Hello everyone,

Today I purchased a Quick Mill Carola from Chris' Coffee in New York. I thought I would start a thread and post my experience with this machine as a small way to pay back this community for all I have learned over the years as a 'lurker' on this site. Frankly, until now I was not sure I had much to contribute, but after searching for posts on this piece of equipment and finding only minimal information, I thought it is the least I can do to let you know how this goes.

If you want to get straight to the meat of the review, you might want to skip the first couple of posts which focus on the Out-of-the-box experience and my rather tortured attempt at getting my first decent cup out of the machine. Look for the Mechanical Details post. I hope to make an Electrical Details post sometime soon.

Enjoy,
Brad

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I will loosely model my review on the excellent Buyers Guide on the Quick Mill Alexia written by Jeff Sawdy, although I do not have the experience or the equipment to do as good a job as he has done.

A few quick notes about why I chose the Carola-
1. I never drink milk with my coffee in any form, so I am happy with a single-boiler machine and no steaming capability
2. The E61 group head seems to work very well. I have used a commercial machine with this head and I really liked it
3. It has a PID controller built in. This is not mandatory, but frankly, I am not that good at temperature surfing and besides, I am an electrical engineer by trade, so the Carola satisfies both the coffee geek and the electronics geek in me at the same time. [Edit - on Jan 30, 2019. This machine does NOT have a PID, although some of the promotional material on it uses that term. I now believe it has a digital thermostat. At the end of the day, I don't believe this actually makes any difference unless you are using this machine in commercial applications, pulling shot after shot (really??!! with this machine??).]
4. The machine will not see heavy use - I drink an espresso in the morning, and another in the afternoon. Every now and then, I will have one late at night as well, but that is it. My wife does not drink 'frufru coffee' (her term, not mine), so I don't have to worry about having a high-volume machine (although I suspect that, with the E61 and the PID, stability shot-to-shot will be pretty darn good.
5. While I love a good espresso, I am not convinced that you always have to pay a huge amount to get a good cup. For that reason, I have done *everything* I could think of before moving up to a "real" espresso machine. I am almost embarrassed to say it, but my current machine is a Mr. Coffee vibe espresso machine. (Yes - I hear you running shrieking from the room, but hear me out on this). There are SO many variables to making a good cup that I wanted to tackle as many of them as I possibly could before taking the leap and paying >$500 on a machine. I have studied how the pros make espresso, I have talked with the guys at Intelligentsia in Venice, CA, and with the folks here at Octane in Atlanta. I have had espresso from some of the best coffee shops in London, and in Paris. I took all this home (along with some really fresh beans that I know I like), bought three or four hand grinders - sorted through them - kept the one I like (a Porlex), and ditched the rest. I have experimented with absolutely every variable I can think of, and at this point, I can generate a fair cup about 70% of the time, a minimally acceptable cup about 20% of the time, and about 10% of the time it's like 'ewwww - yuck'. About .000000000001% of the time, I get a pretty good cup, and when I do, it is wonderful.

All of this is to say that, after about two years of this, I am taking the step up. I did not want to jump up to a quality machine before I had time to a) figure out what I personally like, and b) to get some feel for what is my fault, and what is the machine's fault. Now that I have made this investment, I suspect I am about to find out that there is a lot more that is my fault, but that's the way it goes. At least I will be removing another set of variables from the espresso nirvana equation.

About the purchasing experience-
I have been aware of Chris' Coffee for a while. A fellow espresso nut friend of mine introduced me to them - he was searching for a wand end that had a different hole configuration from the one his machine came with from the factory. He was very impressed with their customer service and with their product line. Of course, I had been lurking here for a number of years and saw frequent references to them as well.

After doing several months of research I settled on the Carola for all the reasons listed above, so last week I gave them a call. Mary answered the phone and we talked for a bit about the machine, the accessories I would need, and the particulars of payment and shipping. Because of the research I had done up front, I did not have a lot of questions, but Mary was extremely helpful and knew the products they carry like the back of her hand.

I gave myself time over the weekend before deciding to go ahead, but today I decided it is time to take the leap. I called Mary back, we ran through the order, I gave her my details, and that was it. Just the sort of shopping experience the average male is looking for - quick, no hassles, and to the point.

