My dilemma is this: I have a lovely Grimac Mini (E61 group head, hx machine, 1.8L. boiler, rescued from hard rubbish (yes, really) that makes superb coffee. Rich, thick shots, all I need to do is run a little cold water over the brew head to bring the temp down a bit before extraction.
The one drawback for me is that it's not plumbed in. A kitchen renovation gave me the opportunity to provide an appropriately filtered water supply and drain. I bought myself a metal-bodied vibratory pump as per the plumbed-in model in preparation for converting it to plumbed-in operation, then checked the diagram for the plumbed-in model and saw that a proper conversion is more complex than I thought.
THEN, I saw a Faema E98 A-1 Diplomat volumetric machine with new rotary pump on ebay, ready to be plumbed in, for pretty much what I thought I could get for the Grimac- a no-brainer swap, yes? And I wouldn't have to have to bother converting the Grimac. A week later, I had the Faema on my kitchen bench, plumbed in and pulling shots. Awful, awful shots- thin & sour. Since then, I've tried adjusting the pump pressure down (this helped, it was way too high) and adjusting the pressurestat, but the results are still awful. Thin & sour, or thin & bitter. I just can't get a happy medium.
My question to the coffeesnobs cognoscenti is this: Do I persevere with the Faema? Will I ever be able to coax decent coffee from it? I'm prepared to invest in either building a scace-type device to really see what's going on, or a visit from a reputable mechanic who has one himself. Or is it simply that the Faema will never be able to produce shots as good as an E61-type machine, with the inbuilt pre-infusion effect that the E98 lacks?
Looking forward to your reasoned and erudite comments, and ridiculous offers for the Faema.
Yes, any comparison between the two machines is going to be completely UNfair unless they are both working at optimum at the time of the comparison.
There is no reason why they both (in an ideal world) shouldnt be producing great coffee so in the end in terms of choosing which one to keep, I think it will come down to the different features offered by each machine (& their relative importance to you) rather than the brew quality. I would say, decide which one you want to keep based on the total package of each.
If you decide on the faema, then I am afraid you may have to budget to take it in for service.
At present, the flavour of the Grimac outweighs the undeniable convenience of the Faema. If however the Faema can produce shots equal in quality to the Grimac, I'd prefer to keep it, even though it may take some $$ to get it fixed. I suppose I'm just looking for reassurance that money spent on it won't be wasted for the same reason that sending my Lancer to the mechanic for a tune isn't going to make it equal to a Ferrari.
Anyone prepared to hazard a guess as to what the problem might be?
Impossible to make any obervations without seeing the "offending machine" on the bench in front of me.
However there is one (very important) thing.....are you re adjusating the grinder (and your technique) each time you change from one machine to the other? The optimum grinder setting and operator technique for one machine, is not necessarily the same for the other. This is easily demonstrated in cafe situations, where it is not uncommon to take a grinder from one situation and place it in another. They (grinders) invariably require re adjustment to suit the "new" machine.
Hope that helps.
I've never been one much to adjust things blind...without a gauge, how do you know the pressure was too high, and how do you know where the pressure is now? Yeah I know I know, lots of friendly people on the web will tell you how to time flow/volume for a particular pressure, but how do you know its all correct for your model / type of water pump, motor and machine without a gauge?
My approach first up would have been to determine the right dose / grind / operator technique (in that order) to get the best possible brew from the machine as was (with one only type of beans), and work from there. Many "coffee problems" are actually caused by operators not properly understanding the proper relationship of the grinder and their technique to the machine first up, irrespective of where the bypass pressure is set to....
Otherwise I am afraid it will be for the service tech.
"all I need to do is run a little cold water over the brew head to bring the temp down a bit before extraction."
hhmm, interesting cooling flush method. i think most folks run some water through until the water settles down and behaves nicely.
brew pressure is pretty important factor
so too is your dose level. are you dosing too high on the faema, causing a fractured puck and channelling?
"Interesting cooling flush method" = "extreme" cooling flush method, shouldnt be required (that's like saying.....I have to pour a bucket of hot water over the engine of my car before it will start in the morning.....it may well start & run that way, but it shouldnt be required).
Brew pressure IS a pretty important factor, but in this case without a guage it's a moot point and machines can still make a reasonable coffee when running at higher than "spec' pressure when all else is being done right especially dose-grind-tamp;
Dose level IS extremely important. It affects what will become the correct grind / settle / tamp technique for an individual machine, which may be different to what is the "correct grind", for another. There is no one correct dose-grind-tamp to suit all, you work out what is the best way of doing things for each set up.
Hope that helps.