blueberries coffe ground and tea leaves

Is it true that coffee grounds and tea leaves make the soil more acid hence it is good for blueberries?

I just read recently that coffee grounds aren't terribly acidic - the acid is leached out into the coffee you brew, so they're actually fairly neutral and can be used as a soil amendment up to concentrations of 1/3 with good results.

That said, they are a nutritious addition to your soil, so I don't think the blueberries will complain. You just aren't likely to get a big pH adjustment out of it.

Here's one of the things I read: http://www.sunset.com/garden/earth-friendly/starbucks-coffee-compost-test Their analysis put spent Starbucks grounds at a pH of 6.2.

Yes, a little....better to use Pine needles or beech leaves !!

I use pine needles, but isn't tea more acid?