Infant Formula 101: Preparation

Tycho, around four months, enjoying breakfast!

Despite the fact that I breastfeed Tycho on the regular now, there are still some times when I need to supplement with a bottle of formula. Like when I was sick: That entire week, my pump output was about four ounces (or one full bottle) under what I needed to make per day, so Tycho was sent to daycare with two breastmilk bottles and one carefully prepared soy formula bottle. And y’all know that we exclusively formula-fed Tycho for a number of months, so this isn’t new territory!

When we started formula-feeding, we were a bit disappointed by how little information there was about safe formula handling. Of course, there were the instructions on the side of the can, but what about other questions? How long can I keep it in the fridge, can I mix old formula with new, can I mix breastmilk and formula? What bottle is best? What if my baby is allergic or sensitive to the formula I’m using?

Because there are so many questions, I thought I’d do a series on proper infant formula preparation. Today’s will focus on mixing bottles; others in this series will include information on bottle selection, allergies and other reactions to look out for, and frequently asked questions. I hope you find this helpful!

(Thank you to Fearless Formula Feeder for much of today's information!!)

Mixing Bottles

It may seem as simple as mixing powder and water, and to some extent, it really is. But it can sometimes be a little tricky, especially when it comes to preparing formula for a newborn, who needs special consideration and care when it comes to sterile environments and the type of water used.

As a result, these tips are split into two categories: Formula preparation for the newborn, and formula preparation for babies three months and older. Blissfully, instructions on formula prep for older babies is shorter. I’m going to include my own tips as well, as we’ve found ways to handle those 3am wake-ups without much issue!

First and foremost: Read the can you’re using. No, seriously. READ THE FREAKIN’ CAN. I tell you this for good reason. I’ll explain later why this is the case, but in short, different formulations use different types of scoops, terminology, and methodology, and you do NOT want to confuse yourself. READ THE CAN.

And WASH YOUR FREAKIN’ HANDS. Every time. No matter what.

Mixing Formula for Newborns

FIRST: Consider ready-to-feed formula for your infant. It’s safe, easy to use, and less chance of contamination as you just pour it into a bottle or use the nipple that’s provided. It is expensive, sometimes prohibitively so, but if you’re particularly worried and want to go the easier route, RTF formulas may be right for you.

If you decide to go with traditional powder formula:

1. Measure the water. No duh, right? But it’s not just about measuring correctly, it’s also about the type of water you use. For newborns, your best bet is bottled distilled water. If you don’t have any available, boil a batch of water on the stove, let it cool, and keep that in the fridge. Do not use straight tap water or even home-filtered water until baby is at least three months old.

* “Nursery water”, by the way, is typically fortified with fluoride, which may or may not be good. Check out this post from the Fearless Formula Feeder for more information on nursery water.

2. Measure the formula. And again, READ THE FREAKIN’ CAN to find out how much formula to use per number of ounces of water. Use the scoop that is provided in the can; don’t try to use different scoops, as they can vary between formula companies and even types of formula under the same company umbrella. The ratio is typically one scoop (packed or unpacked, depending on the FREAKIN’ CAN) to two ounces of water. An exception is Neocate, an amino acid-based formula, which uses one formula scoop to one ounce of water. Reading the (ahem, FREAKIN’) can... you can’t go wrong.

So yes, if you’re making a 4oz bottle, with the exception of Neocate, use two scoops; if you’re making 6oz, use three scoops; and so on. Making an odd number of ounces is a bit trickier; you can eyeball a half-scoop, but this isn’t an exact science, and I wouldn’t recommend it for a newborn. Instead, make more formula than you need, pour into separate bottles, and refrigerate the other for later use, always within 24 hours of mixing. We’ve done this a few times, especially when preparing them for daycare: We’d make 10oz of formula, shake it all up, and pour into two five-ounce servings. Voila!

3. Prepare the bottle as needed. Some are as easy as screwing on a nipple, but others – Dr. Brown’s (especially), Avent, and Born Free are a few off the top of my head – need little doo-dads to work properly. Be sure to read the pamphlets that come with each bottle for proper use.

