PID HX Boiler Espresso Machines: Bezzera BZ07, Profitec Pro 500 PID and Rocket Evoluzione R Giotto

by Marc Buckman February 21, 2018

 

Today, a technical comparison of three PID equipped espresso machines with heat exchange boilers. We put them through their paces and have detailed test results including scace brew temperatures, group heat up times and steaming performance.

Hey espresso lovers Marc here from Whole Latte Love. Machines with heat exchange boilers allow you to brew and steam at the same time and PID control gives you very accurate brew temps. Now PID is pretty much standard on dual boiler machines but until recently there were not many heat exchange boiler machines with PID.

The machines we’ll look at today: The Bezzera BZ07. It’s a PID machine that’s been around for a few years. It’s the slimmest of the three so good choice if you’re short on space. It features volumetric dosing for programmable brewing and an electrically heated group head for quick heat-up and added temperature stability. The Profitec Pro 500 has been around for awhile as well, but the PID version is relatively new—it rolled out in the fall of 2017. The non-PID 500 has been a top seller. Excellent design, quality components and construction put this E61 group vibration pump machine in the sweet spot of performance and value. The Rocket Espresso Evoluzione R uses an E61 group as well but upgrades to a rotary pump and is the only plumbable machine of the group. We’ll be looking at the Giotto version of the Evo R with its distinctive angular side panels.

Here’s a chart with the basics. A big difference in width with the BZ07! It’s two inches narrower than the Pro 500 and nearly 3.5 inches skinnier than the Rocket. The BZ07 has an electrically heated group while the others use an E61 group heated via a thermosiphon from the boiler. The Bezzera and Rocket have vibration pumps while the Rocket uses a commercial rotary pump and is the only machine which can connect directly to household plumbing. For boilers, it’s a 1.5 liter copper in the Bezzera, 2 liter stainless steel in the Profitec and 1.8 liter copper in the Rocket. And, all machines have PID temperature control.

So let’s get right to some test results. I first took a look at heat up times—that is how long from power on until the machine was fully warmed up and ready to brew. All three machines reached their set temperature as indicated by the PID at 7 to 8.5 minutes after power on. But they are still not ready to brew. To determine when they were ready to brew I wanted to know when the brew group was fully heated to a stable temperature. So I attached a digital thermometer to the top of the group on each machine and recorded the temperature once a minute for 45 minutes. Here’s a graph of those results. I was looking for 3 consecutive minutes with less than 3 degrees variation and temperatures that were no longer climbing.

The Bezzera BZ07 was the clear winner. The group was stable after just 18 minutes. For the Pro 500 it took 38 minutes and the Rocket got there after 41 minutes. A couple of things to note: for the BZ07 you can see the wobble in the graph line as the thermostat for the electrically heated group cycles on and off once it reaches temperature. The wobble ranged from 168 to 173 degrees. Also keep in mind there are ways to shorten heat up time on all the machines. You can run blank shots to help heat the group up faster. Or you could use a timer to have the machines turn on and heat up before you’re ready to use.

Next up are scace device brew temperature readings. For these I let the machines fully heat up with PID’s set to deliver brew water at 200 degrees. I then recorded the temperature registered by the scace 2 ounces into a simulated extraction and repeated the test five times on each machine at 2 minute intervals. As you can see the machines were very consistent always within about a degree and a half of the 200 degree desired temperature. In Heat exchange machines the boiler runs far hotter than the brew temperature you get at the group. The Bezzera uses an offset to correct that so you set the PID to your desired brew temperature.

It’s a little different on the Profitec and Rocket machines. For these, you use a chart in the manual and get an actual boiler temperature that produces a desired brew temperature. Using the charts and adjusting a bit thru trial and error with the scace I used PID settings of 254 for the Profitec and, 246 on the Rocket.

The next test was for steaming power. For this I timed how long it took to heat 6 ounces of water from the 64 degrees out of my tap to 140 degrees on a frothing thermometer in a steaming pitcher. I repeated this test five times on each machine and averaged the results. It was 23 seconds for the Bezzera, 26 seconds on the Profitec and 24 seconds on the Rocket. Those are all pretty close. So no huge difference. One thing I did notice, in extended steaming, power falls off a little on the Bezzera and Rocket while it remains consistent on the Profitec. But you’d have to steam large amounts of milk to notice that steam power tailing off.

So in this group of machines brew temperature stability and steaming power are very similar. The big differences come down to size, heat-up times, group type, pump type and whether the machine is plumbable. Some other differences The Bezzera has programmable volumetric dosing, uses lever valves, and steam and hot water dispense on the same side of the group. A dual gauge reads both boiler and brew pressure. And, unlike the other two machines which hide the PID display behind the drip tray it’s visible on the BZ07. The Profitec has large easy to operate low-wear sprung valves. And, in my opinion it’s the best engineered of the bunch. Long term, it’s probably the most reliable. The Rocket is unsurprisingly the most expensive of the bunch currently priced 25 to 30 percent more than the others. But it is plumbable and has the desirable rotary pump.

So which is right for you? Well if your in a situation where counter space is valuable there’s not many options better in a heat exchange machine with PID than the Bezzera. If solid build, long-term reliability and value are your thing go with the Profitec. If you want a plumbable heat exchange machine with rotary pump and that Rocket flair the Evoluzione R Giotto is the machine for you.

All of these machines and more are available now from Whole Latte Love. If you have any questions on these machines or anything coffee use those comments and I’ll get you the answers.

I’m Marc, thanks for reading and I hope you’ll subscribe and come back soon for more of the best on everything coffee brought to you by Whole Latte Love.

Marc Buckman
Marc Buckman

Marc is Whole Latte Love's resident videographer and expert on everything coffee. He built our YouTube channel from the ground up in 2009, demystifying the world of coffee for upwards of 100k subscribers by producing over 1000 in-depth videos. Marc enjoys hiking, scuba diving, and saving the lives of his coworkers when the kitchen runs out of coffee by sharing some of his own.