We have 20 blueberry bushes at least 30 years old. They always produced wonderful blueberries until this year. There was a smaller than usual crop and sour - even the biggest darkest blue ones... We are in Buffalo, NY - we had good weather, rain and sun... our veggies are great but not the blueberries...

Our bushes are mulched with pine and fertilized with horse manure - which we have done for years !
Anyone else experience this?

Ours (a couple of bushes) just did not form berries at all.

The berries at the local farm where I pick were a bit late and slow to ripen, but they tasted awesome! Especially the last batch I picked! I've never grown them, so don't know what might have happened. As a child (100 years ago in the olden days) ,I used to pick wild blueberries in the woods near my house. There was always enough for eating, muffins, and pies. It was a different world then.

My son lives on a 5,000 bush blueberry farm....they have 19 varieties......some were very sweet this year, but I noticed the earliest ones were tart, the latest ones were the sweetest.......don't know if it's the variety, or whether the temps went into the high 80s-low 90s, while early July was rather chilly, especially at night......the farm did open a week later than usual.