OK, finally got batteries, camera, coffee machine, myself and time altogether in the one place 🙂.
Anger Management wrote:
Remember; Terms / Assumptions / Descriptions often fail to convey the most simple things... 1: Double walled / Pressurised / Fake Crema basket etc etc all have one thing in common... They only have ONE (1) hole to allow the coffee to flow from the basket and into the PF. 1A: A naked PF is a great tool to assist in seeing this. 1B: Or get all your baskets and fill with some water. The standard baskets will just flow. The other type will maybe seep or a few drops until you apply some pressure to the top.
Firstly, my apologies. Yes, it's pretty clear now that my dual wall basket does have a restriction built into it. I don't have a naked PF, and probably won't have one in the foreseeable future. (photos for here, but can't for the life of me, work out how to insert them - see attachments 1 and 2)
Anger Management wrote:
2: The rubber / Si blank with a small pin hole, is often used where there is a reason to bleed any excess pressure. ie. Machines with no OPV. But it also is used in a few other types. 2B: Usually used in the cleaning process and where a tab of cleaning product is used. At the start the tab covers the hole and until dissolved, the system can build to full working pressure and maybe more. Then when the hole is exposed the cleaning fluid can also make sit way through the PF and also clean it. This does not happen when using a true blind.
My silicon disc doesn't appear to be intended to have any hole in it. It acts as a true blind filter. I would expect to see some evidence of a malformed hole on 1 or both sides, but under 10x magnification there is no dimple or mark what-so-ever, on either side. (see attachment 3)
Anger Management wrote:
2C: I tend to always use an old Sunbeam Double wall/floor basket; as I am lazy and thus the PF gets a clean as well. The outcome of this, is that you can check how your machine is working. A: With a true blind, the machine will pump as hard as it can until the OPV starts to work. For a BES 900 that has be set correctly (the OPV can never be calibrated) it should activate at a gauge reading off approx 9.5 to 10 bar ? B: With a pressurised basket the hole acts as a bled and with NO grinds in the basket should give a reading, lower that the blind. The Sunbeam ones tend to give a reading of about 8.5 bar. I am not sure about the Breville ones, as I understand there may be a couple of different types / versions of the Breville dual floor basket. But in general the Breville ones appear to give a lower reading say 7.5 through to 8 bar ?
When I run the clean cycle I have, effectively (and in reality) a true blind filter using the silicon disc, so it doesn't matter which 1cup filter I use, so long as it's a 1cup filter - as per the book). During the cleaning cycle the gauge comes up to 10.5bar and not even 1 drop leaks out of the PF. (Btw, it's timed to run for 370secs on my machine, NOT 360 or 320) I'll continue with a 2nd post so that I can attach a couple more photos
