Live chat wasn't the best experience to be honest. It felt like I was talking to someone working off a flow-chart of how to troubleshoot brewing problems rather than to someone who knows their coffee from first-hand experience and can draw on that to help someone.
I opened by explaining the problem I was having - the roast was too dark, and so brews were bitter. I was unable to hit any sweet notes, which gave something drinkable as espresso, but as americano or milk-based all you could taste was the charcoal flavours of the roast not the coffee.
At this point, I was asked how I'm brewing my coffee. I had already said it was as espresso, so I checked the person I was talking to had read my opening post. They assured me they had, but needed to check if I was using a machine to brew. (How else would anyone make an espresso?!).
So I told them the exact make and model of my machine - espresso machine, grinder and even the PF basket I was using. I gave my recipe - grams in, ml out and time. They told me that bitter notes are usually because of over-extraction so suggested I grind more coarsely. They also gave me a link to your espresso brewing guide, which was a tad patronising and surely unnecessary given they could already work out I was someone who had got past the level of advice in the guide. By the time you have fitted a PID controller and know the brand of basket you're using, you probably don't need pointing to a beginner's guide to espresso.
Being more coarse could have fixed things potentially, but I have no trouble dialling in other beans, and if I was more coarse I'd have a gushing brew. So I suggested that maybe this would mean the brew going through too quickly.
At this point, they wanted to check with someone else. Before going, they wanted to check the exact model of machine I was using. I'd already told them it was a Sylvia. If I'd told them it was a Rancilio, they could have asked what model of Rancilio. But to ask me what model of Sylva (sic), only suggests they haven't met one. In case it was relevant and they were in fact super expert and wanting to be really precise, I told them it was a Version 3.
The feedback from whoever they asked was now that I needed to grind more finely (the opposite from what I was first told). That, too, may help. But at no point did they think to say what I suspected all along: "It sounds like these are darker beans than your taste prefers, may I suggest next time you buy X, Y or Z - they're more lightly roasted."