I hope & pray that after all of these reviews on ALEXIA are done, you EXPERTS can tell us if we need the PID kit or not to make consistently great shots.
A few of you have suggested this machine is a perfect upgrade from Silvia so I am watching this very closely. Thanks for the hard work!

Beavis wrote:I hope & pray that after all of these reviews on ALEXIA are done, you EXPERTS can tell us if we need the PID kit or not to make CONSISTENTLY great shots.

Emphasis added to the above. If you want CONSISTENCY, I think the PID is a valuable option. That said, the PID does nothing to increase the machine's overall maximum potential. Let me explain why I think that is the case....

HB wrote:Note: This evaluation model is a slightly modified version of the PID kit offered by Jim Gallt / Chris' Coffee. When I did a few quick measurements of the original PID configuration, I noted temperatures would trend upwards. I noticed this same tendency with my PID'd Amica and added a manual cutoff of the heating element to reduce overshoot; I figured it might improve on the Alexia's already impressive performance. I contacted Jim about this and he sent me a cutoff relay for the heating element whenever the pump was engaged. While the difference in intrashot brew temperature is likely beyond the abilities of mere mortals to taste, the cutoff relay has the added benefit of eliminating the "aaaa-eeee-aaaa-eeee" sound of the pump as the PID cycles the heating element on and off during an extraction. At this price point, I believe the enhanced usability and elimination of the pump pressure zig-zap due to heating element cycling is worth it, but Chris/Jim haven't decided on the cost of this option.

OK, so on Dan's machine, when he lifts the levetta lever, the heater is cut out and the PID is doing NOTHING! It is not trying to compensate for incoming cold water, it's not trying to maintain the current set point, it is totally removed from the equation. That means that the intrashot flat profile is coming primarily from the machine's design; the boiler size, grouphead size and temp, water mixing, over (brew) temperature condition of boiler water, etc.

Now, sure I think it helps that the boiler has been sitting at a flat line temperature for some time prior to the lifting the lever. This likely helps control (or at least make consistent) stratification of temperature and eddies in the boiler, and perhaps most importantly control the grouphead temperature.

So on the stock machine, you have the same design, so you should have the same intershot potential. The trick is, you don't know the current boiler temp, and you don't know what the grouphead temperature is. You can only try to develop a routine that improves consistency, and that is developing some sort of temperature surfing routine. The downside to surfing is that you either wait and watch the heater light, or you doing something to force the heater on, use extra water and wait again. (Now Eric's adapter would take care of knowing the grouphead temperature, but would you also need to monitor the boiler?)

On a related note, I have been having a conversation offline with Gary. Gary has pointed me to a thread on CG, where he surfs the boiler and the grouphead temperature with a copper block on an Isomac Zaffiro. See Control of E61 group temperature using copper cooling block.

Beavis wrote:I hope & pray that after all of these reviews on ALEXIA are done, you EXPERTS can tell us if we need the PID kit or not to make consistently great shots.
A few of you have suggested this machine is a perfect upgrade from Silvia so I am watching this very closely. Thanks for the hard work!

I don't care much about intra-shot temperature stability, as long as the temperature stays within a reasonable range.

The most important advantage of the PID is easy and precise adjustablity. I adjust temperature for each blend (I keep a record of my preferences) and sometimes adjust while the coffee "ages."

Quick Mill Alexia - PID Use, Part 1


Quick Mill Alexia - PID controller display; current temp (left), set value (SV) (right)

PID Kit Alexia Usage Instructions

The PID controller included in the Alexia kit is pre-tuned for the Alexia, and a set value (SV) of 230°F. No further tuning or programming* is required. The SV is indicated on the controller by the smaller green numbers on the right of the PID display. The current boiler temperature is indicated by the large red numbers to the left. The PID kit manual indicates that the SV of 230°F should correspond to a brew temperature of 203°F or 204°F for most machines. It also suggests lowering the SV by taste for lower brew temperatures and that actual brew temperature is typically 26°F lower than the SV.

(*- FYI, a full user's manual for the Watlow controller was included in the kit for those that wish to learn more about using and programming the PID controller.)

