Breville BES900 Dual Boiler - Owners thread

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

Thanks Phil, im going to try and drop it back in either this arvo or tomorrow morning.

Hi Sam, Ive been advised that the OPV has been adjusted & the machine is ready to be collected.

Cheers, Phil

[nathanrodger]

Re: Breville BES900 Dual Boiler - Owners thread

Impressed with this level of service!

Thanks Phil, im going to try and drop it back in either this arvo or tomorrow morning.

Hi Sam, Ive been advised that the OPV has been adjusted & the machine is ready to be collected.

Cheers, Phil

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

A pretty cool pic of the QC X-ray they do on our steam boilers! Courtesy of Dave Gubbin whos meeting with the factory in China at the moment.........

Cheers, Phil

http://www.flickr.com/photos/6312606...in/photostream

[samhighley]

Re: Breville BES900 Dual Boiler - Owners thread

Hi Sam, Ive been advised that the OPV has been adjusted & the machine is ready to be collected.

Thanks Phil. Odd way to get the news but, hey, its done so im happy!

Looks like he did a great job with it. The repair card read "Tested at 13 bar, adjusted to 9-10 bar".

Ive run half a dozen test shots this morning, and the gauge is pretty much bang on "9". The first shot was with the grinder unmodified which was yielding 30-35 second shots using the 2-cup preset. As anticipated it ran quite a bit longer (about 50 seconds) and was a surprisingly tasty shot, and had considerably improved mouthfeel. Whereas a shot previously felt thin in the mouth, not unlike a mouthful of warm-water, it now has some body and silkiness in the mouth.

I might point out that im a BJCP-certified judge, so im quite familiar with the process of judging beverages.

Interestingly, watching the gauge now while it is extracting around the 9 mark, the needle vibrates rapidly, which I assume is the mechanical OPV cutting in and cutting out? This never happened before. It would rise to, say, 12-13, and just sit there completely steady. This says to me that the OPV wasnt functioning at all before, but I might be wrong. With a 15-bar pump and 13 at the gauge, is it unreasonable to assume that 2 bar was being "lost" in the system, rather than that the OPV was limiting to 13 bar?

[samhighley]

Re: Breville BES900 Dual Boiler - Owners thread

A pretty cool pic of the QC X-ray they do on our steam boilers!

That is cool. Checking for cracks?

[cdhjrf]

Re: Breville BES900 Dual Boiler - Owners thread

Interestingly, watching the gauge now while it is extracting around the 9 mark, the needle vibrates rapidly, which I assume is the mechanical OPV cutting in and cutting out?

Yep mine does the same..

[TC]

Re: Breville BES900 Dual Boiler - Owners thread

Perhaps its because so many DB owners want to see a reading of 9 bar on the gauge when the opv opens. :-?

My experience with other machines is that a gauge reading of more like 10.0-10.5 (ish) bar allows for a 9 bar extraction.

Ill be shooting for that ballpark when I adjust mine on Saturday morning and if its actually a tad high, no problemo

I agree with Phil that extraction pressure (give or take) is far from the most significant of variables.

Chris

[cuppacoffee]

Re: Breville BES900 Dual Boiler - Owners thread

Interestingly, watching the gauge now while it is extracting around the 9 mark, the needle vibrates rapidly, which I assume is the mechanical OPV cutting in and cutting out?

Yep mine does the same..

Gauge flutter is usually an indication that you are choking the machine.

Either grind coarser, dose less, or use a combination of both, still aiming for a runny honey pour.

[samhighley]

Re: Breville BES900 Dual Boiler - Owners thread

Gauge flutter is usually an indication that you are choking the machine.

What I see now is pretty much exactly what this video shows.

[cuppacoffee]

Re: Breville BES900 Dual Boiler - Owners thread

Gauge flutter is usually an indication that you are choking the machine.

What I see now is pretty much exactly what this video shows.

Watch closely and you will notice that the flutter is dying out as the coffee extraction commences. Unfortunately the video pans away from the gauge at that moment.

What I said is correct.

[howser999]

Re: Breville BES900 Dual Boiler - Owners thread

What I said is correct.

But if he was choking the machine, wouldnt the OPV kick in and the needle stay stable? I know that when I choke the machine I dont get flutter...

[TC]

Re: Breville BES900 Dual Boiler - Owners thread

What I said is correct.

But if he was choking the machine, wouldnt the OPV kick in and the needle stay stable? I know that when I choke the machine I dont get flutter...

The OPV is in line with the pump- which is a vibration pump. At the point of release, I would have thought that any operation of the OPV would (should) mirror the frequency of the pump.

In many HX machines, its remote and connected via a good length of silicon hose which can iron out some of the fluctuation. I guess gauge design and the actual location within the system of the gauge capillary tube is possibly significant as well.

Might just be me, but I rarely (if ever) look at a gauge during extraction. Im way more interested in the shot. If it wants to vibrate, good luck to it!

[howser999]

Re: Breville BES900 Dual Boiler - Owners thread

The OPV is in line with the pump- which is a vibration pump. At the point of release, I would have thought that any operation of the OPV would (should) mirror the frequency of the pump.

WOuldnt that mean that during normal opertaion you would also see fluctuations? Unless your are suggesting that at the cut in pressure of the OPV the vibratory nature of the pump cause fluctuations. But that would have to be right at that point, and would have to stay there during the brew rather than smooth out (like you are suggesting, but unlike what toasty is experiencing). Perhaps toasty can upload another vid?

[Dennis]

Re: Breville BES900 Dual Boiler - Owners thread

First, not all opvs are the same. In the case of the Breville if you use a blind filter the gauge will not flutter because there is a steady stream of water escaping from the valve. It flutters if the flow isnt steady. More likely at some point during vibe pump operation or when the resistance at the other end ie. Coffee grinds, are not quite perfect. Perhaps ironic but if coffee grinds are way off you probably wont see any flutter at all. The gauge would be likely to behave differently with a centrifugal pump but thats another story.

All this may be of interest and help in understanding function, but wont make a better coffee.

CW: Really, I cant thank you enough for expressing your views about what you consider to be my lack of humility and customer service. I disagree with your perspective.

[jamierk]

Re: Breville BES900 Dual Boiler - Owners thread

Just a short note to say that a month in and still loving the DB. Even more its great to see some useful discussion from knowledgeable people on this forum. I cant think of many other domestic purchases ive made where i can get feedback so easily from the company representatives.

Two things ive noticed so far. Using the smart grinder combo with the DB, set to 2 shots with an extra notch of ammount i underdose (based on the 5c test) and with 2 extra notches i overdose (get a shower imprint without extracting) (if ive incorrectly diagnosed the dosing, please let me know). Seems the best result is running 1 shot at 1notch and a second shot at 2 notches (from the grinder). this weighs in to be approx 19g (cheap digital scales, really wish i had some with an extra degree of precision).

Second thing is, i really need to be careful with how far i lock in the group handle. When viewed from above, with 12oclock being straight into the machine, i need to turn it to at least 5 oclock (ie just pas the little arrow indicating locked, definitely past the 6 lock point). If i dont i have seen the group handle loosen itself and come out during extraction. I think i had seen someone else with a similar result. Should I be concerned? I dont wish to wear the group seal out prematurely.

Small issues I think, given how good the coffee i get out from the machine with little effort. Also, since i came from the Em6900 sunbeam, my milk texture is 1000x better. Nice to know it was not so much me ans the machine holding me back previously.

Thanks guys, some really great information in this thread.

Jamie