Praise be to Allah the Lord of the Worlds.
Suckled milk establishes the prohibition for marriage (Suckled baby becomes the son of the suckling woman), even if its condition has changed or was preserved by a certain method since jurists don`t stipulate that the milk remain in its normal form. This is because the Illah (Cause) for this prohibition is that the milk is nutritious, so the prohibition is valid as long as the cause stands.
Al-Shirbini says: "If a woman had milked herself prior to her death and her milk was given to the baby after she passed away then she becomes prohibited for him in marriage according to our-Shafie-more correct opinion, because the milk was separated from her. Moreover, it isn`t conditioned that the milk maintains its normal form. Therefore, if it was made into cheese, butter or mixed with wheat and given to the baby then the baby remains the son of that woman, because the milk is nutritious." {Moghni al-mohtaj, vol.5, pp.125}.
The prohibition for marriage owing to fosterageis established in line with the following conditions:
The suckled baby is no more than two years old and was suckled for five separate times. Thus, if the suckling woman dropped her milk in a pot and gave it to the baby then the prohibition for marriage owing to fosterage is also established, but it is conditioned that the milk is milked on five separate occasions and given to the child on five separate occasions as well. In addition, it is allowed that the amount fed to him each time is small. Al-Shirbini says, in this regard: "If she was milked five separate times and were given to the child on five separate times without mixing them then they are considered five instances of suckling." {Moghni Al-Mohtaj, vol.5, pp.136}. And Allah the Almighty Knows Best.