Baby Smells Like Vinegar Teething | 10 Causes

| Reviewed By Sarah Schulze, MSN, APRN, CPNP

Everyone says they love the smell of a new baby, which is strange because in reality, babies don’t often smell that great.

Why does my baby smell like vinegar during teething? When teething, babies tend to drool and chew on their hands a lot more. The saliva and milk in a baby’s drool can cause them to have an acidic, vinegar-like aroma. However, an acidic smell in your baby’s poop could be a sign of an allergy, food sensitivity, illness, or more serious conditions.  

There could be many different things contributing to the lingering vinegar smell on your baby. Some are normal and not a cause for concern while others may be an indication of something more serious.

Let’s take a look at some of the most common culprits of a vinegar smell and what they mean for babies and parents. 

Why Baby Smells Like Vinegar When Teething

The teething process can begin as early as four months of age and last until the age of three. There are many other developmental stages that occur during this time period that coincide with teething.

You may notice that your baby smells like vinegar while they are cutting teeth.

This could be due to the fact that they are teething and, therefore, drooling more, but it could also be happening for a variety of other reasons that are not necessarily related to teething. 

1. More Acid in Saliva

Your baby’s saliva may be slightly more acidic while teething in order to help the new teeth emerge through the gums.

As babies ingest more saliva, the acidity may cause looser, vinegar-smelling stools; however, there is not much evidence for this.

If your baby has loose stool or acidic-smelling diarrhea for several days in a row, it may be time to call your pediatrician to rule out any other underlying causes. 

2. Drool Drying on Clothing

Babies are constantly drooling, spitting up, or spilling things on their clothes that can make them smell quite disgusting.

Drool, which is usually a combination of saliva and milk, can create a pretty pungent vinegar smell when it dries on clothes. Try putting a fresh outfit on her and see if that resolves the problem. 

3. Drool Drying in Neck Folds

Babies drink a lot of milk, and therefore, their drool may have milk mixed in as well. Once milk sours, it takes on a vinegar-like smell.

Drool can get in the cracks and folds of your baby’s body and begin to fester as it sits. You may notice an unpleasant smell around your baby’s head and neck as you hug her. 

4. Stomach Acid

In the first few months of life, babies will spit up often. This usually begins even before a baby begins teething.

Their spit up will be a combination of milk and stomach acid. This is the most common culprit of a vinegar smell on a baby’s clothes or body. 

5. Acid Reflux in Babies

Occasional spit up is normal for infants as their digestive system is still not fully developed. 

If you notice that your baby is spitting up a lot, you may want to consult your pediatrician. Your baby may just have a mild case of reflux.

However, if she is spitting up excessively, not gaining weight appropriately, and is unusually fussy during and after feedings, she may have a condition known as GERD, which is caused when the esophageal sphincter doesn’t close completely and allows stomach acid to travel back through the esophagus. 

GERD can be harmful and requires immediate medical attention. 

6. Sudden Diet Change

Any time a new food is introduced to babies, it can cause a new reaction due to their underdeveloped digestive system.

If a baby is having a negative reaction to a new food, she may spit up more often or have acidic, loose stools. These can be indications of food sensitivities or allergies. 

7. Food Sensitivity

Your baby’s stool can tell you a lot about their overall health and how their digestive system is functioning.

If your baby has loose, acidic poop or vinegar-smelling diarrhea, it could be a sign that she is having trouble digesting her food and may have sensitivities or allergies to something she is eating.

Dairy, lactose, eggs, soy, and nuts are common culprits and are often difficult for babies to digest.

8. Drying Sweat

Sweat is a mix of mostly water and bacteria. When it dries, the bacteria does not leave a pleasant odor. If your baby’s hands, feet, or skinfolds smell like vinegar, it could simply be dried sweat that is causing the odor. 

9. Certain Medications

There is no scientific evidence that medications can cause your baby to smell like vinegar.

If your baby is taking antibiotics, there is a possibility that they are affecting her gut and may cause diarrhea or acidic-smelling stool; however, there are no direct correlations between medication and a vinegar smell. 

10. Certain Infections

If your baby’s poop has a strong acidic or vinegar smell, it could be a sign of a bacterial infection.

Other Instances When Baby May Smell Like Vinegar

A cute baby boy holding his nose closed.

A vinegar smell on your baby could be due to something as simple as dried sweat. However, it could also be an indication of illness or other underlying problems.

Let’s discuss when the vinegar smell is nothing to worry about and when it should be taken as a warning. 

Baby Poop Smells Like Vinegar

As babies begin eating more solid foods, their poop will become more solid and really start to smell. However, a baby’s poop should not have a frequent acidic smell like vinegar.

If you notice this smell along with loose stool or diarrhea, it could be an indication of a more serious problem. 

One possibility is that your baby’s digestive system is struggling to digest something she ate. Food sensitivities and allergies often cause acidic diarrhea or loose stools.

Monitor what your baby is eating and pay particular attention to how lactose, dairy, eggs, nuts, and soy affect her. Try eliminating one at a time from her diet to find what she is allergic to. 

If your baby has acidic diarrhea that is accompanied by a fever over 101 degrees, she could have an illness or bacterial infection. Seek medical attention quickly. 

