Does anyone know of a simple diagram or chart showing the effects of key parameters on an espresso shot?

eg.
Finer grind results in slower extraction rate.
Coarser grind results in faster extraction rate.
Faster extraction rate results in overextraction.
Slower extraction rate results in underextraction.
Higher temp=Bitter
Lower temp=Bright

These are not entirely correct or definitive, but I'm hoping I can find a chart that can be an easy guide for beginners. something along that line. TIA

I think you're talking about this chart while adding a vertical scale for temperature, although the chart below may suffice for basics of fine tuning.



The chart is posted here:

Espresso 101: How to Adjust Dose and Grind Setting by Taste

and here:

Adjusting flow rather than dose & grind

In practice I think it's a bit more complex than this as you try to bring forward desirable flavors and de-emphasize undesirable ones. Some coffees and blends will have at least two favorable combinations of variables. And some similar tastes can be extracted at different temperatures. For instance too high a temperature will extract bitterness but that can also happen at too low a temp. Reading some of the yearly favorite espresso reviews will show those considerations.

I believe some adjustments are gross parameters. For instance, if you're dialing in an espresso it helps to brew it first. This will allow you to dial in temperature and dose. There are also windows for aging. For brewing that's more variable. An example is emphasizing higher notes like spice and florals by brewing very soon after the roast. That shot won't taste like much for espresso because it won't have middle or bottom notes that are obscured by CO2. There's a window for the widest spectrum of flavors. Then it goes flat with high notes disappearing first.

Then there's pressure profiling that uses flow for emphasis and de-emphasis. High pressure at first will maximize high notes without overextracting. A declining pressure profile will slow flow rate and avoid overextraction.

perfect. Thanks DrGary!

I like the idea of perhaps putting together some "espresso 201" descriptions and diagrams to explain the effects of things like pressure profiles and preinfusion, and what flavors they tend to enhance or bury.

Drgary's description of coffee as it ages was very good too and helps me explain why I have some coffees that don't even taste good until a week out, but my Harrar as such a small window of usable time as an enjoyable SO berry bomb.