I always added the milk at time of feeding - I make up my btls for the day and keep them in the fridge so just took a little of one if I needed it. However, I always found that once defrosted the puree was a bit more runny anyway. Let it defrost first, then heat it up and give it a good stir. If you need milk, add it at this point and see how it looks. If I was really behind sched or just not on top of things and had no milk handy I would just add a drop of hot water. Hope he likes it. My two were very hit and miss in the beginning but they are eating me out of house and home now... Trisha.