Baby Sweat Smells Like Vinegar

Vinegar-smelling sweat is caused by bacteria on the skin. Your baby’s hands and feet may smell like vinegar due to increased sweating in those parts of their body. This smell usually goes away after their bath. 

If the smell is not resolved by the bath and you notice that your baby’s sweat has a pungent smell of vinegar, it could be a sign of diabetes, disease, or other medical conditions.

It would not hurt to bring it up to your pediatrician, especially if there are other symptoms or unusual behavior. 

Baby Pee Smells Like Vinegar

Foul-smelling urine is usually a sign of a bacterial infection such as a UTI or dehydration. If you notice your baby’s urine smells unusual or foul, contact your pediatrician. 

Baby Hands Smell Like Vinegar

They may be tiny and cute, but a baby’s hands can be the dirtiest and smelliest part of their body.

Babies’ hands are constantly exposed to dirt, sweat, and other things as they use them to move around — not to mention how often babies suck on their hands and fingers, covering them in saliva and milk.

All of this dirt and bacteria definitely contribute to smelly hands. 

Breastfed Baby Smells Like Vinegar

If your baby is breastfed and smells like vinegar, it is likely because she has dried milk on her face, neck, or clothes.

If your breastfed baby’s poop has a vinegar smell, it could be from a food sensitivity to something that the mother ate. 

Nutrient Malabsorption

Malabsorption is a condition in which a baby’s body has difficulty absorbing the nutrients in her food. This can result in chronic diarrhea, abdominal cramps, bloating and gas, weight loss, and a failure to thrive or stunted growth.

Depending on the cause, malabsorption is usually treatable. If you notice any of these signs occurring in excess in your baby, contact your pediatrician right away so that she can begin running tests for malabsorption. 

Gut Microflora Imbalance

There is more going on in your baby’s stomach than you realize! In her gut, there are trillions of helpful bacteria that have an impact on her overall health.

Her body needs the appropriate balance of these bacteria or gut flora in the stomach in order to function properly.

If the levels of friendly bacteria in the gut are reduced, a microbial imbalance is caused. Symptoms of this include: 

  • Diarrhea
  • Constipation
  • Low energy/fatigue & poor concentration
  • Low mood
  • Constant colds & flu
  • Bloating
  • Eczema and allergies
  • Asthma

Gut microbiomes, or the friendly bacteria living in your baby’s gut, are affected by many factors but primarily by diet.

If you notice that your baby has frequent diarrhea or acidic stools along with some of these other symptoms, you may want to learn more about baby gut health and adjust her diet accordingly. 

Rotavirus or Other Illness

Babies, especially those who are mobile, encounter trillions of germs on a daily basis, and their likelihood of picking up illnesses increases.

Rotavirus, a viral infection, is the most common cause of serious diarrhea in infants.

If your baby has persistent diarrhea that lasts more than a few days, especially if it is accompanied by a fever, seek medical attention right away to determine if an illness is the underlying cause. 

Bacterial Skin Infections

Sometimes, a bacterial skin infection can cause a vinegar-like aroma on the skin.

In particular, one bacterial skin infection caused by corynebacterium can cause sweat to smell like vinegar. This infection generally affects the feet, groin, and armpit areas. 

How To Get Rid of Vinegar Smell on Baby

If dried, sour milk or sweat are the culprits of your baby smelling like vinegar, there are simple things that you can do to treat the smell on your own. 

  • Try to keep her neck, hands, and feet as dry as possible. Wipe away drool and milk, and check neck folds often.
  • Change clothes often. 
  • Washcloth baths are a quick and effective way to clean your baby throughout the day before bathtime. 

How To Get Smell Out of Baby Clothes Naturally

There are few things more frustrating than doing tons of baby laundry only to have the smell of spit up and sour milk linger in their cute clothes.

Adding a little bit of distilled white vinegar and baking soda into your baby’s laundry works wonders when it comes to removing both smells and stains. 

Related Questions: 

Why Does My Baby Smell Like Maple Syrup?

Many parents have said that they have noticed their baby occasionally smells like maple syrup even though the baby did not eat maple syrup.

This could be a coincidence, but you should always bring this up to your child’s pediatrician as this is the main symptom of Maple Syrup Urine Disease (MSUD). 

MSUD is a rare, inherited amino acid disorder that affects the way the body breaks down certain amino acids found in protein. It is named for the sweet maple syrup smell of the urine in untreated babies.

Your child’s doctor will be better able to assess the situation to see if there is cause for concern or a simple explanation like the material of their clothing giving off a syrup smell. 

When Is Teething Pain the Worst?

No two babies have the same teething experience. It is unique to every baby. Some babies feel a lot of pain throughout the entire process while others seem unphased by their emerging teeth.

This can make it difficult to determine exactly when teething pain is at its worst. However, based on the size of the teeth, Stage 5 is likely to be the most painful as this is when the large molars emerge. 

During the other stages of teething, painful teething symptoms may seem to be worse the four days before the tooth emerges and can last until three days afterward.  


If you have a vinegar-smelling baby, know that you are not alone! Moms all over the world are trying to pinpoint the cause of this unpleasant baby perfume.

We hope you have pinpointed yours or at least have more ideas to investigate further.