4. Shake, shake, shake! Once all is assembled, cap the bottle or put your finger over the nipple hole, and shake vigorously. You want no clumps to remain, so you’ll really need to shake for a bit. Place the bottle on a flat surface and allow it to settle before serving. Before giving to baby, make sure there are no clumps of formula in or near the nipple; this actually happens a lot, and can block free flow to your baby.

You can also use a formula mixer/pitcher, which is supposed to mix the formula more smoothly. Since it’s recommended that you make each bottle separately right before feeding, though, and since we’re being uber-careful because we’re talking about a newborn, I’ll get to the pitcher later.

5. Feed that bottle within two hours of mixing, unless refrigerated for later use. If refrigerated, the bottle will be good for 24 hours, but anything at room temperature needs to be used within two hours. This is especially important with newborns, as bacteria can form (albeit slowly, but it happens!) and cause a lot of nasty issues, so you want to be diligent when it comes to a baby under three months.

Once the bottle touches baby’s lips, by the way, that bottle must be used within two hours, even if refrigerated. The reasoning is the bacteria issue again: There will be additional bacteria introduced once baby starts eating from the bottle, so it must be used to avoid the risk of multiplication to a point that may be dangerous. So yeah, use that bottle first!

Mixing Formula for Older Babies (3+ Months)

Told you they’re going to get shorter. :)

1. Pour the water. No need for boiled or distilled at this point, though you can certainly keep using them! Bottled, tap (so long as it’s from a safe source), or filtered water works just fine. Be sure to keep that filter up to date, though. We invested in one of the huge Brita jugs when we switched to formula.

2. Scoop the formula. As always, READ THE FREAKIN’ CAN, especially if you switched formulas recently. But the same rule usually applies as before: One scoop to two ounces of water. You can start eyeballing for odd-numbered ounces now, but I'd still recommend doubling and saving.

Now you can happily bring in a formula pitcher! This thing saved our lives when we were preparing a whole day’s worth of formula at a time. You pour in as much water as you need (in our case, we were preparing four 4oz bottles, so 16oz of water), then add as many scoops as you need (again, in our case, 8 scoops). Count out the scoops carefully, though; I’ve had to tell Matt to STFU several times while preparing, as I have had to throw out formula due to losing count of how many scoops I put in (yes, I cried over that lost milk). And of course, he sometimes made my job even harder by throwing random numbers in while I was counting. He prepared formula for a while after that. :P

We used the Dr. Brown’s formula mixer, but you can use whatever brand you fancy. And be sure to refrigerate anything you don’t use and to use whatever is in that pitcher within 24 hours.

3. Shake or mix. Still going by the individual bottle? Make sure there are no clumps or anything, same as before. Allow the bottle to settle before serving, as there may be air bubbles still left over. If you use infant gas drops like Mylicon, now is the time to add them to the bottle.

Favorite Tools

Formula dispensers! This was my favorite tip for middle-of-the-night feeds. We discovered this shortly after we needed to start formula, and it has been a lifesaver, seriously: Premeasure water into bottles, buy a formula dispenser (we used these canisters), and measure out your formula into those dispensers. When you need to feed baby, simply pour the premeasured formula into the premeasured water, shake, and serve. No more measuring while half-asleep!

This tip also works well for outings. No need to bring a cooler or anything, just the bottles and the canisters. We used this trick a lot when traveling, especially through airport security, when the last thing you need is to haul the whole can.

And of course, I already mentioned the formula mixer. Love it. Absolutely love it.

One Last Word...

While these instructions seem a bit daunting at first, I promise you, it’s really not. All this stuff becomes rote after a very short period, and soon you won’t even need to double- and triple-check the can before prepping a bottle. But there are some instances of something going wrong, and it’s typically due to improper handling that leads to issues such as bacteria and dehydration, so it’s always better safe than sorry. Read the (FREAKIN’) can, follow directions, wash your hands, and be confident! You’ll be great, I promise. :)