Fresh Squeezed

Fresh Perspectives

Real stories and data from families navigating challenges with milk storage.

How often do parents notice changes in stored milk, and what happens when they do? In a nationally representative survey, we found that ~30% of parents reported a noticeable change in taste, smell, or both. Of the stored milk for which parents noticed a change, ~50% was rejected to some degree.

A note on “high lipase”: Families often use this phrase to describe when stored milk smells or tastes different and their baby rejects it. Because there is no commercial lipase test or accepted threshold for what means "high", we focused on measuring parent-observed outcomes instead.

Why it matters: For a meaningful share of families, feeding stored milk is a challenging, measurable part of the pumping experience, one that costs real ounces of hard-pumped milk.

Data available via ​Silpe et al. Foods 2025.

Company Updates

What's going on at PumpKin.

New Manuscript: Breastfeeding and the Environment

We explored the environmental footprint of infant feeding as part of a broader conversation about healthier, more climate-resilient food systems.

Key takeaways: Infant formula has environmental impacts through dairy production, processing, packaging, and transport. By contrast, breastfeeding requires fewer resources with a comparatively small footprint. When breastfeeding declines, reliance on infant formula can rise, increasing exposure to supply-chain disruptions and demand on resources.

PumpKin Co-Founder Awarded the Copley Medal

PumpKin co-founder Dr. Bonnie Bassler received the Copley Medal for discovering that chemical communication is universal among bacteria. Previous recipients include Albert Einstein, Stephen Hawking, Dorothy Hodgkin, and Charles Darwin. She is only the third woman to receive the award.

Bonnie currently leads a research lab at Princeton and serves as PumpKin’s Chief Scientific Advisor, helping guide our research and innovation.

What we're squeezin' this week.

A quick look at breastfeeding research and the conversations worth following.

Cross-functional leaders invited to help shape the future of mastitis research. 

Mastitis affects an estimated 15% of U.S. breastfeeding women and can lead some families to stop breastfeeding earlier than planned. Diagnosis and treatment can still be difficult. Guidance has evolved, but limited data leaves important questions unresolved and contributes to a lack of consensus among lactation professionals.

On Friday, October 16, PumpKin leadership will join clinicians, researchers, and patient representatives at a half-day Lactational Mastitis Research Summit hosted by the Academy of Breastfeeding Medicine and Vida Health. Participants will identify priority research questions to help strengthen the evidence that guides mastitis diagnosis and treatment.

Did you know?

Small molecules with big jobs in breast milk.

Each tiny droplet of fat in breast milk is surrounded by a natural coating called the milk fat globule membrane, or MFGM. This membrane helps keep the fat stable and carries phospholipids, proteins, and other bioactive components. Recent research suggests that the membrane's phospholipid composition changes across lactation, from colostrum to weaning, offering another example of how breast milk adapts over time rather than following one fixed recipe.

Closing thoughts

Bedazzled Breast Pumps at the Emmys.

Only Murders in the Building writer Taylor Cox brought a diamond-studded breast pump to the 2026 Emmys.

A practical reminder that pumping does not pause for awards night. The show didn’t win—but she didn’t get mastitis.