i want to add blueberries, from info on this forum it looks like i can add at second ferment stage, i am at that stage now but i see people are saying to add as an f-pac, i dont know what this means, i dont know if i need to add more yeast with it as someone mentioned that it is hard to ferment blueberries, bit confused but wanty to add blueberries. just dont want to do wrong. i am doing a 23 litre cellar craft cab sav. thanks people.