So... the machine is on the way - should be here in three days or so. I am a little concerned about the fact that they ship UPS Ground. Everything I get here that is shipped by UPS looks like it has been run through a trash compactor, so I am anticipating that the outer box will be smashed (not kidding - they must drop-kick this stuff all the way to Atlanta). But some other posts have said that Chris' does a good job with the packing, so that is (somewhat) reassuring. One thing for sure - I will take the cover off to check for loose parts before I put power on it no matter what the box looks like. I have read a post somewhere about boiler connections coming loose in shipment.

My intent is to keep posting to this thread as I work my way through this. One of the things I really appreciated about Jeff's review is that he not only gives us his initial impressions of the machine, but that he also lets us know what he thinks later on after he has gotten used to it. I hope to emulate his method (if I don't get slammed with work and have to back off).

If you have any particular questions about this machine or you want me to test something specific, just let me know. Also, since this is my first real thread on Home Barista, feel free to flame away if I am doing something that is not normally permitted on the forum. After all, we are all new posters at some point (except for the permanent lurkers).

I will post more along with pictures of the trash-compacted shipping box when the machine arrives.

Wish me luck-

The machine has arrived!

If you have ever opened a new Apple product, you know that they have spent *a lot* of time focusing on the OOBE (out-of-the-box experience); that special time between when their product arrives and when you have put all the packaging away and the device is sitting on your desk. So I thought, given how much I was anticipating the arrival of my new Quick Mill Carola, I would start with a summary of my OOBE.

OOBE-
The Quick Mill Carola arrived yesterday, and as you can see from the photo, amazingly Brown seems to have paid attention to the stickers on the box saying, "Fragile". I think this is the first time in several years that I have received something shipped by UPS Ground that has not had a mangled box (the Gods Be Praised!).



As several people have mentioned in other articles, Chris' Coffee does a great job packing their machines and they rightfully request that you save the packing material in case you ever need to ship the machine back for repair. This second photo shows how the shipment was double-boxed with foam spacers between the outer and interior boxes.



I unpacked the box and found that Chris' had packed the other odds-and-ends I had ordered (Rancilio Bottomless PF, tamper, etc.) in the box with the machine. The machine was protected in the inner box by a expanded foam packing block on top, and a plastic bag surrounding the machine itself.

One thing I noted as I unpacked things is that, while Chris' has a manual available on line, it was not shipped with the unit. There was a note included in the box which stressed the importance of following the first-use instructions in the manual carefully to avoid damaging the machine, but no manual, and no mention in the note about where to get it. (Go to http://www.chriscoffee.com, search for the Carola, and look for the tab that says "Resources". The manual is there, along with a diagram of the PID settings and an exploded view with part numbers.)

I removed the machine from the box (wow this thing is *heavy*), and carefully inspected it for signs of damage - all good. Then I took off the cover to check for any loose connections. The cover is held on by four screws, all toward the front of the machine. As soon as the last screw came loose, the cover dropped to the counter with a thud. I removed the cover, and was impressed by how heavy it was. I got my micrometer and measured the thickness of the cover and the trays. The covers and frame measured out at 0.061" or about 16 gauge (1.55mm). The drip tray cover and water reservoir cover measured 0.030" or about 22 gauge (0.76mm).

Continuing my inspection, I noted that the drip tray and the area under the drip tray had stains on them that will not come off, but other than that, the machine is in perfect condition. This is not a big deal because these stains are covered by the drip tray and the drip tray cover, so they are not visible.

I took a number of photos of the interior (posted at the end of this article), and then I tried to reattach the cover. The top front screws went in very easily, but the front bottom screws were misaligned. While I could bend the cover and insert the screws, I decided to take a closer look. I found a fifth case screw at the bottom-back of the unit. As shipped, the screw had been installed in the hole before the cover had been attached.


I removed the screw and reinstalled the cover. With the back screw removed, the front bottom screws lined up perfectly. I tightened everything up and removed the water reservoir, drip tray and drip tray cover. I noted the capacitive water level detector mounted behind the reservoir which is visible through a cutout in the reservoir. This detector shuts down the heater and pump if the water level runs low.

