You could try letting it culture longer. For that type of yogurt making, some people seem to have more luck with letting it culture for 24 hours. It might improve the flavor.
Just curious...why are you using both yogurt from a previous batch and yogurt from the store? Normally it's just one or the other.
Just curious...why are you using both yogurt from a previous batch and yogurt from the store? Normally it's just one or the other.