MilkBank delivers the freshest breast milk possible, and fresh breast milk is the most nutritious for your baby. Clinical tests show that any level of oxygen exposure begins to spoil breast milk. For best nutrition, freshly pumped breast milk should be fed immediately or stored in MilkBank's vacuum sealed storage bottles for later feeding. Traditional storage methods, such as bags and bottles, trap harmful oxygen when sealed. This exposure to oxygen not only impacts the nutritional value, but can also distort the flavor, causing babies to reject stored breast milk.