- Created: Friday, 12 November 2010 20:20
Glenn Szlagowski returns to the Coffeecrew team with this classic take on... The Classic E61!
This reviewer had a Gaggia Classic for several years and it faithfully produced many great shots over that time.
It was time to upgrade. [note: the Gaggia lives on and has a new home]
Based on the review of the Rocket Cellini, that Colin did here, I decided to buy virtually the same machine - the Rocket Giotto Professional. The Giotto has an extra gauge (pump pressure gauge) and a rotary pump versus the Cellini's vibe pump. The Cellini was a reservoir machine and the Giotto Professional is a hard plumbed-in model. Although ›this article is not meant to be a machine review per se, I will go through the process of purchasing, dealing with customer service issues, manufacturer support and first steps with a E61 espresso machine. As I have never had any previous experience with any E61 machine, this qualifies me as a beginner. Errors (there will be plenty and will be entirely mine), please correct me and I will make the necessary mea culpas. Many espresso machines are likely to be purchased on-line these days so I thought I would start off this article with a short discussion of the ins and outs of buying on line.
The Buying Experience
Purchasing by credit card on-line? Be careful about delivering your on-line purchase to another address (a work address, for example) that is not the same as your billing address. The credit card company will certainly decline your purchase because of this. If you give them a heads up and give them these details ahead of time, you should have no problems.
Once the credit card issues were sorted out, my purchase arrived in exactly 5 business days from a vendor some 4,000 km away. It was carefully double boxed and arrived in pristine condition.
There is not very much information about the Giotto Professional on the web but I did come across a review of this exact model at sweetmarias.com. They were running the Giotto from a water jug and based on their advice, I decided to do the same. I would of course, be hard plumbing the machine at some point but the sweetmarias review said drawing water from a jug was not a problem. Or was it?
Low pump pressure and gauge weirdness
I decided to prime the pump (this may not have been strictly necessary) and turned on the toggle switch that powers on the machine. The pump easily draws water and when the auto fill was happy, the pump switched itself off. A first shot indicated a paltry 4.5 BAR pressure on the brew pressure gauge. This definitely didn't look right to me as 9 BAR is pretty much were you should be in pulling a shot. I was getting half that. The sweetmarias review did not mention making any radical adjustments to pump pressure. The vendor where I purchased the machine said the brew gauge might be defective. As the advice from the vendor and other sources were conflicting, I speculated that the brew gauge was perhaps not defective and appeared to be fully functioning. I decided to adjust the rotary pump pressure – a very tight squeeze between the pump and the boiler and managed to turn the adjustment screw that adjusts the pump pressure. Although I managed to turn the screw about a half a turn, it clearly increased my brew pressure from 4.5 BAR to 6.5 Bar. The screw was not accessible enough to adjust any further so some testing had to be done at 6.5 BAR until the unit was plumbed in. I suspect that the Giotto Professional is indeed sensitive to inlet water pressure.
The auto fill is a different story as one morning I saw or rather heard the pump pressure gauge needle fluctuating wildly and battering itself mercilessly against the rest pin stop. Completely normal says the vendor...I beg to differ as the needle moves smoothly when drawing water from the group but not on auto fill. Why the difference?
CSI (Customer Service Issues)
While I was exploring plumb-in options, I decided to do an experiment. In the past, the coffeecrew site has done a number of consumer service stories and I decided to ask five well-known on-line espresso equipment vendors (anonymously) for their expert opinion about why this rotary pump machine machine was getting so low brew pressure out of the box. I also contacted the manufacturer - Rocket of Milan, Italy.
Show me the money!
The responses were disappointing for the most part - if I got one. The manufacturer – Rocket, did not respond to my call for technical assistance.
A UK based espresso equipment retailer that has reviewed the Giotto failed to respond as well. Four North American retailers were also queried including one who had a review of this exact model on their web site.
Three of those vendors sell the Rocket line of espresso machines but asides from idrinkcoffee and chriscoffee, obtaining information was not easy and in some cases – not overly friendly. I will stop right here to make a comment.