I cleaned the reservoir and trays and reinstalled them, and added water to the reservoir. I then followed the "first use" instructions. 1. Fill the reservoir, 2. Place a bowl under the group, 3. Turn on the machine and raise the brew lever. Allow the pump to run for 30 seconds and then lower the brew lever. 4. Turn off power to the machine. 5. Wait five minutes. Repeat this process two times.

This process ensures that there is water in the boiler and that you don't burn out the element the first time you use the machine.

One note here: In the instructions from Chris', step 2. says, "Power up machine for 30 seconds allowing pump to draw water". What it does not say is to lift the brew lever. If you don't do this, then the pump does not run, but the boiler element is powered up. Unless water has syphoned into the boiler, then if you strictly follow these instructions, you might still burn up your boiler element, thus totally spoiling your OOBE!

Fit and Finish-
A few observations about the fit and finish of the machine. If you are expecting a mass-marketed robotically manufactured machine, you may be disappointed. I strongly suspect that each one of these machines is hand-built. In fact, if you had access to E61 group heads, and had the proper equipment and a TIG welder, you probably could make this machine in your basement. I don't view this as a bad thing, and in fact, I think it is great. It is a little like the difference between a 1965 Ford Mustang and a 2015 Ford Fusion. In a few minutes, you can look under the hood of the Mustang and figure out what everything does. If you look under the hood of the Fusion, all you see is black plastic and chrome, and everything is done by a computer.

That said, at some point I may grab a piece of 1500 grit sandpaper and run it over some of the edges just to round things off a bit. And the drip tray still has sticky flux on it where it was welded at the corners. But overall, I am very pleased with the way it is put together.

Regarding the wiring, the wires inside seem to be reasonably routed away from the hot bits, no wires were close to the case, and wires were zip-tied together, making for a pretty neat installation, overall.

Built-in PID
One thing I want to delve into in more detail at some point is the PID provided with this unit. It uses Italian components, and from my initial inspection, it appears that the PID is mounted on a single PC Board at the back of the machine. A set of dip switches let you select the set point from a low of 195 degrees to a high of 205 degrees, in two-degree increments. There is a large power transistor on the board, which is likely what is used to switch the boiler element on and off, and there are two yellow/orange encapsulated components mounted vertically on the PCB, probably PID Integrated Circuits (ICs). The red heater light on the front of the machine blinks on and off as if it is being controlled by a PID, and the duration of the on/off cycles seems to be dynamic, as you would expect from a PID controller. The PID does not seem to be as "nervous" as the Auber Instruments PID, which seems to have a much more frequent on/off cycle. PIDs can be programmed for different behaviors, and I suspect it is just the case that the cycle times and sensitivities on the controllers are different.

In any case, I plan to draw up a simple schematic for the machine when I get a chance, and while I am doing that, I will pull the controller to see if I can figure out anything else.

At this point, it was pretty late in the day, and I knew it would take some time to dial in the grinder, so I cleaned up my work and stopped for the evening.

[More OOBE photos...]


More in my next post... I attempt to make a cup of coffee!

Brad

Good going Brad. I'll be watching with interest.

That is one beautiful machine! I never saw one before. We're waiting to hear about your output now......

David

This will be an interesting review. Thanks for the detail so far

Making a Cup Of Coffee-


As I mentioned before, the Quick Mill Carola is my first "real" machine. My previous machine was a Mr. Coffee ECMP50-NP. I don't have much to say about this machine that I have not already said. It is a pump, pour-over machine. Temperature control is rough, and although it claims to be a 15 bar machine, in my experience, I never saw it develop that kind of pressure. That said, it was fine as a starter machine at <$100, and using it for two years gave me an opportunity to learn a lot.

My grinder is a Porlex JP-30. I like the Porlex because it has a great set of ceramic burrs, (it seems the Japanese are making really good ceramics these days), and because it fits my hands really well. But it has two issues that I am okay with, but that you might not want to deal with. The first is that it takes about 200 turns of the handle to grind 16 grams of beans (about 1-2 minutes). The second issue is that the grinder has some nubs on the adjusting nut that create steps between grinding settings these steps are too coarse for the Quick Mill. This is easily fixed by exchanging the adjusting nut for a metric stainless steel nylon nut and a stainless washer. I have not made this conversion yet, but when I do, I will make a short post with a picture.

