5 Parts of a Baby Bottle: Complete Guide for New Parents

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Baby bottles can be confusing, with lots of different bits and pieces to think about.

The most basic baby bottles have just three parts, but some can have as many as five or six.

It can be overwhelming for new parents!

Are complicated baby bottles with more parts better for our babies? Or do they just mean more things for parents to clean and assemble?

With so many types of baby bottles on the market to choose from, it can be hard to know where to start.

Understanding the different parts of a baby bottle is vital in choosing the best bottle for your baby, using it successfully, and keeping it clean.

This article will guide you through the different parts of a baby bottle, offering helpful tips that will ensure good hygiene, prevent leakages and keep your baby well-fed and comfortable.

Most baby bottles are made up of four or five different parts:

  1. Bottle: Holds the milk
  2. Nipple: Goes in the baby’s mouth
  3. Collar: Attaches the nipple to the bottle
  4. Cover: Prevents leakage from the nipple
  5. Anti-colic vent: Allows air to get into the bottle (on some bottles)

Let’s dive into each of these baby bottle parts so you can make the best choice for you and your little one.

1. Bottle 

Baby bottles come in all different shapes, sizes and materials.

Most have measurement markers which show you how much milk is in them. You’ll need these to know how much water to add to your scoops of formula.

For newborn babies, it’s also reassuring to know exactly how much milk your baby has consumed.

The best baby bottles are easy to clean, durable and non-toxic.

Baby bottle materials

At one time, all baby bottles were made of glass.

But when plastic baby bottles were invented in the 1970s, they soon became the norm.

Nowadays, with concerns over toxic chemicals, people are beginning to switch to other materials.

  • Plastic: Most baby bottles are made of plastic, but some parents choose to avoid them over concerns that microplastics and toxins can enter the milk
  • Glass: Easy to clean and long lasting, the downside to these is that they shatter if dropped. Silicone sleeves can protect glass bottles from breakage to some extent
  • Metal: Stainless steel baby bottles are durable and keep milk warm for longer. The major downside is that they are opaque so it’s hard to see how much milk is in them
  • Silicone: Relatively new to the market, silicone baby bottles are lightweight and shatterproof but they can be expensive

Baby bottle shapes

When choosing the shape of a baby bottle, think about if you’d ever use a bottle warmer or cup holders, and make sure that your choice will fit.

There are three main baby bottle shapes:

  • Tall and narrow: This is the standard shape that fits into most bottle warmers and stroller cup holders.
  • Short and wide: Wider bottles are easier to clean and have a shape that is closer to the shape of a breast.
  • Angled: Bent at the neck, angled bottles are designed to prevent air from entering the nipple.

For a lot more on materials and shapes of bottles, check out my guide to the different types of baby bottles.

Cleaning a baby bottle

Baby bottles should be cleaned using hot soapy water and a bottle brush before being sterilized and left to air dry.

Click to see bottle brushes on Amazon

Plastic bottles are amongst the hardest to clean because breast milk and formula tends to stick to them. Plastic also takes longer to air dry than other materials.

You can clean baby bottles in the dishwasher on a high setting, but plastic bottles may become stained, particularly if you include dishes with tomato-based sauces on them.

(Read more on dishwashers vs bottle sterilizers, and see what the CDC has to say about cleaning infant feeding items.)

Price of baby bottles

The cheapest plastic baby bottles cost as little as $1 each, whereas silicone, glass and stainless steel bottles can cost up to $40 each.

The average price of a standard baby bottle is around $6.

Baby bottles are usually sold in packs of three to six and come complete with the other bottle parts like the collars, nipples, covers and anti-colic vents.

Which baby bottle to choose?

Most parents choose plastic baby bottles because they’re the cheapest and most practical. BPA-free, PVC-free and phthalate-free bottles are thought to be less toxic, but all plastic comes with some level of risk.

Glass and stainless steel baby bottles are non-toxic and easy to clean, but the fear of dropping or shattering a glass bottle and not being able to see how much milk is in a metal bottle are deal breakers for many.

If you have the budget for it, baby bottles made from food grade silicone are a safe and practical choice.

You’ll probably need to buy these online though, as they can be harder to come by in your local grocery store.

2. Nipple

The nipple on your baby bottle has one of the biggest impacts on your baby’s experience.

With a few types of nipples to choose from, it’s important to consider your baby’s preference as well as age in finding the right fit.

As the nipple is the part of the bottle that goes into your baby’s mouth, it’s most important for ensuring that your baby is comfortable. Any issues with refusing a bottle, falling asleep at the bottle or choking on milk usually stem from using the wrong nipple.

Every baby is different and so the best baby bottle nipples are those that are the right shape, softness and flow rate for your baby’s needs.

Nipple materials

It’s easy to tell what a bottle nipple is made of by the color of it. Silicone nipples are clear, whereas latex nipples are an opaque yellow color.

  • Silicone: Most bottle nipples are made from silicone. These are hypoallergenic and durable enough to last around three months before they need replacing.
  • Latex: Some babies prefer these as they are softer and more similar to real human nipples. Latex nipples last for around two months but not as long for babies with teeth. Just be careful, because some babies are allergic to latex.

Nipple shapes

If your baby doesn’t take well to bottle feeding, the first thing to try should be a different-shaped nipple.