Here are the recommended PID machine usage instructions included in the kit:

• Warm machine with portafilter installed for 35 minutes minimum,
• Pull a warming flush of ~3 ounces,
• Remove portafilter, wipe dry and build shot,
• Pull your shot within 1 to 3 minutes of doing the warming flush,
• Pull a warming flush if the machine has been idle for 5 minutes or more

These instructions are given with the caveat that following this procedure will give the most consistent results. It is also suggested that the warming flush can be skipped with the understanding that shots pulled in near succession will be 1°F to 2°F higher than the first shot.

PID Set Value (SV)

I played with the thermofilter all day on Sunday and pulled 40+ simulated shots (and probably only had 3 to drink ).

I spent a lot of time pulling shots at different set values (SV). The setpoint is simply changed by pushing the up/down arrows to the right side of the PID controller interface. My shot spacing varied, but it was never less than a 2 minute recovery between shots (interruptions from little ones sometimes changed my shot spacing ).

I had started out with the idea of using a rather strict procedure:

• Giving some time for the boiler to stabilize, 10 minutes or so,
• Pull a 3 ounce flush,
• Wait 2 minutes,
• Pull all my shots equally spaced apart at 2 or 3 minutes (from end of previous shot),
• Measure temp via Scace for a 30 second simulated shot.

As I got into doing this, I was seeing that it didn't really make much of a difference what I did, so I started to use this simpler procedure:

• Wait 10 minutes between set point changes (sometimes longer),
• Pull a warming flush of only 1-2 ounce flush between set points or if the machine sat idle for some long period,
• Pull all my shots at fairly random intervals, never less than 2 minutes apart (from end of previous shot),
• Before pulling a simulated shot, I dumped the Scace portafilter, ran the pump just long enough for a few drops to come out of the group's dispersion screen,
• Measure temp via Scace for a 30 second simulated shot.

I did not datalog these shots (I have to be laptop tethered to do that), I just monitored the maximum temperature obtained intrashot. Just as a reminder, my review machine does not have the heater cutoff relay that Dan has installed. What I visually observe on most simulated shots is a rise to a peak temperature fairly early, a small fall of about 0.5-0.8°F, and then usually finish again at or near the same peak temperature at 30 seconds.

The Set Value and Brew Temp (°F) data is shown in the table below. The readings for a given setpoint (SV) are sequential as the shots were pulled, but I did not simply move up the SV in an ascending order. I bounced around a bit up and down for the SV. Glancing at the data I think you will see that any outliers are of ~1°F difference, I think that my slightly simpler procedures should suffice for most people.

And assuming the SV to brew temperature relationship is linear, I get the the trendline seen in the graph below. This means my PID to brew temperature offset is approximately 22°F

Temperature Profile

Here is a chart and table for two datalogged shots with a PID SV=223°F. I am using a Scace (v1) thermofilter device and an Extech meter. I did a series of 6 test shots at this set point, these are the only two that were logged. I watched the maximum temperature reached in the series of six shots, in this case:

202°F, 201.4°F, 201.5°F, 201.5°F, 201°F, 201.3°F

In the next installment, I will post intershot performance with a more rigorous testing protocol, as well as some longer shots.

Thanks, Jeff. I'd be very interested in the effects of varying the warm-up flushes (say from 1/2 to 3 oz.) and then eliminating them altogether.

Marshall wrote:Thanks, Jeff. I'd be very interested in the effects of varying the warm-up flushes (say from 1/2 to 3 oz.) and then eliminating them altogether.

Marshall, this graph may show a little of what you ask. For this series, I had a 7 minute idle period before the first shot (recall the PID kit manual suggests a warming flush if idle for 5 minutes or more). IIRC, I did a ~1.5 ounce warming flush 2 minutes prior to the series. For each of these I did a "start dump" of the Scace, "spritzed" the group for just a few drops, locked in the Scace and pulled the simulated shot. The first shot tracks a bit cooler, but only by 0.5 - 0.7°F, the next two shots hug each other pretty nicely.

And the data:

At a minimum, I will try to see what happens with no warming flush from idle.

