Ok. I've had my gaggia espresso / MDF setup for around ten months now and have given some serious thought to installing a PID in an effort to improve my shots. I should note that all I drink is espresso; steaming performance is an absolute non-issue, so any incidental impact that the PID might have on it is of no account. I have enough electronics background that installing a PID/SSR setup as per the commonly-available instructions is not likely to be difficult... but the question is, am I likely to see a worthwhile improvement in the product?

If I do PID my Gaggia, I'll be using parts from Auber Instruments (as they fit my budget; much as I might want to use a watlow or a fuji, the price is simply too high).

So, any comments / suggestions / warnings?

Thanks

beanmuncher wrote:...but the question is, am I likely to see a worthwhile improvement in the product?

I assume the results from PID'ing a Silvia are much the same: It eliminates the tedium of temperature surfing and avoids temperature-related mishaps, but the "absolute performance potential" is unchanged. That is, the best shot of a PID'd Silvia is no better than the stock Silvia; the typical shot may be improved due to the reduction in operator errors.

As I understand it, PIDing a machine simply reduces variance in non-operator parameters for the shot - if I can get an accurate temperature, then almost all of the potential for failure is on my side of the portafilter handle.

beanmuncher wrote:...if I can get an accurate temperature, then almost all of the potential for failure is on my side of the portafilter handle.

Well, kind of. Different espresso machines have different "forgiveness factors." For example, the E61 group is frequently praised for its tolerance of minor errors in barista techniques. While temperature management is often cited as the number #1 reason for upgrading, improving the overall likelihood of a good extraction is a close second (the Buyer's Guides attempt to quantify this quality in the morning after score, and to a lesser degree, the exceptional espresso score).

Pardon my rambling, it's getting late.

If you would kindly fill in your profile, you might be surprised to learn that someone in Your Town, Your State has already PID'ed a Gaggia and could offer first hand experience.

Certainly everything Dan says is correct; the PID will dramatically stabilize temperatures throughout the machine and this can be best demonstrated by simply INITIALLY hooking the PID up as a temperature meter and noting the swing in boiler surface temps while operating off of the stock thermostat. Do a "system" calibration in an ice slurpy for 32F and double check with boiling water corrected for your altitude and barometric pressure.

Auber Instruments is a good company to do business with - he is a fast, reliable shipper. I would, however, recommend you source the thermocouple from Omega (Washer style, No. 6 screw, Type T, SLE wire, PFA insulation). Just mount the thermocouple under the stock brew thermostat and be careful when tightening the thermostat down.

If you do a search on this site, on CoffeeGeek.com, and on alt.coffee (http://groups-beta.google.com/group/alt.coffee/topics) for Gaggia PID, you might have to do some sifting, but there is a lot of info out there.

Eric S.

If you decide to do this, hope you will keep us posted on the process, progress and results. Will look forward to hearing about it.

I PIDed my classic a year ago and do not regret it.
The main advantage would be the increased shot to shot stability. It is also much easier to fine tune the temperature.
Another problem with the classic is the small boiler. The temperature during the shot decreases about 6-8 C.
This can however be taken care of by preheating the water before the boiler, but thats another story...

Swemarv wrote:I PIDed my classic a year ago and do not regret it.
The main advantage would be the increased shot to shot stability. It is also much easier to fine tune the temperature.
Another problem with the classic is the small boiler. The temperature during the shot decreases about 6-8 C.
This can however be taken care of by preheating the water before the boiler, but thats another story...

Or by temp surfing during the extraction with the steam switch.

It's a PITA, but ya gotta do what ya gotta do to get the most from what you've got.

At this point, I'll probably go for it - considering that I work as a lab researcher, I have a little obsession with data. I'll probably put in the order today and will hopefully have the parts in by next week (which would be nice as I'm on break through the 14th).

So, one basic Auber Instruments PID, 1 SSR and thermocouple... done. Ordered 'em.

Swemarv wrote:Another problem with the classic is the small boiler. The temperature during the shot decreases about 6-8 C.
This can however be taken care of by preheating the water before the boiler, but thats another story...

I, for one, would be interested in hearing this story. I have an unmodified Gaggia Coffee, and temperature surfing (after grinder tuning) is my next area of interest.

Do tell!
t++