Let’s see….

mods/ITEMS/mcl_sweet_berry/init.lua

@@ -25,6 +25,12 @@ for i=1, 4 do
  		sunlight_propagates = true,
  		paramtype2 = "meshoptions",
  		place_param2 = 3,
+        liquid_viscosity = 14,
+     	liquidtype = "source",
+     	liquid_alternative_flowing = "mcl_core:cobweb",
+     	liquid_alternative_source = "mcl_core:cobweb",
+     	liquid_renewable = false,
+     	liquid_range = 0,
  		walkable = false,
  		drawtype = "plantlike",
  		drop = "mcl_sweet_berry:sweet_berry",