Why Are Dr Browns Bottles Leaking? What Are The Solutions?

You are using some Dr Browns bottles but discovered that there were occasional leaks of milk while breastfeeding.

Why did this happen? What are the solutions of Dr Browns bottles leaking? Let’s dig in to get more details.

Why Are Dr Browns Bottles Leaking?

Dr Browns Bottles Leaking

Vent system problems, overflow filling, improper nipple, and undried bottles are common causes of milk leaking out of bottles.

Besides, if you blend the milk or heat the bottle with the vent system inside, the bottle may leak also.

Vent System Problem

Dr Browns bottles are designed with a vent system, including the vent tube, the nipple, and the collar.

These components are combined to transport air to the back of the bottle. As a result, babies will not have regurgitation, or belching, thereby reducing fussiness.

However, these parts are removable, so they may not be installed properly, resulting in milk leakage.

Sometimes, the mother installs the bottle hastily, without tightening the collar, resulting in Dr Browns leaking.

In addition, parts such as nipples can be defective. They can be cracked or torn during the manufacturing process.

Heated The Bottle With The Vent System Inside

One of the mistakes moms make when reheating the formula is leaving the bottle’s vent system while heating.

Instead of taking this system out of the bottle and heating the milk, they heat the whole bottle to save time.

However, if the temperature of the formula is too high, milk will overflow into the ventilation system, resulting in milk leakage.

In particular, when mothers warm up the milk in the microwave, the milk will overflow into the vent more easily.

Therefore, moms should warm the milk first, put the vent system in the bottle, and then feed their babies.

Blend The Formula With The Ventilation System

For normal milk bottles, we usually mix water and powdered milk into the bottle and shake them well. Therefore, many think it is normal to dot it with Dr Browns bottles.

However, these bottles are designed with a ventilation system.

When the milk and water mixture is shaken without removing the system, the mixture can become clogged in the vent, making babies spit out the milk while being bottle fed.

Although it does not always happen, mothers should blend the mixture before placing the vent to ensure a smooth breastfeeding process.

Filling Problem

The filling issue is one of the common causes of milk leakage. Sometimes, people will mess up the milking process by adding water before adding powder.

It will cause the flour-water mixture to overflow the fill line, causing the milk to spill out.

Usually, the Dr Brown bottles are designed with eight ounces maximum fill line. If this line is exceeded, the milk will overflow.

Many mothers choose to pour milk into two separate bottles to avoid exceeding the fill line. However, putting the powder into the bottle before adding the water is important.

It will help dissolve the powder and avoid crossing the fill line that may cause milk leaks.

Improper Nipple

The nipple features two small internal vent valves, the teat and nipple. The improper nipple can cause milk leakage because it makes it harder for the baby to suckle than usual.

If your babies can adapt to medium-sized nipples, using a smaller one will cause them to break the vent valves and another part, causing milk to leak.

Also, sometimes in a hurry, mothers will mistake the size of the nipple of one bottle for another one. The milk will spill out because the bottle and the nipple are not compatible.

The Bottle Is Not Dry

If any part of the bottle is not dry, it will not allow the airflow to be evenly distributed in the bottle. Babies, when suckling, will swallow the air.

Sometimes, you need to keep the air out of the bottle to avoid choking and bloating.

It also may cause Dr Brown’s bottles leaking. Although it rarely happens, you should let the whole bottle dry on the bottle rack to avoid bacteria remaining in the bottle.

How To Fix Dr Brown Bottles Leaking?

How To Fix Dr Brown Bottles Leaking?

Replace The Vent System

Replacing the vent system of the bottle is essential once it is cracked. In addition, other parts of the tank should also be replaced every 6 months.

After a period of use, the bottles exposed to high temperatures often may crack.

Replacing them will ensure the quality of the bottle, preventing bacteria from sticking to the bottle over time. It both avoids milk leakage and ensures milk quality for your babies.

