Here's a recipe for a partial mash apricot sour beer that you just add lactic acid too to provide some simple sourness. You could use a different fruit I'm sure.
Brewhouse efficiency: 72%
ABV (est): 5.4%
1 lb (454 g) Vienna
1 lb (454 g) Carafoam
8 lb (3.6 kg) Pilsner liquid malt extract
HOPS & ADDITIONS SCHEDULE
0.5 oz (14 g) Strisslepalt at 60 minutes
2 fl oz (59 ml) Apricot Extract or to taste
Mash the Vienna malt and Carafoam at 159°F (71°C) for 15 minutes. Add food-grade lactic acid to achieve a pH of 4.0 (about 1 fl oz/33ml). Add the malt extract and boil for 60 minutes, following the hops schedule. Ferment at 68°F (20°C) until final gravity is reached. Add the apricot extract, then package as normal.