Confirmed that it was the beans.
I've now had about 10 days or more away from the Aldi Dark beans - just made one now, and it's definitely the beans. Bloody taste of tea in there!
Your thoughts on grinding?
When it comes to grinding, I have the Aldi $100 automatic jobbie which does a great job. Set it to the finest setting, push the button and away it goes - won't start if the catcher isn't in place. Quantity is also selectable. The down side is that it's very messy, and using plastic elements in the construction makes the static charged coffee spread around the bench, and elsewhere. (and it's a very dry climate up here - tool steel hanging on the wall in the shed doesn't rust...so that contributes to the static charge).
I make 2-3 Moka pots per day, and each yields a mug for two people, plus a very small follow up. There is no way I'm going to grind up for each brew - it's in a different room, it's a messy operation. I'm not into the ritual of it.
I may be regarded as a philistine for this but.....
So I usually grind up about ½kg at a time which lasts about 7-8 days. I have a professional standard Orved 12 vacuum sealer so I can properly vac-pack the remaining beans. I pack down the ground coffee with a tamper to get the air out of it as much as possible, and keep it in a jar in the kitchen.
I can't say that I've done a head to head taste test of ground-one-week-earlier verses freshly ground, but every time I do a grind I do have a brew, and I'm blessed if I notice any difference in the flavour.
There's no "Oh, that tastes better" moment. As I said earlier, some of the best coffee I've had has been from these week old grinds, and reheated after being brewed 2-4 hours earlier, possibly overnight.
Can anyone say with conviction that they notice a difference? If so, how much? Or is it more of a part of the ritual?
Follow up on the Dark: So I ditched that last "tea" brew and made a fresh pot of Lavazza - which I regard as ordinary, only just passable - ....and it too now tastes of tea, so I think it may take a while to flush the crap flavour out of the pot somehow. If this is the case, and it sure seems like it, then this is what was throwing me off a couple of weeks ago when every blend I ground and brewed seemed to taste of tea. This was why I left the Dark alone for a good long while, so that the crap flavour would be well flushed out - and I noticed that the flavour got better. Time to do a couple of coffee-less boils to flush it out.
How are your coffee beans lately? Mine are GREAT again!
So boiling in very weak vinegar and then Bicarb is done (about 2 tsp Bicarb to 10 litres). The vinegar didn't dislodge anything but the pot was nice and shiny after it. OTOH, the bicarb follow-up did dislodge some stuff - not a huge amount but certainly visible.
Just bought a fresh packet of Campos to get us through until the Silicia arrives, and I'm finally having the standard of coffee I have come to expect from this set up! It would seem that when crap beans are put through this Moka pot they leave a residual crap flavour which then takes a number of subsequent brews to get rid of.
Perhaps I need to boil the pot in Bicarb maybe once per month to freshen it up.