Heat-up time E61 double boiler vs HX

#1: Post by **DeGaulle** » February 10th, 2019, 4:24 pm

E61 heat exchanger machines usually have a TS restrictor for the grouphead not to idle too hot. On a DB machine where water circulates between the brew boiler and the group, such restrictors shouldn't be necessary; in fact, not having a TS restrictor I expect should benefit recovery time. My questions are these:

1) Is it actually the case that TS restrictors are typically omitted from DB machines with an E61 group?
2) How does the heat-up time of an E61-based DB machine typically compare to that of an E61-based HX machine? I learned that the brew boiler of the Lelit Bianca is initially fired up to 266 deg F and then left to cool down to where the PID set point is, but the GH will heat up faster because of this. Is this unique to the Bianca or do other E61 DB machines have similar features?

I know a timer takes away the whole "long heat-up time" issue. However I would like to be able to switch the machine on when an unexpected visitor arrives and be able to brew not too long after that or switch the machine off for a few hours as I e.g. go to the gym and upon returning not to have to wait too long for it to heat up again.

I am considering an upgrade from my BZ10 later (but not in any particular hurry) with an E61-based (HX or DB) machine being one of the options. However the BZ10's short heat-up time is a practicality I really like and would like not to lose too much on when selecting another machine.

#2: Post by **another_jim** » February 10th, 2019, 6:11 pm

I'm not sure an E61 HX is an upgrade from the BZ10; more a sideways step. You add preinfusion, but you subtract the much better water dispersion system. A DB will steam better, and allow you to pull much longer shots without overheating. The Brasilia group the Bezzera uses in its BZs does best with lower doses and finer grinds. If you are looking to do higher dosed shots, the E61 will do better; but at lower doses, I always thoought he Brasilai group produced cleaner shots.

The heat up times of a DB or HX E61 are probably not systematically different, around 30 minutes if the controls are meechanical. The Lelit's PID/computer overheats the brew boiler at startup to get a faster warmup of the group; and this can certainly be done with any DB or HX system providing it uses a PID rather than mechanical controls. But even with this tweak; it takes 20 minutes before the group is ready to pull a shot. I remember the BZ10 being ready in about 8 to 10 minutes.

None of this takes flow/pressure profiling into account. The lowest cost flow/pressure profilers are based on E61 DBs, but this is more an accident of the marketplace than anything inherent to the designs. Adding a needle valve to the BZ10 might work just as well.

#3: Post by **lagoon** » February 10th, 2019, 6:18 pm

If there are times when you are only pulling shots and don't need steam, then a DB can be quicker than a HX.

Some double boilers (eg: Pro700/Synchronika among others) allow you switch off the steam boiler, something you cannot do in a HX for obvious reasons.

When you do this, the machine gives 100% priority to the brew boiler element, and gets the brew water up to 94C or so in a few minutes.

Of course you do need the heat to propagate through the metal of the grouphead, however this can be sped up with a few flushes. Using this approach you can have the DB ready to pull shots in around 20 minutes.

#4: Post by **Snoroqc** » February 10th, 2019, 10:06 pm

lagoon wrote:Some double boilers (eg: Pro700/Synchronika among others) allow you switch off the steam boiler, something you cannot do in a HX for obvious reasons.

When you do this, the machine gives 100% priority to the brew boiler element, and gets the brew water up to 94C or so in a few minutes.

pro 700 heat the brew boiler first. Don't need to switch off the steam boiler. I have a smart plug, I programmed it. And I can start the machine away from home.

February 11th, 2019, 3:15 am

Thanks for the responses so far gents. I mentioned the E61 since I am curious to what the preinfusion feature wll bring to the table in comparison to the BZ group and if it might do better with lighter roasts. Jim, I second your comment that the BZ performs best with lower doses, although I do get good results with a 17 grams Strada basket with quite a few coffees too. I am not considering upgrading for the sake of updosing.
Heating up the BZ grouphead still takes 20 minutes (minus 5 minutes if I run a heating flush as soon as the boiler is up to pressure) and since I added a Cafelat XT portafilter I typically let it sit even a bit longer since it is heavier and I think the stainless steel takes longer to heat up by heat transfer from the brass group.

#6: Post by **BaristaBob** » February 11th, 2019, 7:22 am

Not to disrupt the discussion on E61 heat up time, but just as a reference point for a saturated grouphead design like mine (Breville Dual Boiler), my heat up time is 8 minutes from 68F to 200F. This is extremely important to me just as the OP said, when unexpected guests show up, or for me, when the wifey says it's tea/coffee time (she won't drink coffee...everyone in the whole neighborhood loves my coffee...but wifey has caffeine problems, so it's tea for her), she won't wait 20 minutes but 8-10 minutes works so we can sit down together.

As I said...just a reference point vs. E61.

#7: Post by **JonF** » February 11th, 2019, 11:44 am

While it's kind of an old design, the dual-boiler LaSpaziale Vivaldi offerings a few user-friendly features. They make it especially easy to shut off the steam boiler, with a prominent dedicated button. I know that many machines offer this ability, but on some you have to dig thru menus, on at least one you have to move the drip tray to find the switch.

They also offer an optional integrated on/off timer. For example, I have both boilers come on before breakfast, then shut off the steam boiler for the rest of the day. If I do want steam, since the brew boiler is already hot it's about 10 minutes or so to build steam pressure. The plumbed version also offers optional line-level preinfusion.

February 11th, 2019, 11:56 am

BaristaBob wrote:Not to disrupt the discussion on E61 heat up time, but just as a reference point for a saturated grouphead design like mine (Breville Dual Boiler), my heat up time is 8 minutes from 68F to 200F. This is extremely important to me just as the OP said, when unexpected guests show up, or for me, when the wifey says it's tea/coffee time (she won't drink coffee...everyone in the whole neighborhood loves my coffee...but wifey has caffeine problems, so it's tea for her), she won't wait 20 minutes but 8-10 minutes works so we can sit down together.

As I said...just a reference point vs. E61.

Duely noted AND appreciated.

The BDB is marketed in Europe under the Swiss brand of Solis by the name Solis Triple Heat. It was introduced here only little over a year ago as I recall. In terms of features for the price I reckon it can't be beaten, but I have a soft spot for the more traditional Italian designs.

February 11th, 2019, 12:05 pm

And I understand..as I keep one eye on the Lelit Bianca thread.

#10: Post by **Peter_SVK** » February 11th, 2019, 5:36 pm

DeGaulle wrote: ... The BDB is marketed in Europe under the Swiss brand of Solis by the name Solis Triple Heat...

As far as I know also as Catler ES 9010 Dual Boiler, however no longer available for sale yet.