Introducing Water and an Open Cup to Your Baby

Starting solids brings a new question parents don't always think about in advance: when does water come in?

The short answer: at the same time as solid food — around 6 months. Here's everything you need to know.

When to introduce water

The NHS recommends offering small amounts of water with meals from around 6 months, when you start solid foods. Before this age, breast milk or formula provides all the fluid your baby needs.

Important: Under 6 months, giving water can actually be dangerous — it can interfere with milk intake and upset the balance of electrolytes in a very young baby.

From 6 months, water can be offered:

• With solid food meals
• Between feeds in warm weather
• Any time your baby seems thirsty

How much water does a baby need?

At 6–12 months, milk is still the main drink. Water is supplementary.

A few sips with each meal is plenty to begin with. There's no specific daily target — let your baby's thirst guide it. By 12 months, babies typically drink around 120–180ml (4–6oz) of water per day alongside their milk.

Not water, ever before 6 months. Not juice at any point — it's not needed and is harmful to developing teeth.

Open cup vs sippy cup: what the NHS says

The NHS specifically recommends using a free-flow cup (open cup or cup with a free-flow lid) rather than a sippy cup with a non-spill valve from the start.

Why?

• Sippy cups with valves require the same sucking motion as a bottle, which doesn't support the oral development that drinking from a proper cup does
• Free-flow cups help babies develop the lip, tongue, and jaw coordination needed for speech
• Cups support a natural drinking pattern

It's messier. That's fine.

How to introduce an open cup

1. Start with a small amount — a centimetre of water in the cup
2. Support their hands around the cup — you're controlling the tilt, they're learning the concept
3. Let them explore — mouthing the rim, tipping it, making a mess. That's how they learn
4. Use a weighted base or a small, light cup they can hold easily
5. Be consistent — offer the cup at every meal

Most babies manage a few sips by 6–7 months and are reasonably competent by 9–12 months.

Popular cups to try

• Doidy Cup — angled design, brilliant for teaching open cup drinking
• Munchkin 360° — free-flow all the way around the rim, less messy than fully open
• EZPZ Mini Cup — tiny weighted cup with a suction base
• A plain shot glass works beautifully if you're feeling minimal

Fluoride and tap water

UK tap water is safe for babies from 6 months. You don't need to boil water for babies over 6 months unless advised otherwise.

Fluoride in UK tap water is at levels considered safe and beneficial for developing teeth. No need for special filtered or bottled water.

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