At 9 months old, your baby needs only three drinks: breast milk or formula as the primary beverage, and small amounts of water. That’s the complete list. Everything else, from juice to cow’s milk to herbal teas, is either unnecessary or actively harmful at this age.
Breast Milk and Formula Come First
Breast milk or formula remains your baby’s most important source of nutrition at 9 months, even though solid foods are now a regular part of the day. Formula-fed babies typically need around 600 ml (about 20 ounces) per day, though this varies as they eat more solids. Breastfed babies naturally adjust their intake based on how much food they’re eating at meals.
At this age, your baby is likely eating two or three small meals of solid food daily. Those meals are complementary, meaning they add to milk feeds rather than replace them. The balance gradually shifts over the coming months, but at 9 months, milk still provides the majority of calories, fat, and key nutrients your baby needs for brain development and growth.
How Much Water Is Safe
Between 6 and 12 months, babies can have 4 to 8 ounces of water per day. That’s a small amount, roughly half a cup to one cup total spread throughout the day. Offer sips of water from an open cup or straw cup during meals. It helps your baby practice drinking, gets them used to the taste of plain water, and supports digestion as they eat more solids.
You don’t need to push water at this age. Your baby gets plenty of fluid from breast milk or formula. The water is supplemental, not essential, and too much can actually be dangerous. Infants who drink excessive amounts of water can develop a condition called water intoxication, where sodium levels in the blood drop rapidly. Symptoms include unusual irritability or sleepiness, swelling, low body temperature, and in severe cases, seizures. Sticking to the 4 to 8 ounce range keeps your baby well within safe limits.
Why Cow’s Milk Should Wait Until 12 Months
Cow’s milk is the most common dietary cause of iron deficiency in infants. It’s low in iron, it can irritate the lining of a baby’s gut (causing tiny amounts of blood loss), and its high calcium and protein content interferes with iron absorption from other foods. Iron deficiency anemia during the first year of life can affect brain development, so this isn’t a minor concern.
A small amount of cow’s milk cooked into food, like in a sauce or mixed into porridge, is fine. The issue is using it as a drink to replace breast milk or formula before your baby turns one.
Why Juice Isn’t Recommended
The American Academy of Pediatrics recommends no fruit juice for babies under 12 months. Juice offers no nutritional benefit that your baby can’t get from actual fruit. It does, however, increase the risk of tooth decay and can train your baby’s palate to prefer sweeter flavors over plain water. Even 100% fruit juice with no added sugar carries these risks, because the natural sugars in juice are concentrated and stripped of the fiber that makes whole fruit a better option.
Once your baby turns one, small amounts of juice become acceptable, but at 9 months, it’s simply not worth introducing.
Plant-Based Milks Are Not a Substitute
Almond milk, oat milk, rice milk, coconut milk, and other plant-based drinks should not replace breast milk or formula for a 9-month-old. These beverages are nutritionally incomplete for infants. They’re lower in protein, fat, and several essential amino acids compared to breast milk, formula, or even cow’s milk. The nutrients they do contain are often harder for a baby’s body to absorb because of compounds like phytates that interfere with absorption.
Cases of malnutrition and micronutrient deficiencies have been reported in infants fed plant-based drinks as a primary milk source. Some carry specific risks: almond milk has been linked to kidney stones in infants, and certain rice milks contain concerning levels of arsenic. If your family avoids dairy for allergy or dietary reasons, talk to your pediatrician about a suitable formula rather than substituting with a plant-based drink.
Herbal Teas and Other Drinks to Avoid
About 9% of U.S. infants are given herbal teas or botanical preparations, most commonly chamomile, gripe water, or similar products meant to soothe fussiness or aid digestion. This practice carries real risks. Infants have small body weight and immature digestive, nervous, and immune systems, which means they respond to herbal compounds very differently than adults do.
Children have developed seizures from herbal teas, liver damage from dietary supplements, and lead or mercury poisoning from traditional remedies. In one documented case, a child was hospitalized after drinking about 4 ounces of tea made from home-grown mint leaves that turned out to contain a toxic oil. Even chamomile, which many parents consider gentle, can trigger allergic reactions in babies sensitive to plants in the chrysanthemum family. Herbal teas can also be contaminated with heavy metals or bacteria regardless of how “natural” they appear.
Sugary drinks, sodas, caffeinated beverages, and flavored waters are also off the list. None of these belong in a baby’s diet at any point during the first year.
What Cup to Use
Nine months is a great time to practice with an open cup or a straw cup during meals. You hold the open cup and help your baby take small sips. Expect mess. The goal isn’t perfect drinking skills; it’s building familiarity so that by 12 months, when your baby transitions off bottles, cup drinking feels natural. Sippy cups with spill-proof valves are convenient but don’t teach the same oral motor skills as open or straw cups, so use them sparingly if at all.
Offer water in the cup at mealtimes and breast milk or formula however your baby normally feeds, whether that’s nursing, a bottle, or increasingly from a cup as well. By keeping the drink options simple, you’re setting up healthy habits that carry well past the first birthday.