As for the coffee, I just happen to have two coffees in the house, both of which were roasted about two weeks ago. The first is from Monmouth Coffee.

http://www.monmouthcoffee.co.uk

Monmouth is in Borough Market near Big Ben in London. If you are ever in London, you really owe it to yourself to check this place out. I like the SO Brazilian. They don't always have it, but when they do, it is very good. This coffee has primarily a chocolaty taste.

The other coffee is from Has Bean Coffee (love the name!).

http://www.hasbeancoffee.co.uk

Has Bean is an Internet-only roaster in the U.K. Again, the coffee I have is an SO from El Salvador. This coffee has a more "interesting" fruity taste, without much of that creamy chocolaty coffee taste - very different from the Monmouth.

We are ready for the main event.

Going from a cheap machine to the Quick Mill
I will provide a little information about the experience of going from my cheap machine to the Quick Mill in case it helps some others avoid the serious frustration I experienced today. I will provide more technical details on the machine in my next post.

First I checked the water hardness using the strips provided by Chris' Coffee. You dip the test strip in your water for one second, and then let it sit for 20 seconds. Then you compare the color on the test strip with the color blocks on the package. Water in Atlanta is well under 3 grains, so we are good to go.

I filled the machine, attached the portafilter, turned on the machine, and let it sit for an hour.

Since I had no idea of where the grinder would need to be set, I used some cheap beans, expecting that I would need to make several shots before I got in the ball park (boy I had that right!!). I also expected that the new machine would require a finder grind than what I had been using with the previous machine (boy I had that right!!), so I tightened the adjusting nut on the grinder two or three notches. I ground 17 grams of beans and loaded them into the portafilter, put the portafilter on the kitchen scale and tamped to 30 lbs. I gave the tamper a spin to polish the top of the puck, and installed the portafilter on the machine. Time for the moment of truth.

I put the ounce measure under the portafilter, got down so I could see the bottom of the portafilter, got the stopwatch all ready and lifted the brew lever.

I was wanting to start with 17 grams of ground beans, and was looking for 1-1/2 to 2 oz. of espresso, taking somewhere between 24 and 30 seconds for the extraction. Well, I got something a little different.

Five seconds later I lowered the brew lever. The measure was completely full, liquid had blown out of the bottom of the portafilter coating the countertop with a light brown sheen of coffee-colored liquid. Here is a picture of the first "espresso" I made with this machine

[Photo of shot glass]

It was clear I needed a *much* finer grind. I worked my way through the better part of a 1/2 pound of beans, finally cranking the adjusting nut all the way down on the Porlex. I was still getting 2 oz. of liquid in about 10 seconds, with no thickening of the extraction, no changes of color, and coffee coming out all over the bottom of the portafilter. Deep dark depression was setting in. Here is a picture showing how much coffee grounds I had generated at this point.



I was out of cheap coffee, and out of adjustment range on the Porlex. I took a break for lunch and confided my frustrations to my wife, saying that I was not going to buy an expensive electric grinder, so the machine probably had to go back to Chris' Coffee. To say I was not happy is an understatement.

After lunch, I decided to tear down the Porlex to see if I could come up with a solution. The burrs looked fine, but clearly something was not right. I decided to grab a sharp knife and pick the coffee grinds out of each and every flute in both the top and bottom burrs.



After cleaning the burrs and reassembling the grinder, I tightened the adjustment nut all the way tight and turned the handle. The grinder felt completely different - I could feel a slight buzzing feeling - I don't know how else to describe it - as I turned the handle. Also there was a slight ceramic squeaking noise that was not there before.

I broke out the Monmouth coffee, loaded up the grinder and ran another 17 grams through, dosed the portafilter, and attached it to the machine. By now I was *way* past running the stopwatch or measuring the amount of coffee coming out. Putting a bowl under the E61 head, I raised the lever. The pump ran, but... no coffee. The pump continued to run, and continued to run... finally, a whole bunch of beads of dark coffee started to form on the bottom of the portafilter. This was about 35 seconds in. Success!!! (If you call a choke a success . But I was ecstatic. Seems that since I had never had to run the Porlex that fine, coffee grunge had built up on the burrs, keeping it from closing down as finely as I needed for the new machine. I lowered the brew lever, backed off the grinder a notch, ground up another 16 grams, decreased the tamping pressure by about 5 pounds, reinstalled the portafilter, grabbed the stopwatch and lifted the brew lever. Here is the result.



