I wouldn't suggest using glass bottles to freeze baby food either. They shatter very easily when they go from cold to hot or vice versa. Also, the food tends to expand as it freezes so if there is no room for it to expand it will shatter also.
I freeze the food in ice cube trays also. You can also do the "plop" method where you plop spoonfuls on a cookie sheet and put that in the freezer. Once they're frozen, just put them into freezer bags.
lilysmommie