Breast Milk Smells Like Onions, Fish, Or Egg? (Know Why & What To Do)

Every mother’s breast milk is unique in taste and smell. This is mainly because of food, medications, storage techniques for pumped breast milk, and lipase. If stored correctly and still your breast milk smells funny, then it can be due to your diet, or apocrine glands present in the nipples, or the presence of high lipase in breast milk. No matter what your breast milk smells like, as long as it’s not spoiled, it’s safe for the baby to consume.

Dear Mama,

Do you have days when you just start stinking like onions or garlic even though you hadn’t had one in ages, plus you bathe every single day? Or every time you pump your milk, it smells so bad that you think your milk has gone bad and dispose of it?

Well, for starters, you’re not alone. Many moms around the globe have faced this either in their pregnancy or right after they’ve given birth.

If you don’t trust me, search the internet, you’ll find multiple forums where moms have ranted nonstop about how they smell or their milk smells like onions, fish, eggs, garlic, or even vinegar.

Human milk is unique in its taste, smell, and color, and these depend on what you eat, what medications you take, or how you store your milk (if stored incorrectly, your milk can smell rotten).

But, always remember that no matter what it smells or looks like, if it isn’t spoiled, then your breast milk, the ‘liquid gold, is the best food for your baby.

What affects the taste, smell or appearance of breast milk?

Have you ever noticed that your newborn, who doesn’t even open her eyes much, calms down instantly every time you pick her up or take her from someone else’s arms?

It’s because you put out a unique smell that your baby recognizes from when she was in your womb and gets the same feeling of warmth and comfort when you hold her close.

The amniotic fluid that nourishes your baby for 9 months has similarities in taste with your breast milk. So, babies find comfort even when they’re exposed even to the smell of your breast milk.

1. Diet and Medications

You might’ve heard the phrase ‘eat right because your baby’s going to get the most nutrition from your breast milk. Being true in it, the flavors of your breast milk does change from time to time depending on what you eat.

Your breast milk can take on a very subtle difference in its flavor, according to what you ate for dinner yesterday. This is one of the reasons why breastfed babies enjoy a huge variety of food flavors when compared to formula-fed babies.

Even certain medications you take can alter the taste of your breast milk. Talk to your doctor soon if your little one rejects your breast milk because of how your breast milk smells after taking those medications.

2. Storage techniques

How you store your milk in the fridge can also impact the appearance, smell, or taste.

If you keep it too long at room temperature, you might notice different layers appearing in the bottle. This doesn’t mean the milk has gone bad; the foremilk (breast milk rich in water) and hindmilk (breast milk rich in fat) are separated.

Slightly swirl the bottle to mix them up, and you can feed the milk to the baby. Make sure you don’t freeze or store your milk in the fridge, which was kept for more than an hour in the open. Also, your milk can get spoiled faster if kept in the open near any contaminants like meat because bacteria can be transferred.

The storage bags you use should be dry because wet storage bags can become ground for bacteria to grow. So, make sure you comply with all proper storage instructions when it comes to storing and freezing your ‘liquid gold.’

3. Lipase

Sometimes your breast milk can smell very unpleasant, like soapy or sour, because it contains a high amount of lipase.

Lipase is an enzyme that is normally present in breast milk and has many benefits, as it helps break down the fats so that your child receives fat-soluble nutrients and fatty acids through the milk.

Lipase activity increases in the milk kept for a longer time at room temperature or even in the fridge before being frozen. So milk with high amounts of lipase can smell soapy or even sour, but it doesn’t mean it’s harmful to your child.

If your child rejects the milk after her first taste or even later when she grows and starts having taste preferences, you can scald your fresh milk before you freeze it.

Scalding can help stop enzymes from breaking down the fat and prevent the milk from smelling differently.

Why does breast milk smell like onions?

This is a concern that many mothers have faced even though they don’t like onions or haven’t eaten one in weeks, and it still smells like onions, and it’s just not your breast milk that reeks of onions, but even you smell like a walking-talking-onion.

The reason breast milk smells like onions is because of the apocrine glands present in the nipples.

These are the same glands that are present in the armpit and groin area. These glands can cause an onion-like smell even when you sweat. It might be activated in some mothers due to the saliva of babies during nursing.

Because of these reasons, you can smell like onions, and your nipples can also smell and taste like onions every time you breastfeed. If you notice your little one rejecting your milk or your breasts, talk to your doctor immediately.

Why does breast milk smell like fish, eggs or garlic?

When your breast smell smells or even tastes slightly fishy, it can be due to many factors, like if you’ve consumed fish or take fish oil supplements. Try avoiding these and see if the smell or taste persists.

You might notice that sometimes breast milk, when frozen or refrigerated, smells like eggs. This is because of the high amount of lipase present in breast milk.

Although, this doesn’t mean your breast milk has spoiled, and you can prevent this if you feed your milk immediately after pumping or directly breastfeeding your baby.

Your breast milk can even smell of garlic and even vinegar, depending on your diet. If you have consumed lots of sugar-based food, your breast milk can smell of vinegar.

Also, if you happen to sweat a lot but don’t have regular baths- your unhealthy hygiene can cause your breast milk to smell like vinegar.

Always double-check with your doctor before making any major lifestyle changes that affect your or your baby’s health.


What foods make breast milk taste better?

There’s no particular food that will make your breast milk taste like a freshly made smoothie, but eat a balance of healthy foods like leafy vegetables, fruits, grains, proteins.

You can avoid, for some time, eating garlic, high amounts of sugar, onions, or dairy if you think your breast milk has started smelling differently.

Can babies drink cold milk?

If your baby is teething, you can relieve them by making popsicles from your breast milk and feed them.

Can I microwave baby’s milk after freezing?

Heating breast milk or formula in a microwave isn’t recommended because the microwave heats baby’s milk and formula unevenly, which can cause “hot spots” in milk to burn your baby’s mouth and throat.


Your breast milk will always be unique in its color, taste, and smell, which your baby will always seem to enjoy no matter what time of the day. So, don’t worry about your baby rejecting your breast milk because of a particular smell.

But, if your baby does happen to reject your milk or your breasts, try changing your diet for a week, and if you’re feeding pumped milk, then follow proper storage instructions and check if your baby still feels the same. If yes, then talk to your pediatrician about the same.

Meanwhile, comment down below about your journey of breastfeeding your little one so far.

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Located in India and a mother to a joyfully mischievous son, Kelin is the wife of the world’s most patient man and a busy homemaker. When she’s not busy cooking and running after her kid,  you can find her in a corner reading, or penning down words on her laptop. She believes the world will always try to instil ‘mom guilt’ in new mothers, but she goes by the maxim ‘a mother knows best'.

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