Bezzera BZ10 flushing, underdosing, etc.

Need help with equipment usage or want to share your latest discovery?
lhkt
Posts: 48
Joined: 7 years ago

#1: Post by lhkt »

Hi all,

Finally brought my machine over from Singapore and a couple of observations, pros and cons. First thing I did was to take it apart and adjust the OPV to around 9.5 bar from factory 12

PROS:
  • Like the warm-up time - 25 minutes does the trick. This is quite useful in the mornings
  • Steam pressure is pretty sweet - at weekends when we make espresso as well as milk based drinks with wife this is a blessing.
  • Aesthetically, the BZ10 is a nice machine and a pretty addition to any counter-top.
CONS:
  • Pretty much the only thing I don't like is the low shower screen and the need to under-dose. Currently using a VST 20g basket and I dose around 18g. However, with this dosage the ground coffee is under the rim level and can't distribute with my fingers. I'll have to get one of those OCD style distributors eventually. Also, there is almost always some coffee stuck to the shower screen, which I don't like. How do you guys under-dose on your BZ proprietary grouphead machine?
2 QUESTIONS:
  • Water-wise I use reverse osmosis (RO) water and add Third Wave Water mix to it. Water is not hard here so based on that what's your recommendation on descaling? Once a year? Any extra packets I could use to keep water PH at bay? Saw one of those from Rocket which you need to soak and drop in the water reservoir. Any good?
  • Last but not least another water/flushing related question. I usually have an espresso in the morning around 7 and another one at 4pm (and perhaps some V60 in between at my buddy's shop) so what I do is fire up the Bezzi, after around 20-25 mins I do a short flush followed by grinding, tamp, etc. and pull the shot, shower screen cleaning short flush and quick backflush. Hardly leave the machine on for long period of time which would require a more extensive flushing/boiler recovery. What's your water friendly flushing routine for your dragon type HX machine?
Thanks,
Laci.

User avatar
hankbates
Posts: 446
Joined: 13 years ago

#2: Post by hankbates »

I might be rather easily satisfied, but I have yet to flush (other than for cleaning) at all on the Livia 90 (same dragon(?) group head design) which I have been using for about a year. Prior to that I had about 20 years experience on a LP Pro, now enjoying a well earned rest.

I only make 2 lattes each for my wife and me every morning. The first pair of lattes are drawn as soon as the pressurestat (~1.2 bar) shuts off, and the second pair somewhere in the warmup period, timing based on how hot the group head feels, usually soon after the anti-vacuum valve stops hissing. (the second set of lattes usually is made 30 minutes or so after the first)

I've been using distilled water plus a pinch of K2CO3 (rpavlis recipe) for years, in both the Pavoni and the Pasquini. I have never seen any need to descale at all; the LP boiler looked like new whenever I looked inside, and the L90 also showed no scale the one time I opened it.
Some people rescue dogs and cats, I like to rescue Livias…

DeGaulle
Posts: 545
Joined: 10 years ago

#3: Post by DeGaulle »

Prior to the first shot I flush past the end of water dance (look for a continuous even liquid flow), which usually takes about 6 seconds. Lately I also started verifying that the flush is sufficient to start a heating cycle. Then I do my dosing, WDT and tamp. By the time I am ready to pull, the heating cycle has finished. This is similar to how one would temp-surf a single boiler machine, but also on this machine it is a point of reference that gets me consistency and usually good results with medium roasts.
In my opininon BTW, this is not as strictly a "dragon" as Dan (HB) has defined it in the Newbie Introduction video series. The lesser mass of the grouphead compared to an E61 will make for a shorter thermal memory, but even say 10 minutes after the first shot it doesn't flash-boil quite as much as it does the first time around. A quick flush-scrub-flush of the screen prior to prepping my second shot is often sufficient.

Regarding your dosing question, I use a 17 g Strada basket and dose just that (16.5 - 17 grams). I dose into a spouted container, weigh it and then use a funnel to pour the grounds into the PF. While flushing the GH I stir the grounds. That also brings the level of grounds well below the rim. Tap the PF on the counter once or twice and the grounds will usually settle nicely and even. Tamp, lock and load.