Although I am a retailer myself (not coffee equipment related), I get all kinds of emails and yes for a harried store owner whose most precious commodity is time, the inclination is to tell non-customers to go elsewhere for their questions and advice. It is perhaps a short-sighted view as you may be turning away a potential customer; perhaps the customer is not happy with their current retailer, maybe they have moved across country and now live a few blocks away from your store. Maybe they need to upgrade something. Or they're testing you to see if you are worthy of their business. You just never know.
As mentioned, there were a couple of notable exceptions. First off the mark was from Chris N. from ChrisCoffee.com who responded back with an immediate reply. No, he didn't sell the Rocket line of machines but he offered his assistance nonetheless. Very good Chris! Top marks though go to Slawek at www.idrinkcoffee.com (about an hour's drive away from me) for offering me a free checkup (at their expense) potentially saving me a 8,000 km round trip to and from the original vendor. [Note: this was an anonymous query!] There still might be some hope for the world yet… In the end though, no one could or would answer the question: "Is the Rocket Giotto Professional sensitive to inlet water pressure?" The web had no answers to these questions so we will have to break trail once again here at coffeecrew.com.
Water, water everywhere...
I live in a city with extremely hard water. I knew this before purchasing the Giotto but I was prepared to draw water from a jug temporarily before tackling a major plumbing job. Unfortunately the water is so hard here that we decided to install a water softener and a reverse osmosis unit. Therefore, if you are considering buying a hard plumb-in machine make sure you also consider the costs of the various water treatment options as these can easily exceed the cost of your machine! In the end, I decided not to hook up the espresso machine to the new R/O system for the following reasons: R/O water makes (reportedly) poorer tasting espresso, there may or may not be problems with auto fill sensors and fading output water pressure from the R/O accumulator tank (as you draw water) could be a problem with this particular machine. Instead, I decided to go with a conventional carbon filtered, whole house softener setup.
The Giotto basically consists of a boiler partially filled with water heated by a electrical heating element and a bunch of relief valves and tubing. The boiler is under steam pressure and this pressure (or lack thereof) tells the pressurestat to turn the heating element off or on. So with the classic E61 machines, pressure governs the temperature. However in a non E61 espresso machine like the Gaggia Classic, a thermostat (a sensor that reacts to temperature) tells the heating element when to turn off or on.
In a E61 machine like the Giotto, if the machine is cold, the pressurestat closes the electrical contacts to power up the heating element to heat up the water in the boiler. If the pressurestat is set to say, 1.0 BAR of pressure, the heating elements stay on until 1.0 BAR pressure is reached. If less than 1.0 BAR is detected the pressurestat turns on the heating element back on to build up the steam pressure once again. The switching off and on of the heating element by the pressurestat resulted in a fluctuation of between 0.85 BAR and 1.0 BAR on my machine.
The difference between the two readings is called the dead band. At 1.0 BAR of pressure the water temperature in the boiler is just over 250F.
Another fancy electronic circuit keeps the boiler automatically filled with water at about the same level. You will hear the pump switch on occasionally to maintain the level of water if you do a lot of steaming or draw water from the hot water tap. Beginners like me will eventually figure out that you are NOT drawing water directly out of the boiler to produce espresso. The boiler's job is to produce heat and steam and hot water for an occasional Americano.
Water coming out of the group to make espresso is actually separated from the boiler water itself. There is a tube of copper that is immersed in the boiler and as fresh water from an outside source is drawn through the tube, it picks up heat from the super hot boiler water as it travels to your E61 group.
Flush and go or flush and wait
The problem (or advantage) with this HX (heat exchanger) system is that the HX tube is sitting in super hot water and/or steam. Soon, this water will be far too hot.
You don't want to pulling a shot with super hot water flashing off steam! You therefore have to perform a cooling flush to reduce the water temperature to espresso friendly levels. You will get accustomed to seeing the "water dance" as the steam flashes off first and the water stops boiling on the group shower screen.
