Using a Breast Pump A breast pump is an important piece of equipment for the breastfeeding mom who wants to increase her supply or store pumped breast milk. While it seems like a simple thing to sit down and pump out milk, there are things you can do to make pumping more effective. Storing Your Breast Milk Glass or hard plastic containers are the best storage containers for human milk, especially if it is to be frozen and stored for weeks or months. Thawing Breast Milk Use the oldest milk first, and thaw it by placing the collection container in the refrigerator for several hours or overnight. Taking Care of Your Breast Pump and Collection Kit Moms who bottle feed their babies are always worried about keeping the bottles and nipples clean and sterilized at all times. Likewise, if you’re a breastfeeding mom you have to be concerned with keeping your breast pump and all its parts clean to keep your baby safe from breast milk contamination.