I use ion exchange softeners for my tap water, which has about 120 mg/l of hardness and 110 mg/l of alkalinity (both as CacO3 equivalent) that I use 2-3 months. Then for a month I switch to a Brita filter jug that tends to slightly reduce pH and reverse any initial hints of scale. That keeps me from having to worry about scale for 2-3 years until I have it serviced.
Bert

lhkt (original poster)
Posts: 48
Joined: 7 years ago

#4: Post by lhkt (original poster) »

Thanks for the contributions guys!

Today I tried dosing full 20g into the VST and to my surprise there wasn't more residue on the shower screen than before (with 18g) - weird
Used my home roasted Colombian Huila and it was a great shot. Yirgacheffe Aricha is still resting :)

Will see about the water, RO+Third Wave should be okay, but may switch to home made water later on.

One more con may be the short drip tray. Could be 1-2 cm longer.

bas
Posts: 374
Joined: 15 years ago

#5: Post by bas »

In my experience these machines perform better without flush. only a 2 second screen flush.

The HX volume is low and by flushing too long one heats up the grouphead resulting in hotter shots.

I tested it with a simple thermocouple in the basket. So not in a very sophisticated way but anyway.

I was really surprised because everyone talks about cooling flushes. I think the reason for the water dance is the much bigger volume that faster hits the grouphead with open flushing. With coffee the flow is much slower and the grouphead can sink the heat sufficiently.

Just try!

D12edpresso
Posts: 17
Joined: 8 years ago

#6: Post by D12edpresso »

Hi good to see another owner of bz10
I bought the machine in 2016

On the dose, I also think the machine prefer under dose, I usually put 14g on 15g VST and 20g on 22g IMS basket.

I also did lower the opv from 12 to 10 and just yesterday lower it again to 9 haha

On flushing, I also usually do a cooling flush similarly like you I think

On my experience, I think this machine produce a brighter espresso / cappuccino, compare to cafe machine, how's your experience so far?

User avatar
slipchuck
Posts: 1485
Joined: 7 years ago

#7: Post by slipchuck replying to D12edpresso »

Does the 22g basket fit in a two spout portafilter or does it need to be bottomless?

Randy
“There is nobody you can’t learn to like once you’ve heard their story.”

D12edpresso
Posts: 17
Joined: 8 years ago

#8: Post by D12edpresso replying to slipchuck »

Yes it fit with the standard bezzera basket

lhkt (original poster)
Posts: 48
Joined: 7 years ago

#9: Post by lhkt (original poster) »

bas wrote:In my experience these machines perform better without flush. only a 2 second screen flush.

The HX volume is low and by flushing too long one heats up the grouphead resulting in hotter shots.

I tested it with a simple thermocouple in the basket. So not in a very sophisticated way but anyway.

I was really surprised because everyone talks about cooling flushes. I think the reason for the water dance is the much bigger volume that faster hits the grouphead with open flushing. With coffee the flow is much slower and the grouphead can sink the heat sufficiently.

Just try!
May try, especially if the water dances right after a flush too. The reason why I do flush if to empty water from the pass through tube.
Right now, I let the water flash boil until an even flow, then lock in the prepared portafilter, wait till the boiler recovers (first overshoots, then settles down - it can all be seen on the manometer) and then pull the shot. Pretty consistent so far. If you want a bit higher temp, then pull immediately after the pressure peaks.

lhkt (original poster)
Posts: 48
Joined: 7 years ago

#10: Post by lhkt (original poster) »

hankbates wrote:
I've been using distilled water plus a pinch of K2CO3 (rpavlis recipe) for years, in both the Pavoni and the Pasquini. I have never seen any need to descale at all; the LP boiler looked like new whenever I looked inside, and the L90 also showed no scale the one time I opened it.
Hank - do you have link to this water recipe? The closest I found was Matt Perger's recipe:
Matt Perger's water recipe for coffee - Is it ok/safe for espresso machines? What do you think?

Thanks,
Laci.

Post Reply