Stonybrook Yogurt

I found some vintage yogurt in the back of my fridge from 1984 and I am somewhat convinced this kind of thing has fermented. Raspberry Yogurt is it Stonybrook Farms brand of the year 1984, the expiration date is August 13.
Do I now cheese? If I have cheese, what kind? Is that rare or limited edition cheese? Can I sell them for money?

Tell all you can see the face of Jesus in him and someone will buy it on eBay.

Why would you leave the yogurt in the fridge for 25 years without knowing if it turns to cheese is my first question for you lol
I hope its worth something to you, but I could not tell you