I want to talk about acid.
First: how do we detect it? As a point of reference, imagine biting into a lemon, or having a mouthful of proper lemonade. Picture how your mouth would fill with saliva.
Now have a big slurp of wine and having swallowed, tilt your head forward with your mouth open. Looks disgusting - maybe best to try this one on your own first. But once you’ve got past the weirdness you’ll notice your mouth filling with saliva - just like it would with the lemon.
As a general rule of thumb, white wine is more acidic than red wine. But sweet wine is even more acidic than white wine. I say ‘but’ in bold italics because it highlights an issue with perception. Sweet wines often don’t seem that acidic, because the high levels of sugar are balancing the taste in your mouth. Lots of the other wine components can make acidic wines feel less acidic than they actually are.
Grapes all start off with high levels of acidity, but as they ripen, the acidity reduces. This is where climate comes in: cooler climates (like Britain or northern France) will ripen less and thus be more acidic, while hot climates like the south of Spain will be less acidic.