The pump ran for about 4 seconds, and then beads of coffee formed all over the bottom of the portafilter. The flow started, and after about another 4 seconds, the coffee began to turn golden and the streams converged to a single stream. At about 15 seconds the striping of color stopped, and at about 22 seconds, I started to see blonding. I was very excited (not something my 18-year old son likes to see very often). I lowered the brew lever at 24 seconds and breathed a sigh of relief. As I write this now, it seems a little ridiculous to have felt this way over a cup of espresso, but I suspect you understand.

I removed the cup and took a taste. A slightly citrus taste, which faded almost immediately into a chocolaty coffee taste with great body and mouth-feel. Waiting, the taste turned almost sweet before ending with some great mocha notes. I am sure I will make better shots in the future, but I have to say that this was not bad.

So that's it for now. Rather traumatic, but I not only managed to make my first cup of coffee with the machine, but I also managed to troubleshoot the problem and make a pretty darn good cup too.

I think I am going to go sit down now.

Brad

Mechanical Details
The Carola is a single boiler espresso-only machine with an E61 group. The unit measures 12-7/8" tall, 7-15/16" wide, and 15-1/4" deep. Out of that 15-1/4", the main body of the machine measures 9-7/19".



There is a stainless steel cup warming tray measuring 0.030" or about 22 gauge (0.762mm) thick which must be removed in order to fill the machine.



This is really not a problem - if you store the machine on a kitchen countertop under a set of top cabinets, there really is not enough room to store cups on top of the machine anyway.

Removing the cover reveals a sticker which ways:

QUICKMILL Sri - SENAGO
Made in Italy
Mld: 0960-A-XX-A
S.N. 01-39-14-07695
120V - 50/60Hz 850 W

The reservoir is a removable rectangular plastic container measuring 6-1/4" tall, 6-3/8" wide, and 3-3/4" deep. It holds about 1-3/4 quarts of water when full.



Three clear plastic hoses extend into the reservoir. The pump intake hose has a clear plastic filter attached to the end to filter the water before it enters the pump.

On the left front of the machine is a single on/off power switch, a green power light, and a red heater light.



On the right front of the machine is a 0-16 bar pressure gage labeled "Quick Mill". The face of the gauge is white with black lettering. The band from 8-10 bar is colored green, and the band from 10-16 bar is colored red.



The E61 group feels very prominent in this machine, probably because of the chassis' narrow width. The brew lever sits to the right of the group, and attached to the brew lever shaft is a cam which actuates the machine's pump through a black-capped microswitch. I have seen the debates about whether the brew lever on the E61 group has two or three positions. All I can report is that on this machine, there is a definite feeling of a detent position as you raise the brew lever prior to when it engages the microswitch.



The case, which I measured at 0.061" thick or about 16 gauge (1.55mm), is made out of stainless steel and is attached to the frame by five screws; two at the front on each side, and one in the back. It is a very good idea to have a towel under the machine when you remove the cover, because you might scratch your countertop if the cover unexpectedly drops on to the counter when you remove the last screw.

Once the cover is removed, there is a sturdy interior frame which is made of 22 gauge steel, upon which the water reservoir sits. This frame attaches to the front panel by two Philips screws at the front/top of the machine, and the case screw at the back. One note regarding these screws that shows that Quick Mill pays attention to details - these two screws seat into blind nuts embedded in the frame. I am guessing this is because the frame is thinner than the case, where the screw holes have simply been tapped.



If you remove the three clear hoses from the interior frame and remove the two screws I just mentioned, you get a Most Excellent reward. The machine neatly lays out in two pieces! (Thank you to whoever designed this machine.)



This provides excellent access to all the internal components. In fact, you can power up the machine in this configuration, since you do not have to disconnect anything to separate the frame from the front panel.

Opening the machine reveals the boiler, nestled in a bottom support frame - the boiler is not physically mounted to this frame, but the frame supports it, keeping the boiler from being supported solely by its fittings.



There are three boiler fittings. The feed running up to the group, a group return, and a water feed from the vibe pump. The water pressure adjustment is easily accessible at the output of the vibe pump.



A resettable over-temp sensor is screwed into the top of the boiler, and a ground wire runs directly from the boiler body to the ground lug of the power connector.



