those two properties do not even touch on the quality of the beans, nor how those flavors are developed and maintained through roasting. measuring the darkness of roast does not tell you how dark the coffee should have been roasted for optimum flavor profile.
I'm not aware that it can be done analytically, it requires trained tastebuds, and in my experience, tastebuds trained on many coffees over time (a sort of 10,000 hours type idea, probably needs neuroplasticity); most roasters have a sort of narrow "tunnel vision" based around their own coffees which they taste relentlessly.
to actually taste delicious coffee it needs to cool down quite a bit, below 130F 55C which is not very hot. I understand the pleasure of a hot cup of coffee, but that pleasure is not flavor pleasure.
Where do you draw the limit personally ?
There's some legitimate room to spend much more money when making Espresso. But a lot of the more expensive options would be more about the workflow than quality. If you need to make many Espressos in quick succession you'll hit the limits of cheaper equipment.
Although surely you would need to make the steam from steamed steam for optimal results?
Well, it's a complex question. I'd suggest to start from plotting your favorite coffee hardware brands and barista youtubers/tiktokers over the phase diagram of water, and continue from there.
Once you get comfortable with thinking about coffee in Scientific Terms, one avenue to explore is to try and embed the aforementioned phase/opinion water diagram plane into the larger Great Material Continuum hyperspace. To do that, you add a third axis: price (for hardware obviously by MSRP/catalog price; for vloggers, plot specific tips or steps by price of ingredients they use).
Having done that, you should have all the tools needed to make informed decisions in this space - just compare the paths water takes through this enriched 3D phase diagram as it turns into steam and then your beverage using any given method and combination of equipment :).
Waiting for him to appear in the YouTube shorts Brooklyn Coffee shop now I think about it.
His presentation still is still a bit forced and orchestrated to me, but at least I believe he’s smart and has interest in the craft.
Doran and Chris also host a podcast called Coffee Literature Review, where they invite a guest from the coffee industry and discuss a scientific paper connected to coffee somehow: https://podcasts.apple.com/us/podcast/coffee-literature-revi...
At the SCA Expo a few years ago, they were doing electrochemistry on brewed coffee to measure caffeine content, and also change the flavor in weird ways. This latest paper seems to build on previous experiments in a similar vein: https://sca.coffee/sca-news/25/issue-18/amped-up-using-elect...
For those who are as ignorant as I https://en.wikipedia.org/wiki/Cyclic_voltammetry