Hi. I am new to the post and I apologize if this is somewhat a redundant question. Please bare with me as I have not been able to find an answer to my question, after spending countless hours of reading forums, reviews etc when trying to decide on a machine.

I am in the market for a prosumer espresso machine, and have settled on a semi automatic machine. Now the big question is whether I go for an Hx or a DB. I do understand the benefits/drawbacks of both machines although I am not quite sure about the water getting stale argument on the DB. Regardless I am leaning towards the Hx machine, but I am unsure whether I can brew at specific temperatures with such machine.
I have noticed that some coffee roasters recommend their coffee be brewed at specific temperatures. I understand that with a DB machine equipped with a PID I can pretty much achieve the temperature I need. What I am unsure about is whether I can do the same with a Hx machine. I have seen Eric S brewhead thermometer. Would I need to adjust pressure stat of a Hx machine to increase or decrease brewing temp and monitor it with such device? Is a PID on a Hx machine useful? I have found a couple of machines that have it however I am not convinced on the benefits. Am i wrong?

If Hx will get me there which machine you'd recommend? I am considering Rocket Giotto Evoluzione or Vibiemme Domobar Super Hx or QuickMill Andreja Premium.

So if DB is the way to go which machine you'd recommend?
I am considering at either Vibiemme Domobar Super DB or Izzo Alex Duetto II.

Any help will be much appreciated! Thanks!

A PID is a glorified electronic thermostat on an e61, DB or HX. There is an offset, which varies with ambient conditions, between the set point and the brew temp. In my office I had to raise the DB boiler temp 3°F for the same group temperature when the summer heat arrived and the aircon is on. Ditto the HX PID at home.

On a pstat controlled HX, the groups will be too hot at idle and you can flush down to whatever temp you like. With Eric's adapter you can nail any temp desired on an HX. With practise, you can nail any temperature without it. Rather than focusing a number, think 'tastes right'. It's all about being able to repeat a routine.

Unless you have identical hardware, take vendor recommendations with a grain of salt. Learn how dose and temp affect a shot. With a new coffee either start at roaster suggestion or your own standard dose, temperature and brew ratio. Regardless of method chosen, you'll probabaly need to adjust for taste.

All of the machines listed are capable of great espresso. Choose the one you'll like to look at for several years.
IMC, Vibiemme. Twice

You can probably find what you're looking for in one of the numerous "HX vs. DB" threads like Expected differences between dual boiler and HX?.

As Ian said, it's fairly simple to control brew temperature with an HX machine by varying your flush routine. Some people prefer HX for this reason, because you can quickly try coffees at different temperatures, rather than having to wait for a PID machine to re-stabilize the temperature of the whole system. The temperature profile of the shot *is* different (look up "HX hump").

mastyl wrote:Please bare with me as I have not been able to find an answer to my question, after spending countless hours of reading forums, reviews etc when trying to decide on a machine.

From Upgrade or not to double boiler:

HB wrote:The HX versus double boiler debate comes up regularly; below is a sample of the more thorough discussions of the topic:

• HX vs DB
• HX vs double boiler in the real world
• The Worst Thing about HX Machines/Heat Exchangers are evil
• Why are HX espresso machines so popular?
• Some thoughts on heat exchanger vs. double boiler espresso machines

For me, the ease with which an espresso machine automatically manages brew temperature isn't a key criteria. The stick shift versus automatic analogy applies, i.e., if I were searching for my ultimate driving experience, I would not limit myself to cars equipped with automatic transmission. However, if I were shopping for my wife, I would eliminate any without it.

If you're convinced that exact brew temperature control is key to exceptional espresso, don't get an HX espresso machine. I personally don't mind the extra steps / intuition they require because I like the flexibility of on-the-fly temperature adjustments and brew temperature profile manipulation (i.e., with practice, you can produce flat or "humped" profiles on demand with certain limits). If that isn't your thing, the simplicity of a dedicated brew boiler with PID control cannot be beat.

mastyl wrote:I have noticed that some coffee roasters recommend their coffee be brewed at specific temperatures. I understand that with a DB machine equipped with a PID I can pretty much achieve the temperature I need. What I am unsure about is whether I can do the same with a Hx machine.

On an HX, you can get exact enough.

Here's a question: should you make espresso at the temperature, dose and time/volume the roaster recommends, or should you make it so it tastes close to the same as at the roaster's lab? If you want the first, you need a DB, if you want the second, a good HX will do; although a top drawer grinder is far more important to the project of duplicating the taste of shots.

I assure you the two are never the same unless you happen to be using the same machine, basket and grinder as the roaster. Why roasters keep making these recommendations beats me.

another_jim wrote:Why roasters keep making these recommendations beats me.

It is useful to a degree and only if roaster actually updated web page to reflect what he is currently roasting. I use those as starting point only. I usually try what is recommended and then adjust to taste. If I come to taste I like quickly this way it saves me some beans. If not, then I search for best parameters on taste alone.

Gentlemen - thanks for the advice.

I would consider the recommended brew temperature provided by the roaster as a starting point. From there I would experiment with increase/decrease of temperature to see how that changes the flavor of the coffee for my palate.

Thanks again.

Both Jim and Dan are spot on. HX will certainly produce temps for exceptional espresso and offer a degree of freedom to work a coffee.

I've used a prosumer HX for a few years and as I've become more capable of tasting espresso I've been able to better brew it using the HX. I'll admit getting the "right" temp isn't overly difficult and as Dan suggests working a coffee at slightly different temps can really produce intriguing results and wonderful coffee.

Thanks Tim - i am convinced that HX can get close enough.

Both technologies are dominant, but since the cost of a good quality HX is pretty much the same as a good quality DB, to me, it makes sense to go with the latter. I will get more precision when brewing and a more energy efficient machine. (ability to turn off one boiler).

mastyl wrote:Both technologies are dominant, but since the cost of a good quality HX is pretty much the same as a good quality DB . . .

Either class of machine will provide you with excellent results, but HX machines are nearly always LESS expensive than a DB of comparable build quality.

That said, go forth and enjoy!