Overnight oats, the basic ratio and five ways to flavour it

Overnight oats are rolled oats soaked in milk and yoghurt in the fridge for at least six hours, so they soften into a thick, creamy, cold porridge without any cooking. The basic ratio is one part oats to one part milk and half a part yoghurt by volume. Stir it together in a jar at night and breakfast is ready when you open the fridge.

The idea is not new. In the early 1900s the Swiss doctor Maximilian Bircher-Benner served his patients raw oats soaked in water with grated apple, lemon and nuts: the dish now known as Bircher muesli. Overnight oats are a looser, more flexible version of the same thing, made in a jar and flavoured however you like.

How to make it

1. Put the oats, milk, yoghurt, chia seeds, sweetener and salt in a jar or a bowl with a lid.
2. Stir well, making sure no dry oats are left at the bottom.
3. Close the lid and put it in the fridge for at least 6 hours, or overnight.
4. In the morning, stir again. Add a splash of milk if it is thicker than you like.
5. Top with fruit, nuts or seeds and eat cold, or warm it for a minute in the microwave.

The ratio

Measuring by volume is the easiest way to remember it, and it scales to any jar.

Without yoghurt, use one and a half parts milk instead. With chia, add an extra splash of milk, because the seeds absorb liquid as well.

Five ways to flavour it

Each of these goes into the base recipe the night before, with toppings added in the morning.

• Banana and peanut butter: mash half a banana into the jar with a spoonful of peanut butter. Top with the other half, sliced.
• Apple and cinnamon: grate half an apple straight into the jar and add 1/4 teaspoon of cinnamon. This is the closest to the original Bircher muesli. Top with chopped walnuts.
• Berry: stir in a handful of frozen raspberries or blueberries. They thaw overnight and turn the oats pink or purple. Top with fresh berries.
• Cocoa and cherry: add a teaspoon of cocoa powder and a few frozen cherries. Top with a little grated dark chocolate.
• Mango and coconut: use coconut milk or half coconut milk and add a spoon of desiccated coconut. Top with diced mango and lime zest.

Tips for the best texture

• Use rolled oats. Jumbo or ordinary rolled oats both work. Quick oats turn mushy, and steel-cut oats stay too hard without cooking.
• Add a pinch of salt. It sounds odd in a sweet breakfast, but it brings out the flavour of the oats.
• Add crunchy toppings in the morning. Nuts, seeds and granola go soft if they sit in the jar overnight.
• Use a wide jar. It is easier to stir and to eat from. A clean 350 to 500 ml jam jar is ideal.
• Thick yoghurt means thick oats. Greek-style yoghurt gives a dense, almost cheesecake-like texture; runny yoghurt or extra milk makes it looser.

Make ahead and storage

Overnight oats keep well in the fridge for up to three days, which makes them useful for preparing several breakfasts at once. The oats keep softening, so day three will be creamier than day one. Fresh fruit such as banana and apple is best added on the day, because it browns. Frozen berries and dried fruit hold up well.

Questions people ask

Are overnight oats healthy?

They can be a good breakfast. Oats are a source of fibre, including beta-glucan, a type of soluble fibre that research suggests may help lower cholesterol as part of a balanced diet. The NHS recommends adults aim for 30 g of fibre a day, and one jar of overnight oats with fruit gives a useful share of that. Our guide to fibre explains why it matters and easy ways to eat more. Keep the sweetener modest and let the fruit do most of the work.

Can I make them without dairy?

Yes. Use any plant milk and a plant-based yoghurt, or leave the yoghurt out and add extra milk. Homemade oat milk works well and keeps the flavour oaty. Soy milk and soy yoghurt add the most protein.

How do I add more protein?

Use Greek-style or skyr yoghurt, soy milk, a spoonful of nut butter or a spoon of chia or hemp seeds. Our high-protein breakfast ideas has more ways to build a breakfast that keeps you full.

If you like the jar-in-the-fridge habit, try chia pudding next. It works the same way.

Photograph: AI-generated image

Filed under oats, breakfast, meal prep, fibre.