Breville BES900 Dual Boiler - Owners thread

[samhighley]

Re: Breville BES900 Dual Boiler - Owners thread

Would someone please be kind enough to measure the clearance for me from portafiler to drip tray?

The tallest cup youll get under there (just!) is 11cm.

[artman]

Re: Breville BES900 Dual Boiler - Owners thread

Check out this image as a starting point for dose. More or less depending on the age, origin & degree of roast.

This is using the stock baskets. If using Synesso or VST, then its a whole lot lower!

Cheers, Phil

I thought that the finished level of the tamped coffee should be a smidge below the shower screen (ie 5 cent test), regardless of coffee bean, type of basket etc. This is kept constant (as well as tamp pressure) and the grind is adjusted to get the right flow/volume.

So using a different basket might mean more or less coffee will be in the basket after tamping, but the height/depth of the tamped coffee would need to be the same.

Or am my thinking incorrectly?

Cheers

[nickoyang]

Re: Breville BES900 Dual Boiler - Owners thread

Hi Phil, Barryd and Panoviboy,

I bought a Tiamo generic 58mm blind filter and tested the manufactured OPV seting was 12 bar sharply. The setting just right matched with my observations if the dosing and grinding are corret and appropriate.

I adjusted the OPV to 9 bar tonight and re-adjusted the grind size by fixing the dose amount, then I got the following conclusions on my unit.
1. The gauge reading of my unit actually is very accurate. That is to say, when the OPV is activating, the gauge reading will keep at 9bar constantly.
2. If the PF is under-dose and grinding is too fine, gauge reading will not reach to 9 bar. But if over-dose with the same grind size, the gauge reading stays at 9 bar firmly but it took 45 secs to get 30ml for a single shot.
3. If further adjust the grind size a bit of coarser, gauge reading still stays at 9 bar but it just took 35 secs (including the pre-infusion time) to get 30ml coffee for a single shot.

The final result of pulling shot is very good in flavor and taste, after I adjusted the OPV to 9 bar sharply.

Regards,

Nick OY

[nickoyang]

Re: Breville BES900 Dual Boiler - Owners thread

Hi Phil,

After I adjusted the OPV to 9 bar sharply, I did get very good extractions with correct time and amount. But one thing I noticed is the machine noise gets louder.

I believe the louder sound should be caused by the OPV continuously jittering to maintain a 9 bar pressure.

Will this setting cause long term life cycle issue to the OPV?

Thanks

Nick OY

[shapeshifter]

Re: Breville BES900 Dual Boiler - Owners thread

Nick yes the machine gets louder after adjustment, nothing you can do about it but just live with it.

Very good question that Id be interested to know the answer to as well, Im already looking at replacing the OPV for something more substantial

Ive finally hit the sweet spot between the spong and the machine and am getting absolutely fantastic coffees

[Pavoniboy]

Re: Breville BES900 Dual Boiler - Owners thread

one thing I noticed is the machine noise gets louder.

Yes, this is addressed earlier in the thread. It is normal, and shouldnt pose a problem.
If it does affect longevity of the OPV, I believe it is only a small spring that would need replacing which would be very cheap anyway? Can someone confirm with a bit more than belief?

addit: beaten to it by shapeshifter.

[nickoyang]

Re: Breville BES900 Dual Boiler - Owners thread

Hi Pavoniboy and shapeshifter,

When I adjusted the OPV to 9 bar sharply, I found a perfect coffe puck can almost emulate the perfect blockage of the blind filter but the gauge reading cannot reach to 9 bar sharply (very close but not reach to it). So the principle of physics just fool me around.
I know my grinder is good enough as it has infinite grids with a conical blade inside. So basically, I can adjust the gride size to the optimal point to reach as close as possible 9 bar. If any user using less grids grinder, his BDB OPV can be adjusted a little higher than 9 bar (9.5 bar to 10 bar) so that coarser grinding with a bit of over-dosing can just reach the 9 bar.
Also, I found a long term life time concern on the OPV. The OPV knob is a plastic component and it was turned too much toward to the steam boiler. In the long run, I guess the plastic piece will be aging and cracked due to the repeatedly heat cycling. So I just turned the OPV plastic away from the steam boiler.
When I opened the case of the BDB, the inside placement just gave me an impression of the engine room of a BENZ or BMW. It looks neat and well arranged. I do see Breville put a lots efforts to design the machine excpet for some minor observation I highlighted here and the OPV tunning issue.
As Breville cannot expect every end-user can adjust the unit or has teh luxury to tune every shipped BDB, why cant Breville just do it right at the production line?

Regards,

Nick OY

[citizen_smith]

Re: Breville BES900 Dual Boiler - Owners thread

The tallest cup youll get under there (just!) is 11cm.

Damn, I should of thought of that before I bought them. Thank-you very much for your reply.

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

Are you going nuts having to repeat the same advice again and again?

It feels like it some days..........

Cheers, Phil

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

So using a different basket might mean more or less coffee will be in the basket after tamping, but the height/depth of the tamped coffee would need to be the same.

Or am my thinking incorrectly?

Yes, our stock basket will hold ~18g with the smallest clearance between the screen & the tamped coffee. Throw in a synesso & you get more like21g, using a VST "18g" you get more like 22g. Plenty of places using VST "22g" baskets might have their dose sitting 13-14mm below the top edge of the coffee basket to 18-19g. Rock hard or soggy post extraction pucks seem to be a thing of the past so long as the coffee tastes great.

Cheers, Phil

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

I believe the louder sound should be caused by the OPV continuously jittering to maintain a 9 bar pressure.

Will this setting cause long term life cycle issue to the OPV?

This louder sound is not the OPV opening as it was open before when the 12bar was on your gauge because that pump can actually produce 17bar. The additional noise is from the pump. This is how they sound when their outputs are not fully loaded.

Cheers, Phil

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

Very good question that Id be interested to know the answer to as well, Im already looking at replacing the OPV for something more substantial

14600 "cycles" tells us that the OPV & all the other componentry are very reliable. Why would you want to change your OPV to something that may not be matched very well to the system? Other OPVs may look more "substantial" but at the end of the day, they are only a spring loaded valve & seat that operate in exactly the same way as ours. If you choose one that is not matched to the system then the OPV will perform poorly. I can tell you that spring length, spring rate, OPV outlet diameter & valve/seat shape all have an impact on performance within a system. Again, Im just offering advice from experience.

Cheers, Phil

[>mcknightp]

Re: Breville BES900 Dual Boiler - Owners thread

As Breville cannot expect every end-user can adjust the unit or has the luxury to tune every shipped BDB, why cant Breville just do it right at the production line?

Nick, if youd bothered to read any of this thread or the secific thread dedicated to the OPV, then youd know thats it only affected early AUS & US production & the ongoing production was re-calibrated months ago. Quite apart from that, in any market where the product is sold, you can take it to any service centre & have it adjusted for free. In the US theyll ship you an exchange unit where you cant get to a service centre.

Cheers, Phil

[samhighley]

Re: Breville BES900 Dual Boiler - Owners thread

I can tell you that spring length, spring rate, OPV outlet diameter & valve/seat shape all have an impact on performance within a system.

You mean you didnt just throw a whole lot of components together and hope theyd interoperate effectively?

[TC]

Re: Breville BES900 Dual Boiler - Owners thread

You mean you didnt just throw a whole lot of components together and hope theyd interoperate effectively?

I think that responsibility was allocated to the online eggspurt team ;D