Curious if that 22-23 degree difference from the SV to the group head could be different on different Alexias with different PIDs? Are you all using the exact same Alexia for these tests?
Dan's machine was 24 degrees different...The Watlow kit says 26 degrees.
I know that the PID kit and the range (4 degrees (26-22=4)) probably is nothing to worry about but it goes right back to the same issue of trying to pull different blends at different precisely different temperatures. It's not a perfect world.
Maybe Chris could test each one (since they test the pid anyway) and measure the boiler temp vs. the brew group temp and tell us what our particular difference is on each machine ordered?
Sorry for the ramble...Thanks for the tedious work!! I think the PID is a no brainer though.

It doesn't take many ±'s to get to ±2°F variation between machines.

You have the basic accuracy of the PID and boiler thermocouple, TC location in the boiler, the error due to temperature rise of PID, thermocouple and meter accuracy and calibration, position of the TC in the group, ambient temperature, aiflow and connector integrity all contributing.

What is important it is repeatable for any particular machine.

A few things may affect the temperature offset; the location of the thermocouple in the thermowell, ambient temperature, temperature of the water in the pourover reservoir, whether the machine sits near a heating/cooling vent, perhaps even the OPV setting.

The thought also occurred to me that Chris could offer an offset measurement service, but it may not make much sense with those variables. You should be able to quickly hone in on desired setpoints based on taste.

That said, I would like to program the offset into the PID display, just for my own use . I'm certain that can be done, but I haven't broken out the manual.

(BTW, both Dan and I have an Alexia for this review, so they are different machines).

For what it's worth, I have a PID'ed Alexia (different kit than Chris' and professionally installed by third party) and I have found my optimum SV to be around 216 deg F. This value was right in the middle of the range suggested by the installer (210 - 220 deg F). After reading this thread, I have started using warming flushes, but to be honest I didn't find that they made a noticeable taste difference over just pulling from idle. I do not claim to have extremely refined taste sensitivity, but I begin to detect sourness when I drop the SV below 214 deg F and bitterness when I go above 218 deg F.

Thanks very much for all of the work and detailed information presented. It's been a huge help to me.

I know we are only talking ± 2 degrees. I know pulling that perfect shot is not an exact science with so much potential for user error among the steps required.
My real bottom line question is, do I personally, need the PID? I have decided that I definitely do whether it's on my present Silvia or if I order a new ALEXIA with the PID installed.
Thanks for all the hard work and being patient with my inane questions.

Quick Mill Alexia - PID Use, Part 2 - Intershot Performance

Here are 2 graphs showing intershot performance. This procedure was used:

• Warmed machine with portafilter and Scace thermofilter installed for 60 minutes minimum,
• Portafilter removed and pulled a warming flush of ~3 ounces,
• 2 minute recovery and then pulled a "garbage" simulated shot
• Pulled 5 shots with 2 minute recovery between shots, start dump (SD) of thermofilter for each shot,
• 3 minute recovery and pulled a long shot (60 seconds),
• 3 minute recovery and pulled a second long shot

The first graph shows the 5 shots with two minute recovery times, and the second graph adds the longer shots as well.


Click for full size


Click for full size

I think you will agree these show some very good consistency and 2 minutes for recovery is pretty impressive. I did not try a shorter recovery period, my opinion is that 2 minutes is plenty fast for most home baristas.

Data available on request.

jesawdy wrote:Those who are upgrading from Silvia or similar class machine are going to love this part. My "daily driver" machine for the last 14 months or so has been the Rancilio Silvia. Now, don't get me wrong, I think the Silvia is a well built machine. It has often been said that Silvia is a "harsh mistress", and I think she is. My personal experience in the first few days on Alexia is that you can hardly go wrong, comparatively speaking. I've joked before that preinfusion is for wussies, but it sure makes things simpler! I've also used a few other commercial class machines without E61 preinfusion, and they aren't as forgiving as the Alexia.

I have to second this sentiment. Currently I have Alexia & Silvia on demo in my shop - side by side. I probably don't need to tell you that my shots are coming from Alexia. She is more forgiving, quiet, beautiful and consistent... I think I love her!

