand side).
We got the show under way by pulling the pin for a manual fill of the boiler (as filling from empty), wait 1 1/2 - 2 hours for it to really heat up to operating temperature, and off you go.
A very weak image taken some time after 2am this morning just to give you and idea of what made it all worthwhile.
Expectations exceeded even at that hour of the day. For the all arabica specials that we do the Bosco seems to like as much coffee as you can stuff in the basket, with the grind made slightly more coarse to compensate. Extraction times are also more like 45 seconds than 25 seconds as you wait a long time for the last little bit on a spring lever as the pressure from the spring tails off to zero.
Anyway, we are really looking forward to getting back out to the factory this weekend to have a bit more of a play with it. We've even got a 1 week old roast of 80% Brazilian Yellow Bourbon with 20% Java Semeru Estate to try for the first time. The spring lever really does make it child's play to achieve very consistent results shot after shot.
Now I've had a bit of a play I am even more firmly of the view that the Bosco achieves thermal stability in the group in the simplest manner possible; a huge lump of brass that gently dissipates the heat at just the right rate. With the considerably longer 'total extraction time' (from when you pull the lever down until the last drop) that a spring lever imposes on you, coupled with a lump of brass large enough to recast Nelson in Trafalgar Square, thermal stability is imposed upon you by these physical (rather than electronic) parameters. In short, if you pull your shots for the correct extraction time you will not exhaust the thermal absorption of the group.
This means a machine with very limited down time that is easy to fix without the need for a 'factory' technician, and inexpensive parts.
So, what is the downside of a spring lever machine when compared with an electric pump machine? Well, because of the longer 'total extraction time' I think you might find yourself needing a machine with one more group than you might with an electric pump machine to ensure you can meet demand. Allowing you to buy a 2 group and then discovering you really need a 3 group creates a big headache for both parties.
The good news is a 3 group Bosco is considerably less expensive than a 2 group 'high tech' machine and I think you'll find your espresso is better. So the only downside would be if space was at an absolute premium, but if espresso is at the heart of your business we're confident that you'll find the space.
Come and judge for yourself, book a demonstration session on our Bosco today.
You may be surprised to learn that we don't allow ourselves the luxury of just drinking what we would choose at home. Instead we maintain the discipline of rotating around our coffees to ensure we are evaluating them on different days, with or without food, different times of day, and so on.
Over the last couple of weeks I've just stuck with our monsooned Malabar as it is a unique coffee and I really wondered if we were getting the best out of it. I was drinking it at a friend's place sunday evening before last and he made the comment that it produces such a lot of crema, much like a robusta. This got me thinking; that was the problem, there was too much crema, to the point where the taste of the crema was over-whelming the taste of the underlying coffee.
So I've spent some time at home playing with it. My conclusion is to recommend a dose per shot of 6.5g to 7.0g (max), and obviously adjust your grind slightly finer to compensate and keep your extraction time in the 22 to 25 second range (excluding any pre-infusion time). We are also going to roast it fractionally darker (plus 2 degrees fahrenheit). By reducing the amount of coffee we can bring the depth of the crema down to more acceptable levels, which brings the taste back into balance.
Having noted the exceptional crema produced for an arabican coffee the thought has occurred to me that maybe if we blend this monsooned malabar that will assist in preserving the crema of our single origin 100% arabica roasts as they age, without the need to introduce any robusta! If you are a roaster who has already tried this I'd be interested to hear your thoughts. So that's something else we need to try when time permits.
Well, it's early days, but we can say that it's like being given a microscope that magnifies everything in the cup, good and bad. So, while that makes it the best thing we've purchased, it also gives us a lot of work to do in taking our roasts up to the next level. If you are running all arabica roasts (as we generally are) you need to cram in the maximum coffee mass that you can, hard against the shower screen, and adjust the grind to get the extraction time where it needs to be.
He's not a friend, associate, or a friend of a friend. He didn't get a discount or an inducement. He is just a guy in Hungary getting a great deal with 5 bags of fresh Londinium coffee delivered to his door each month.
And dude, if you're reading this, I used Google translator to get an idea of your comments on the Monsoon Malabar and I think you may be over extracting it slightly. Err on the side of under-extraction as it quickly becomes vile if pushed too hard.
10 March 2011 15:20
First impressions of the Bacchi - feel free to use it as a customer recommendation
Review of the Bacchi Espresso Machine.
In this review I will tell you what I think of the Bacchi and the coffee it makes. I'm aiming this review at people ,like me, who have moved on at least one step from a Moka and are wondering: where next? The Bacchi is not so much a machine as a philosophy. As you begin to appreciate the surface so you begin to live in the shoes of its designer. And that is an experience...If you appreciate truly great design then the Bacchi will surprise you.
