A Food Scientist- and mom- weighs in

by Milk Drunk Content Team and Viji Ganesh, a Food Scientist, Product Researcher, and mama to a baby boy.

“Ready to feed (RTF) liquid formula or powder formula?” How is a sleep-deprived new parent with a hungry baby and very little time supposed to choose?

With so many options and opinions, there’s a lot of confusion around the key differences when it comes to these formulas and how they might impact your baby. We took a look at some of the pros and cons of each to help you make an informed decision.

The Gist

Powder and liquid formulas are very similar when it comes to nutritional output, but some small differences in ingredients can support improved digestibility and tolerance.

Why liquids are becoming less popular

While liquid formulas were very popular for many decades, they are becoming less so every year. Once perceived to be ‘fresher’ and ‘closer to breast milk,’ a recent industry report branded them outdated due to a lack of ingredient varieties and options for babies with specific special dietary needs, stating: “Unless innovation hits liquid formula hard, American consumers are likely to continue reaching for powder varieties.”

Although there are more options when it comes to powder and liquid formulas are more expensive, regulations ensure that they deliver similar nutritional value. Both have been proven to sustain normal growth and be tolerated by babies.

Key scientific comparisons

In terms of research, there’s only been a few comparison studies and most were done on animals, which carry less weight from an evidence standpoint. That said, they’ve delivered some interesting results:

  • A 1989 comparison on rats showed that the manufacturing process for liquid formula resulted in fewer digestible proteins and essential amino acids available for absorption.
  • A 1998 clinical study showed comparable growth, hemoglobin, ferritin, zinc, and copper levels in breast-fed term infants or those fed either types of formula.
  • Another 1999 rat study showed that tryptophan, an important amino acid, wasn’t as well absorbed from liquid formulas compared to powder.

Science aside, there are other factors that influence parents when it comes to selecting which type of formula to purchase.

Tradeoffs between liquid and powder formulas

  • Convenience: For some parents, the convenience of being able to ‘pour and feed’ makes liquid worth the extra cost.
  • Commercially sterile: Liquids are the preferred choice for premature or sick babies because manufacturing these formulas involves higher heat and contamination-free packaging to ensure they’re commercially sterile. Powder formulas rely on rigorous manufacturing and safety testing to avoid contamination.
  • Probiotics: The downside to liquid formulas being sterile is they cannot sustain probiotics.
  • Shelf life: Once you open a liquid formula, it can only be stored in the fridge for about 24-48 hours, while powder formula is fresh for up to one month after opening.
  • Texture: Controversial stabilizers and emulsifiers give liquid formulas a very smooth consistency that often appeals more to babies. However, there are tricks in our tips below to recreate this with powder.

Expert Q&A

Viji Ganesh, Food Scientist and Product Researcher talks about the difference between liquid vs. powder formula.

The Milk Drunk Content Team sat down with Food Scientist and Product Researcher, Viji Ganesh. She also sits on the Mother Board of bobbie as the Lead Product Scientist.

Milk Drunk: Why are so many babies gassy after switching from RTF to powder formula?

Viji: Air bubbles that gather during the formula preparation process can cause a baby to feel gassy. Liquid formulas don’t have probiotics but many powder formulas now do. It’s very common for probiotics to cause more gas initially, which is why you should make the switch gradually. Most babies’ microbiome and palates will eventually adjust. If you’re also nursing, you should talk to your doctor about the best ways to introduce any formula into your baby’s unique diet.

Milk Drunk: If you’re new to supplementing, would you choose a liquid or powder?

Viji: It really depends on your baby’s needs and your lifestyle. Most parents of healthy, full-term babies choose powder because it’s more cost effective and has a lot of cutting edge ingredients like probiotics. Milk-based liquid formula costs on average more than 7 cents per oz milk-based powder formula so the cost can add up quickly. If you’re breastfeeding, you should always talk to your doctor about the best ways to introduce any formula into your baby’s unique diet.

Milk Drunk: What’s the best type of water to use when making formula and why does it matter?

Viji: Babies have very sensitive immune systems that need to be protected from bad bacteria, like Cronobacter. If you are not sure if your cold tap water is safe, check with your local health department. Boil your cold tap water for one minute before quickly cooling it to body temperature. Pour it into a sterilized bottle and add the correct amount of formula. Ask your baby’s pediatrician before using filtered, purified, or bottled water.


  • Read labels: Know what ingredients your baby is consuming.
  • Prepare ahead: Make and refrigerate powder formula ahead of time to allow the freshly-shaken bubbles and foam to settle. 
  • Gas drops: If your doctor is OK with it, add gas drops to powder formula to eliminate foam for a smoother texture.
  • Introduce slowly: When using a new formula, your baby’s gut may need time to adjust. 
  • Stay consistent: Keep other things in your baby’s routine the same when using a new formula so you can easily identify any issues.


Viji Ganesh is a lead product scientist at Bobbie. Her key roles include product development in collaboration with other experts in infant nutrition, quality and safety testing, and building team expertise. She holds a Masters in Food Science and a Bachelors in Biotechnology, with 10+ years in lab and industrial research & development.

Viji Ganesh

Viji as a food scientist with experience in infant nutrition. She holds a Masters in Food Science and a Bachelors in Biotechnology, with 12+ years in lab and industrial R&D/ product development. Products of significance that have seen the journey of formulation through commercialization include infant formula and cultured products (cheese, yogurts and probiotic drinks). As a mom of two girls, Viji truly believes that 'ingredients matter' and that starts with the child's first nutrition.

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