If you want to replace each part separately, you need to find the ones compatible with the other parts of the tank. Carefully check the type and information of these parts to avoid Dr Brown leaking.

Use Appropriate Nipple

Choosing the bottle nipple size should also be taken into account. As children grow older, the size of the nipple is also larger. Larger nipples allow the flow of feeding faster.

When your baby is getting older and you still give them a slow flow nipple, they may find it difficult while being fed. Therefore, you need to use a nipple that is the right size for your baby.

Normally, nipples with a slow flow of milk are used for babies from 0-3 months.

Babies from 4 to 6 months are suitable for nipples with the medium flow, while fast flow nipple is used for babies from 6 months to 1 year old.

Frequently Change The Nipple

Experts recommend investing in bottle nipples every two to three months, especially when there are scratches and lacerations on the nipple.

Most babies will grind, bite, or even chew on the nipple during bottle feeding. Therefore, it is inevitable that the nipples are torn.

Besides, the nipple is a difficult part to clean, so it is hard to avoid bacteria sticking. Nipple replacement helps limit bacteria exposure to babies and keeps the bottle milk nutrients during feeding.

Besides, you need to choose nipples of the same type as your bottle to avoid Dr Browns bottle leaking.

Control The Milk Temperature

The temperature in the bottle is too high, which will cause the milk to leak out due to the high internal flow pressure.

Warming the bottle in the microwave also makes it easier for milk to spill into the vent system.

So while warming the milk, you need to open the bottle’s lid and take the vent system out. Once the milk is warm enough, place the bottle vessel inside and close the lid.

In addition, when blending the powder and hot water mixture, you should keep the vent system outside to prevent the mixture from getting clogged in the silicone valve.

It will keep Dr brown bottles leaking from the top at bay while the baby is fed.

Apply For Good Feeding Position

The best feeding position for babies is sitting them down. The bottle should be placed horizontally or tilted to one side.

The bottle at a 45-degree angle is the right position to prevent milk from entering the Brown valve.

It will reduce the gravity of the milk, and protect the baby from choking and leaking milk due to the milk flowing too fast. You can refer to some guides to bottle feeding to do it perfectly.

Besides, you need to install the bottle parts correctly. A loose collar or vent system will cause milk to leak out.

However, you should not screw them too tight, either. Temperatures in bottles that are too high can cause them to crack.


How To Handle If Milk Leaks In Diaper Bag?

Once your baby can hold his bottle, you must put the bottle in the diaper bag when outing, leading to a terrible possibility of leaking.

Milk leaking into the diaper bag stems from the Brown bottle not being tightened. When tilted, it will spill the milk. In addition, if milk is spilled into the bottle vent system, it will leak into the diaper bag.

To handle this problem, you need to put the traveling disc of the bottle into the nipple. You need to choose the right type and size for the baby bottle you are using.

This leak-proof part will help stop the milk from coming out. Also, if you are not breastfeeding, ensure the bottle is kept upright.

How To Assemble The Bottle Parts Correctly?

To have a perfect bottle for your baby, you can follow these steps:

  • Step 1: Fill the baby feeding bottle to the line you want, but not beyond the max line. If you need to make powdered milk, put the powder in the jar first and then pour the warm water in later to avoid spilling the milk.
  • Step 2: Insert the nipple into the bottle and heat the milk. You should adjust the temperature to suit the amount of milk you heat.
  • Step 3: Remove the nipple and place the vent system in, put the nipple back in place, and tighten the collar just right.

What Should I Do If I’ve Lost a Part Of The Bottle?

You can buy back any damaged parts at the store you bought the bottle from. Alternatively, you can order them in Dr Browns’ bottles.

You can see customer feedback in the comment section to weigh up the delivery service and issues related to the product you intend to buy.


Why are Dr Browns bottles leaking? Common causes are vent system problems, filling issues, improper nipples, and undried bottles. Also, blending the milk or heating the bottle with the vent system inside can be another cause.

You can refer to the above solutions to solve this leaking problem. See you in the next topics!

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