How to Prepare Your Baby's Formula

This guide walks you through preparing, storing and serving every formula we carry, safely and step by step.

Breast milk is best for babies. Please talk to your pediatrician before starting or switching formula.

Jump to: Preparing powdered formula · Ready-to-feed bottles · Our formulas · Specialized formulas · Safety · Storing prepared formula

Which formulas does this guide cover? Cow's milk formulas, goat's milk formulas, plant-based formulas (Sprout Organic®), specialized formulas, and ready-to-feed bottles.

The most important rule: always follow the instructions on your tin or box exactly. Water temperature, scoop sizes and water amounts differ between brands and stages, and manufacturers can update them at any time.

Preparing Powdered Formula

1. Clean and sterilize 🧼

Wash and dry your hands. Wash all bottles, nipples and caps, then sterilize them by boiling for 3 to 5 minutes, or with a sterilizer.

2. Boil and cool the water 💧

Boil fresh water, then let it cool to the temperature shown on your tin. Measure the exact amount of water from the feeding chart on your tin and pour it into the bottle.

3. Add the powder 🥄

Use only the scoop that comes with your formula. Fill it and level it with the back of a clean knife. Add the exact number of scoops shown on your tin.

4. Mix 🍼

Close the bottle with a sterilized cap and shake until the powder has fully dissolved and no lumps remain. Placing a cap over the nipple helps you avoid touching it.

5. Check the temperature 🌡️

Cool the bottle to body temperature, for example by holding it under cold running water. Test a few drops on the inside of your wrist: it should feel warm, not hot. Feed straight away.

Ready-to-Feed Bottles

Ready-to-feed formula is already mixed, so never add water or powder. Shake well, pour into a sterilized bottle or attach a sterilized nipple, and feed at room temperature or gently warmed. Check the label for how long an opened bottle can be kept.

Our Formulas

Open your formula's product page for its feeding chart, and always check the tin itself.

🐄 Cow's milk formulas

Shop cow's milk formulas →

🐐 Goat's milk formulas

Shop goat's milk formulas →

🌱 Plant-based formulas

  • Sprout Organic®: Infant Formula (0–12 months, 800g tin and 176g pouch), Toddler Drink (12+ months), Essential Shake Vanilla and Chocolate (12+ months)

Shop Sprout Organic® →

🧃 Ready-to-feed

Specialized Formulas: What to Expect

HA (partially hydrolyzed), comfort and anti-reflux formulas can look, smell or taste a little different from standard formulas. Anti-reflux formulas are thicker by design. A few tips:

  • Offer the first bottle when your baby is hungry, and stay relaxed. Babies pick up on your reactions.
  • For thicker formulas, a variable-flow or larger nipple helps the formula flow.
  • Older babies may prefer a covered cup.
  • Follow your tin's instructions exactly, including the water temperature.

If you're unsure whether something is normal, contact us or your pediatrician. Browse sensitive and specialized formulas →

Important Safety Information ⚠️

  • Only use the scoop that comes with your formula.
  • Never make bottles stronger or weaker by adding extra powder or water, and don't add anything else to the bottle.
  • Never heat a bottle in the microwave. It heats unevenly and can cause scalding hot spots.
  • Never use formula past its expiry date. European and Australian tins print dates as day/month/year.
  • Store tins in a cool, dry place, away from heat and humidity, and close them tightly after use.

Storing Prepared Formula

🧊 Freshly made, not yet fed

Use within 2 hours at room temperature, or within 24 hours if stored in the fridge, unless your tin says otherwise.

🍼 Once your baby has started feeding

Finish within 1 hour, then throw away what's left. Never put a bottle back in the fridge after feeding, because bacteria from your baby's mouth can keep multiplying.

Questions?

Manufacturers can change packaging, sizes or instructions at any time. Always follow the instructions on your packaging, even if they differ from this guide.

Our team is happy to help at hello@themilkybox.com or on live chat, Monday to Friday, 8 am–5 pm CST. You can also find answers in our FAQ.

Breast milk is best for babies. The information on this page is educational and not medical advice. Please talk to your pediatrician before starting or switching formula.