  • Traditional shape: Basic bell-shaped bottle nipples are the cheapest option and most widely available in stores.
  • Naturally-shaped: Wide nipples replicate the shape of a breast. This is useful when transitioning a baby from the breast to a bottle.
  • Orthodontic: These irregular-shaped nipples promote healthy teeth formation in babies who are teething.

Flow rates

It’s important to choose the right ‘level’ of nipple for your baby’s age.

Too slow and they’ll get bored or frustrated. Too fast and they will sputter and choke.

  • Slow flow nipples: Best for newborn babies, the hole in the nipple is small to only allow a very slow flow of milk. This prevents babies from choking on too much liquid at once.
  • Medium flow nipples: When babies are a few months old, you can use a medium-flow nipple with a larger hole to feed them more quickly.
  • Fast flow nipples: Fast-flow nipples have the largest hole and are made for older babies who can keep up with more milk at a time.
  • Variable: Variable-flow nipples have an X-shaped or Y-shaped hole. The harder the baby sucks, the faster the milk comes out.

Cleaning a bottle nipple

Just like baby bottles, nipples should be cleaned thoroughly in hot soapy water, rinsed, sterilized and left to air dry.

Both silicone and latex nipples can be cleaned in the dishwasher.

Price of bottle nipples

Baby bottle nipples cost between $2 and $5 each and generally come in packs of two to six.

You’ll often get some nipples included when you buy your bottles, but you’ll also need to buy extras for when they become worn out and damaged.

As your baby gets older, you may need to upgrade to a faster flow nipple, too.

Which to choose?

Not all nipples will fit on to all bottles, so it’s best to choose the same brand for both.

For babies that have no issues with bottle feeding, traditional silicone nipples are the best.

If you have any problems transitioning your baby from the breast to a bottle, then it’s worth trying naturally-shaped or latex nipples.

3. Collar

A baby bottle collar, also known as a screw ring, is a ring of plastic that screws on to the bottle.

It has a hole where the nipple pokes through.

When you buy baby bottles, they will come with collars.

If any of your collars get lost or break, you can buy replacements that fit your bottle size online or where you purchased your bottles in most cases.

Price of bottle collars

If you take good care of the bottle collars you may never have to buy any extras, and can rely on the ones that come with the bottles.

If you need replacements, they’re $1 to $2 each, depending on the brand.

Which to choose?

You should always use the collars that are made to fit the bottles that you have.

Another brand may appear to fit, but this will increase the chance of the bottle leaking.

4. Cover

Also known as a bottle cap or lid, the nipple cover attaches to the top of the bottle.

It keeps the nipple clean and means that you can put the bottle into your bag without it spilling.

Most (but not all) bottles come with nipple covers.

But, just like collars, they are easy to misplace so you may need to buy replacements.

If you do, you can get replacement bottle caps online for $1 to $2.

5. Anti-colic vent

Colic is a common condition that causes healthy babies cry for hours on end — typically, they cannot be calmed.

There can be many causes of colic, one of which is trapped wind, caused by swallowing air when feeding from a bottle.

To prevent air from bubbling into the milk and being swallowed, anti-colic bottles have an extra part—a vent—that lets air into the bottle while keeping it away from the nipple.

Types of anti-colic vents

In baby bottles that have separate parts for the vents, there are two main types:

  • Straw vents: This type of vent attaches between the bottle and the nipple. Air is drawn through slits in the nipple and passes through the milk via a straw.
  • Bottom vents: This type of vent attaches to the base of the bottle. It has vents to allow air into the bottle without it entering the milk

Bottles that don’t have separate vents have a hole in the side of the nipple that allows air in.

Air will bubble through the milk, but this can be minimized if you hold the bottle with the hole facing upwards.

Cleaning anti-colic vents

Bottle vents are the trickiest part of a baby bottle to clean.

You’ll need to use a special cleaning brush.

Click to see anti-colic vent brushes on Amazon

These usually come with anti-colic bottles, although can can also buy replacements if needed.

Price of bottles with anti-colic vents

Baby bottles with anti-colic vents are pricier than standard baby bottles, yet some parents swear by them.

If you have a baby who suffers from digestive discomfort, then the vented bottles are well worth the money.

Bottles with anti-colic vents cost around $5 to $8 each. If you lose any parts and need to replace the vents, you can get these for around $2 to $3 each.

Wrapping up

The simplest and cheapest baby bottles consist of a tall plastic bottle, a bell-shaped silicone nipple, and a plastic collar.

However, there are many more types of baby bottles to choose from which may be better-suited to your baby.

Specially-shaped bottles and nipples can be more comfortable for babies and anti-colic vents are useful to stop air bubbles from getting into the milk.

The more specialized the bottle is, the more expensive it will be. If you choose one of the more rare types of bottles, you might find it tricky to quickly access replacements parts.

Plus, the more bits and pieces a bottle has, the more work is required to clean it.

I’d recommend going for the tried and true baby bottles to begin with — we’ve always done well with Dr. Brown’s anti-colic bottles (Amazon link) — but if you hate cleaning a lot of small parts, you can start with a bottle that doesn’t have the extra vent.

Click to see on Amazon

If you have any struggles with bottle feeding, you can then consider alternative bottle shapes, nipples, and anti-colic vents which may be preferable for your little one.

Before you go, check out more guides like:

Hope this helps!