Now the hardest part for this beginner is deciding when to pull your shot. The flush and go technique means you do a cooling flush and then pull your shot immediately. I presume the temperature is falling in this case. The flush and wait technique means to do a cooling flush and wait until the temperature rebounds to the "ideal" and the pull your shot. Without a thermocouple or Eric group head thermometer, your next best bet is to practice - a lot.
One of the biggest surprises was the very modest steaming ability at the factory setting of 1.0 BAR (top band). At that setting, I found steam production to be unsatisfactory for larger quantities of milk and obtaining proper micro foam was an elusive target. With vendor permission (please check if this might void your warranty), I adjusted the Sirai pressurestat to obtain 1.15 BAR top band. It looks like you'll need 1.15 - 1.20 BAR to effectively swirl around 10 oz of milk in a 20 oz steaming pitcher. Alternatively, you could steam 4 or 5 oz at a time using a smaller 12 oz pitcher. Increasing the boiler pressure a notch higher to 1.2 BAR made a huge difference in steaming ability.
If you do increase BAR pressure you will have to do more cooling flushes because as the pressure in the boiler goes up, so does the water temperature.
Water pressure issues solved
With the plumbers come and gone, the Giotto is now hard plumbed in to the mains. We are drinking softened water that has been charcoal filtered. The pump pressure was now showing close to 11 bars (up from 6.5 BAR pulling from a jug) and I dialed back the rotary pump adjustment screw (about half a turn counter-clockwise) to about 9.5 BAR.
The rotary pump on auto fill no longer sounds like a cement mixer and all is now quiet. The pump pressure gauge needle now moves quietly and more smoothly. So yes, for those experts that don't know beans about this machine the Giotto appears to be sensitive to input water pressure and you should not be running the Giotto from a jug without some cautions. In all likelihood, a Flowjet would likely solve these issues if you have to pull water from a container.
Be careful about pulling water from a jug - the auto fill circuit does not appear to like it. For the experimenters out there, you might try to put a check valve at the end of the intake tube and see if that helps. In any case, the Giotto Professional is happiest being hooked up directly to the water mains. To their credit, the original vendor was in the end, entirely correct about this issue.
If you are a milk drinker and prepare multiple drinks at a time, I would highly recommend that you increase steam pressure to about 1.2 BAR otherwise steam pressure is a bit modest at factory settings. Always adjust the pressurestat with the machine off and unplugged. You do need to turn the adjusting screw quite a few turns (clockwise) to increase boiler pressure significantly. You can safely ignore the “sproing” noises as you are turning the screw. You are compressing a large spring in there. Increasing the pressurestat setting widened the dead band slightly from 0.15 BAR to almost 0.25 BAR.
The Rocket Giotto is sensitive to input water pressure so hooking up to a R/O system may not work satisfactorily as pump pressure will be all over the map depending how much water is in the R/O accumulator tank.
The Giotto Professional model is likely to be discontinued; replaced by the Rocket Evoluzione. It looks identical to the Giotto Professional but has a dual inlet water feature. You can use the integral reservoir or hard plumb it in. Essentially, all of the "jug problems" I encountered are likely to be solved with this new model.
And most importantly, you can descale using the built in reservoir even if the machine is hard plumbed in. The Giotto Professional however is really meant for a permanent hard plumbed in water connection.
The workmanship of the Giotto is top quality (except for the perennial problem of a slightly skewed gauge installation) and component quality is high.
Buy from a vendor who knows everything there is know about the products he or she is selling. Pay extra if you have to. Attention all espresso equipment retailers. Giving free advice is one of the internet's greatest marketing tools. Far cheaper than full colour magazine advertising or fancy web sites.
If you wish to maintain, retain and attract new customers, it is a powerful tool to use and a great way to market your products and services. Owners need to pay at bit more attention to this area especially if you have hired someone to sift through your emails. Hopefully your customer support people aren't losing you too much business. ▪
Next chapter: water debit and water pressure questions, E61 lubrication, Houston - we have a lever problem.