I typically drink light roast single origin coffees from a third wave coffee roaster.
I'm brewing with either plunger/french press, or swiss gold filter.
Often with the french press, the coffee will taste quite sour.
I suspect that this isn't just how the beans taste, other times it will taste quite good.
Any idea what causes a coffee to taste sour?
Best Answer
Excessively sour flavor in your coffee brew is a likely sign of underextraction, i.e. the coffee has not brewed long enough and has an excess of acids. Acids are extracted early in the brewing process, whereas other balancing flavors are extracted later in the process.
Per Wikipedia:
Making good coffee involves a multitude of factors, and it can take some trial & error to hit the sweet spot. But let's mention the major ones:
For your case, I'll just call out the most obvious thing: Because you're using a French press, you have to use a coarser grind than something like a drip machine requires. Those larger coffee grains are going to require more extraction time.
So it could be that it simply needs to steep a little longer before pushing down the plunger. I personally like to give my coffee a stir for about a minute after pouring in the water to help encourage thorough extraction.
Hopefully some experimentation along those lines will help you achieve the perfect cup. Happy caffeinating!