Normally when we think of coffee machines, things like pumps, solenoids, PID controllers, heat exchangers and pressure gauges come to mind. The Bacchi has none of these things and yet, functions exactly as if it did.
The Bacchi is a stove top machine with a boiler and a steam driven piston. That's it. It is constructed from aluminium and that has been anodised. Which makes it slightly more interesting than stainless steel. The steam which drives the piston is made from a pre-set level of water in the base. Securely seated above the base is the boiler and piston assembly. And on top of that is the group head. All components are held in place by a single bolt secured to the frame at the top.
Now this is where thoughtful design comes into it. In order to achieve a pressure of 9 bar, you need to heat the water in the base to 170 degrees. So you have superheated steam in there. When you hit a pressure of 9 bar you want the water in the boiler to be at 90 degrees. So your heat exchanger is the body of the machine that conducts heat from the (hotter) steam through the body of the machine to the boiler. This little symphony has been orchestrated to perform at between 6 and 7 minutes from a cold start. Use too little heat from the stove and you won't get the pressure. Use to much and the steam is at the right pressure, but the water is too cold. Go shorter than 6 minutes and the coffee is under extracted; go over 7 minutes and the coffee is burnt. So you have to apply sufficient heat in order to raise the pressure and the temperature such that they are both at the optimum within the 6-7 minute window. Therefore you need a control system â and you're it.
You need to experiment with different stove heat settings in order to hit the 6-7 window. But how do you know when the pressure is right? There is a valve that whistles, just like the old kettles, when 9 bar has been reached. So you are listening for the whistle, you are adjusting the energy input and you are measuring the time taken. Quite sophisticated; quite beautiful.
So what does it taste like. Well just before I get to that, there is another crucial element in this equation and that is the fineness of the grind. Too coarse a grind and even if you have everything else right, the coffee will be woeful. Too fine a grind and the machine will choke. So one more task that the controller must perform is to ensure that the shot is delivered in around 25 seconds.
For me this meant getting a new grinder. This what I mean about Bacchi being more of an experience than a machine. So you get the fine grind, the temperature, the pressure and the timing spot on and you are in for a historic treat. Not quite. The final, final aspect to consider is your coffee. If like me you have managed on supermarket beans, you will be both delighted and disgusted. Delighted when that bog standard coffee starts to sing and dance like you never knew was possible; and disgusted when the full horror of stale beans is extracted to perfection in all its gut wrenching glory. This machine gets the flavour out and does n't differentiate between good and bad. So the dull tasteless coffee of the past is revealed now to be deeply, profoundly stale. And you can taste it in techniclour.
But what of freshly roasted beans? When what you get in the cup fits the description of the bean, and does even more in the mouth, then you know you have something very valuable. The Bacchi delivers a diversity of flavour, a fidelity to the bean and reveals a panorama of detail that is just not there in lesser machines.
One last word about the design. The Bacchi has only one moving part. There are no pumps, heat exchangers, pressure or temperature gauges, solenoids or controllers to fail. But the Bacchi incorporates all that functionality in a supremely elegant way, to make truly wonderful coffee.
For Â£260 is there a better machine on the market? I seriously doubt it. But bear in mind you need to spend that again to get a good grinder. Even at Â£520 I still don't believe there is anything that can touch it.
This is the stuff that both Bosco & Olympia use to lubricate the pistons in their lever machines. What's so special about Dow Corning 111? Well it is approved for 'incidental' contact with food (NSF Standard 51 for use in food processing equipment). My interpretation of this US standard is that it is more about ensuring the grease will continue to lubricate the machinery to which it has been applied if the grease is contaminated with food, whereas 'normal' lubricants will often degrade/breakdown and cease to provide adequate lubrication in this situation. It does not mean it is good to eat.
Probably the more relevant standard is that it is also approved for use in situations where it is in contact with water intended for human consumption (NSF Standard 61 for use in potable water applications), which obviously is exactly the situation you have with a lever espresso machine piston.
Dow Corning 111 is described as a general purpose O-ring and valve lubricant. It provides a non-curing moisture barrier; high dielectric strength; moisture and ozone resistance; good thermal, oxidation and chemical stability. It has a heavy consistency and is a translucent white, grease-like silicone paste.
Importantly it has an operating temperature up to 204C.
Where we've found it to be absolute gold is on both cylinder bores (large & small) of the Bacchi. In our view the Bacchi instructions don't really underline the importance of keeping the bores lubricated. To test the health of your Bacchi lift the main piston assembly out of the frame (the engine of the Bacchi if you like), and hold with two hands. Using both thumbs push the piston upwards from the bottom. If it is sticking or binding at any point then it needs some Dow Corning 111 smeared in the thinnest film imaginable on both cylinder bores all the way around, and for the full range of travel. The difference in the smoothness with which the piston in the Bacchi moves after you have undertaken this easiest of maintenance tasks will be like night and day; and so will the taste of your espresso.