There are two other boiler connections - a temperature sensor for the PID unit, and a pressure connection for the front-panel pressure gauge.



The boiler is wrapped in foil insulation, and the holes cut in the insulation for the water fittings were well crafted, not just hacked out.

Wires are neatly zip-tied together and are held out of the way of the boiler. The electronics consist of an Italian manufactured PID circuit board mounted on four plastic stand-offs at the back rear of the machine,



a capacitive water level detector module mounted on a shelf above the PID,



which is connected to the capacitative sensor which is mounted next to the water reservoir.



and a pump relay mounted to the detachable cover.



Note that this relay is a double-pole relay, but Quick Mill only uses the Common and Normally Open contacts.

The vibratory pump is mounted to the bottom of the chassis with two rubber mounts, one at each end of the pump; this reduces noise transmitted from the pump to the chassis substantially. Power to the pump is routed through a sensor which cuts power to the pump if it runs for an extended period of time.



The drip tray cover has a series of holes approximately 1/4" in diameter through which liquids pass into a drip tray positioned below. There is a 7/8" diameter hole at the back of the cover to allow the discharge from the bottom of the E61 group to rapidly pass through the cover and into the tray itself.



Removing the drip tray cover reveals a 1-5/8" tall, 7-1/2" wide and 5-3/4" deep drip tray. As I noted before, the finish on the drip tray corners is a little rough, and the exterior surface of the drip tray at the corners was sticky with flux.



The machine runs on a 110 volt 15 amp conventional electrical circuit. The power cord is not permanently wired to the unit. Instead, there is a IEC 320 C14 connector (similar to a computer power supply) on the back of the machine. This allows you to easily replace the stock cord with one that is an appropriate length for your installation. My machine shipped with a massive 8' long, 3/8" diameter cord. I have the machine situated about 10" from a counter top outlet, so that is a lot of cord to hide behind the machine. I ordered a one foot long cord from Amazon for about $2.50. The IEC60320 specification says that this connector is rated for 10 amps. When the heater is on, my amprobe measures about 6-1/2 amps, so the machine is pulling well below the maximum current for the C14 connector.



On the bottom of the machine, there are four black rubber feet, attached with M5 nylock screws. The feet leave marks on my counter top, so I will be changing these in the near future. The feet get a very good grip on the counter top, and the machine does not scoot around when I am securing the portafilter.



There is a removable cover which provides access to the boiler terminals, and in a very nice touch, it is held on with two M4 cap nuts, preventing you from accidentally scratching your countertop with bare 4mm screw ends.



Looking through the hole in the bottom, you can see the heater element and the bottom of the boiler. It appears that the heating element is removable, which is great news if you accidentally run your boiler dry and burn out the element.



One note about putting the machine back together. I put the interior frame back in the machine, screwed down the two screws at the top of the frame, put the four front cover screws back in, and then could not get the single screw at the bottom in the back to go in straight. Looking in the hole at the back of the unit, I could see that the interior frame was mis-aligned. I took the machine apart and found that the base of one of the PID standoffs was keeping the frame from seating properly because it was rotated 90 degrees. I rotated the standoff 90 degrees and this allowed the interior frame to sit flush at the back of the unit.



I checked the alignment and everything was perfect.

While I had the machine open, I drew out an electrical schematic which I will post the next, along with an electrical 'theory of operation'. Hopefully this will help anyone who has electrical problems with the machine.

For now, I think I will go make myself a cup of espresso.

The water pressure adjustment is easily accessible at the output of the vibe pump.

Really great review and pics.

The brew pressure adjustment is an OPV where the water enters the boiler - very similar, if not identical, to the Alexia. The first brass "gizmo" attached to the pump's snout is a deaeration/pump priming valve. The second white plastic "gizmo" is a device designed to reduce the pump pulsations and thus make the pump quieter than the typical install.

Thanks Eric,

I think you are right - this machine is very close to the Alexia. One area where I believe they differ (other than, obviously, the Alexia has a steam wand and the Carola does not) is in the details of the drip tray and cover. Another is the PID. This machine does not have a temperature display and the PID settings are adjusted by removing a cover on the back of the machine and setting several dip switches. To me, the vibe pump, the relay, the over temp sensor and a number of other things seem to be very similar.

One question - what is an OPV?

Brad