[Kyle T]

Hi, only discovered this thread today and read through it. Is this really the extent you have to go to with a HX machine? Having just sold my dual boiler I've been considering a HX machine as I've never had one. I figured I had to make sure to give it at least 30mins to heat up, pull a shot and then flush for 4-5 seconds if I wanted to pull another shot. Is this not the case? Could you not get a decent shot with a random flush or is this more about avoiding the flush all together? Also, how much does the size of the boiler affect things on a HX? I've seen machines from 1.1L boilers up to 1.8L. Does this affect much?

 

[HowardSmith]

Hi, only discovered this thread today and read through it. Is this really the extent you have to go to with a HX machine? Having just sold my dual boiler I've been considering a HX machine as I've never had one. I figured I had to make sure to give it at least 30mins to heat up, pull a shot and then flush for 4-5 seconds if I wanted to pull another shot. Is this not the case? Could you not get a decent shot with a random flush or is this more about avoiding the flush all together? Also, how much does the size of the boiler affect things on a HX? I've seen machines from 1.1L boilers up to 1.8L. Does this affect much?

Hi, only discovered this thread today and read through it. Is this really the extent you have to go to with a HX machine?

Well this was the extent that I decided to go to since I was frustrated with not knowing what was going on. You wouldn't need to go to this extent now, just read this thread.

Having just sold my dual boiler I've been considering a HX machine as I've never had one. I figured I had to make sure to give it at least 30mins to heat up, pull a shot and then flush for 4-5 seconds if I wanted to pull another shot. Is this not the case?

That's not a simple question to answer. It will depend on the machine, the group head temp, what temp you want to be brewing at, how long you leave between shots, ambient temp, the boiler temp. All these questions can be answered by using the methods in this thread in conjunction with a group head thermometer.

Could you not get a decent shot with a random flush or is this more about avoiding the flush all together?

Again, not a simple yes no answer because your 'decent' may be different to my interpretation. If you told me you like your espresso brewed with as flat profile as possible and at exactly 93c I could pretty much give you that with my method. With a random flush and no group head thermometer you would be stabbing in the dark. Would that be decent enough for you, I dont know.

Also, how much does the size of the boiler affect things on a HX? I've seen machines from 1.1L boilers up to 1.8L. Does this affect much?

I dont have much experience across a range of machines but thinking from a logical perspective a larger boiler will most likely reduce recovery time between shots, may increase group head temp a little vs a smaller boiler which could mean more group head cooling is required, improve steaming performance for large jugs of milk.

 

[pandabear]

Just came here to say thank you for your efforts, it was a very interesting read and watch!

I share your concerns over the inherent wastefulness of flushing in HX machines so the cooling GH method helping with that whilst giving more accurate and repeatable shot temps seems to be a win/win. I tried it this morning and my Mara (not X) warmed up from off to 88.5c on the thermometer in 20 minutes, shot pulled and temps stabilised slightly above 92c on the thermometer.

Lucky for me that I only have 1/2 shots a day so catching the first one on warm up and then only having to do this possibly once more a day isn't a huge issue!

 

[HowardSmith]

Just came here to say thank you for your efforts, it was a very interesting read and watch!

I share your concerns over the inherent wastefulness of flushing in HX machines so the cooling GH method helping with that whilst giving more accurate and repeatable shot temps seems to be a win/win. I tried it this morning and my Mara (not X) warmed up from off to 88.5c on the thermometer in 20 minutes, shot pulled and temps stabilised slightly above 92c on the thermometer.

Lucky for me that I only have 1/2 shots a day so catching the first one on warm up and then only having to do this possibly once more a day isn't a huge issue!

Good to see your mara responds in a similar way to the appartamento (based on the readings)...

I think this comes down to basic physics really. E61's all weigh about the same, boiler temps are about the same, flow rate is about the same. YMMV but the overall concept is the same for e61 HX machines.

 

[Wasi]

Hello Howard. I also want to thank you for your great work. I also use Fanning for a few days and am thrilled with, how easy and effective it is. I use a Rocket Mozzafiato, with PID and a Rotary Pump. In all previous attempts, I have found, that I do not get a hump at a pressure of 1.2 bar, as is the case in your measurements. For me, the temperature reaches the target temperature relatively quickly and levels off there, with a fluctuation of +/-0.2°. Do you have any idea why that is? Is that rather good or rather bad?

Greetings

Wasi