Preparation before you begin to pump your breastmilk

1. Hand Washing

This has got to become a habit. Soap and water or a waterless hand cleanser if washing is not an option before you begin to express your milk. Viruses and bacteria on your hands can cause illness in you and your baby as well as increase the chances of bacteria growing in your milk during storage. TIP: Studies show that mother’s milk containing fewer bacteria at the time of expression has higher protein levels.

2. Pump Washing

Whether you express your milk by hand or by pump, hand cleansing and the cleaning of pump parts as per the pump manufacturer's instructions is critical to avoid contamination of your expressed milk. In addition, the CDC has developed an easy to understand chart with excellent graphics, displaying the newest guidelines.  

Read it, print it and post it. https://www.cdc.gov/healthywater/pdf/hygiene/breast-pump-fact-sheet.pdf

TIP: Research shows there does not seem to be a difference in milk contamination with pumping versus hand expression.

3. Storage Container Choice

Several studies have shown a significant reduction of fat and fat-soluble nutrients (think immune factors as well as your milk’s anti-bactericidal properties) with glass or polyethylene, polypropylene, polycarbonate, or polyethersulfone bottles as well as dedicated breastmilk storage bags. Be sure that the plastic bags that you do choose are designed to hold breastmilk. They have to be well sealed and kept in an area of the freezer where they will not be damaged.

TIP: The fatty part of your milk will adhere to the inside of any container. Try to feed directly from the collecting container to get all your milk’s value into your baby. This company has the right idea. https://www.kiinde.com/twist_product.php

4. Container Care

Containers for breastmilk storage must be taken apart, washed in hot soapy water and rinsed or washed in a dishwasher. They should always be thoroughly air dried or dried with paper towels. They do not need to be sterilized if hot soapy water is used. If soap is not available, then submersion in boiling water should be used. TIP: Look for bags with a pleated bottom that will stand up on their own to avoid spills and subsequent crying.

Storage after you have pumped your breastmilk

5. Room Temperature

Freshly expressed breastmilk can be stored safely at room temperature (10–29°C, 50–85°F). Studies suggest different lengths of time for room temperature storage because conditions can vary greatly. Warmer temperatures = faster growing bacterial counts in stored milk. Somewhere between 4 – 8 hours is the current guideline, depending on the variables. TIP: It’s best to chill or refrigerate your expressed milk as soon as possible if your baby is not going to drink it within a few hours after pumping.

6. Ice Packs

Very few studies have evaluated milk storage safety at 15°C (59°F), which would be equivalent to an ice pack in a small cooler. One study suggested that pumped breastmilk is safe at 15°C for 24 hours, based on the minimal bacterial growth noted in their samples.

7. Refrigeration

Several studies have measured the bacterial growth in stored, refrigerated breastmilk at 4°C, 39.2°F.  Once again, many factors determine the length of storage time at which your breastmilk begins to degrade. Higher levels of bacteria in your milk at the time of pumping = a 48 - 72 hr time limit.  Another study of breastmilk with little contamination at the time of expression showed safe, low levels of bacteria growth in milk even after 4–8 days of refrigeration. TIP: See #1 & #2.