Many of my walk in customers are wanting the Silvia (for the price point) and I hate trying to 'sell up' because it seems so pushy... But I can't sleep well at night if I don't demonstrate the 2 units side by side - even if most people will not buy up in the end.

I will try to do some side by side pic's

greatinfusions wrote:Many of my walk in customers are wanting the Silvia (for the price point) and I hate trying to 'sell up' because it seems so pushy... But I can't sleep well at night if I don't demonstrate the 2 units side by side - even if most people will not buy up in the end.

I will try to do some side by side pic's

Sebastian, thanks for the comments. I intend to add some side-by-side comparisons of Silvia and Alexia during the next week.

After almost 2 months of being relegated to the basement floor, the Silvia is back in action with Eric's grouphead thermocouple adapter reinstalled (I shamelessly ripped the thermocouple out when I needed one awhile back). She is descaling at the moment and will be ready for a few sessions tomorrow.

I can give Silvia complaint number one.... portafilter lock-in. Locking in the portafilter on the Silvia usually requires reaching for the case to keep it from scooting across the counter. I haven't had to reach for the Alexia once .

Here it is - The ultimate smack down between a "harsh mistress" & a smooth seductress - like 2 Italian she-tigers in a mud wrestling match. Alexia is more beautiful out of the box... Her proportions are very nice and she has a subtle beauty. Silvia is businesslike in appearance... in a good way. Coffee was Josuma Malabar Gold & grinder was MACAP M4.


HBers know all the spec's but I will quickly remind you of the basics:

Rancilio Silvia:
List $600
67 oz. Water Tank
12 oz. drip pan
12 oz. Brass Boiler
Ulka 52 watt vibratory pump
Power: 1100 watts - 120 volts
Size: 13.25"H x 11.25"W x 9.25"D
Weight: 30 pounds
Materials: Steel frame, stainless housing,
Origin: Italy

Quickmill Alexia:
List $895
E-61 commercial group
25 oz. single boiler
Thermosyphon circulation
Ulka 52 watt vibratory pump
Lever Action Semi-Automatic
Water reservoir 3 liters (101 oz)
46 ounce capacity drip tray with
Dual purpose pressure gauge
Low water level safety switch
1400 watt heating element
Weight 38 lbs.
W: 9" D: 179" H: 15 1/4"
Origin: Italy

So first let's look at them side by side:


And profile:


Top view:


Shots were poured using the same volume 14gr. of Malabar Gold in a standard 14gr LM basket with bottomless PF into a 3oz ACF espresso cup:

Rancilio shot:


Alexia shot:


Now for the glass cup profile into a 3 oz. Bormioli Roma cup:

Rancilio:


Alexia:


Tasting Notes:
This was a lot of fun. Both of these girls did well and I believe both can provide a heck of a good shot when paired with good coffee and a bit of practice. The shots were almost indistinguishable in taste. Both produced the aromatic Italian style espresso you want with Malabar Gold. Alexia's shots were more spotted and in fact had an ever so slight edge in taste - just a little more punch.

Joy of use:
This is hands down winner for Alexia. Quieter and more refined in every way with the beautiful E61 group and nicely curved panels. She boasts 4 x the volume in drip tray 2 x the boiler size & about 30% larger reservoir. The lever switch is much more interesting and refined than the rocker on Silvia. The auto shot off for low water is a comfort. Pressure gauge & temp setting (under the hood) are both big pluses...

Final word:
Is Alexia worth the extra $300?
(Not if you are taking that out of your grinder budget)

But - If you have the money and you want a well crafted espresso machine that looks as good as it cooks - I would give it serious consideration.

Hmm, same thing here today.... Silvia versus Alexia.


PID Rancilio Silvia and PID Quick Mill Alexia


Silvia (left), Alexia (right), 14g dose, ~30 sec from pump on for shot time, pulled simultaneously (who needs a 2-group ?)

I'm curious, did you find a need to change the grind setting between the two? I think I will get away with same setting.

Also, when I open the refrigerator door.... I can watch the fridge light pulse with the PID controllers .

jesawdy wrote:I'm curious, did you find a need to change the grind setting between the two? I think I will get away with same setting.

I used the same grind setting. I have tried a step finer on Silvia as well but got overextracted shots.