What’s the Best Water for Preparing Baby Formula?

At Little Bundle, we’re raising the bar on child nutrition by providing the highest quality baby formulas available. But choosing the right formula is only the first part of the equation. Once you've chosen the best formula for your baby, you need to prepare the formula. When parents reach this stage of the process, they often ask us an important question: 

What’s the best water for baby formula?

This guide will help you understand what water to use for your formula and how to prepare it.

The Best Water for Your Baby's Formula

Regardless of your water source, we recommend that you always boil your water before mixing it with formula. Doing so will kill any harmful bacteria that may be present in the water or formula powder, while still keeping as many minerals in the water as possible.

Tap Water

Tap water provides a convenient, safe option, as long as the water has not been sitting out before use. Most tap water contains added fluoride to prevent tooth decay. However, too much fluoride can lead to enamel fluorosis in children, which causes white streaks on their teeth. 

Many parents alternate between fluoridated tap water and distilled or filtered water. It's also best if the fluoride level in your water is below 0.7 mg per liter. You can call your city or enter your zip code here to learn more about the safety and quality of the water in your area. 

Bottled Water 

When you're out and about or don't have access to other options, bottled water can be useful for mixing with formula. It's especially helpful when traveling and unfamiliar with the safety of the local water supply. For your baby, it's best to choose bottled water that is low in both sodium (less than 200 mg per liter) and sulfate (less than 250 mg per liter).

Filtered Water (And How to Filter It)

You can also use filtered water in your baby's formula. You can easily find water pitchers that are made with quick water filtration systems. It is critical that you change the filter as often as the product instructs in order to keep your water pure. 

Different types of filtration systems filter different contaminants. This graphic from the Environmental Working Group (EWG) is a great resource to quickly determine which kind of filter is best, depending on your needs. 

For example, to filter out fluoride, you need a filter with a water purification process specifically created to effectively remove fluoride and other unwanted particles from your water. 

Steps to Prepare Baby Formula

So now that you’ve chosen a water source based on your situation and needs, you need to prepare the formula in a safe and reliable manner. There are three basic steps in this process.

Step 1: Boiling the Water

First, wash your hands and sterilize all equipment. Bring at least one quart (approximately one liter) of water to a rolling boil for one minute to ensure there aren’t any contaminants. Leave the water to cool down to at least 104 degrees Fahrenheit before mixing. Make sure the water is not left out for more than 30 minutes.

Step 2: Mixing the Formula

It's important that you always closely follow the instructions on the formula packaging. After boiling water, add the desired amount of water to a bottle. Then add the corresponding amount of formula powder using the scoop included in the package. This Formula Feeding Chart provides clear guidelines on the amount of water and formula powder to use in your baby's bottle at various stages of growth. 

Place the nipple and lid on the bottle, then shake for about 15 seconds to mix in the powder until it is completely dissolved. Before handing to your baby, ensure the formula has cooled to around body temperature (98.6°F). 

You can test the temperature by putting a few drops on the inside of your wrist. It should feel warm, but not hot. If it needs more cooling, run it under cold water or place it in the refrigerator. Once ready, give the bottle to your baby immediately.

Step 3: Storing Prepared Formula

If there is any remaining formula in the bottle, it must be discarded within one hour from the beginning of a feeding, as the bacteria from your baby's mouth can still grow in the refrigerator. 

You can, however, prepare formula and then store it to give to your baby later by following these guidelines for proper storage:

  • At room temperature, a bottle can be left out no longer than two hours.
  • In a cooler or ice pack, a bottle can be stored for four hours. 
  • In the refrigerator, a bottle can be stored for no more than 24 hours. 
  • Never freeze prepared baby formula. 

It is safe to give your baby room temperature or cold formula. However, some babies prefer it warm. Never use a microwave to warm formula, as it can cause hot spots that could burn your child's mouth. Instead, place the bottle in a bowl filled with warm water for a few minutes.

Safe Nutrition for Your Baby

Babies are constantly learning and growing, so they need a lot of energy to keep up the pace. With the right knowledge, clean equipment, pure water, and nutritious formula, you're ready to provide the absolute best fuel for your precious little one.

We're here to help.

Still feeling a little unsure? Use our live chat, or send us a message. Our top priority is to help make finding and preparing the right formula for your little one as easy and stress-free as possible.