okay. thanks ladies:) @sarahdrew @dessamarie @annanichole

if you let the freshly expressed milk come to the same temp as the previously expressed, I used to do it all the time, I would put the container in the fridge for a couple hours then combine them....

it has to be same temperature to mix it together, if it's not then it will ruin it

could be same container as long as both are room temperature ,iff you put it on the fridge then no