Can You Heat Overnight Oats?

Should you heat overnight oats?

You can, but we do not recommend it. Here is why we recommend eating them cold.

• They are made to be eaten cold. The night in the fridge softens the oats, so there is nothing left to cook. Stir and eat, straight from the jar.
• Warmed, they are much like porridge. They turn creamier, more like a bowl of porridge than overnight oats.
• It adds a step and more washing up. The OATOLOGY jar is not microwave safe, so the oats go into a bowl or a pan first, and that is one more thing to wash.
• Some add-ins do not like heat. Yoghurt can split, fresh fruit turns mushy and protein powder can curdle, so most extras go on after warming.

Can you eat overnight oats warm?

Yes, if you prefer them warm. Make them as usual first, as in our basic overnight oats recipe: milk to the line (150ml), then one slightly heaped lid of rolled oats (about 50g) and 1 tbsp chia. Stir, seal and chill overnight. In the morning, tip them into a microwave-safe bowl or a small pan and warm them gently. Never put the OATOLOGY jar in the microwave.

The soak still happens overnight in the fridge, and it is what softens the oats. Warming changes the texture: they turn creamier, more like a bowl of porridge. They can also thicken as they warm, so loosen them with a splash of milk, the same fix our overnight oats ratio guide gives for a jar that is too thick.

Is there any benefit to heating overnight oats?

Not much. Compared with eating them cold, warming only changes the texture: they turn creamier, more like porridge.

Compared with making porridge from dry oats, soaking first saves a minute or two. Soaked oats only need warming through, about 1 to 2 minutes in the microwave, where UK porridge oat packs give about 2 to 4 minutes for a bowl made from dry. Oat brands also say an overnight soak gives creamier porridge.

So if you want a hot breakfast, porridge made the usual way takes only a little longer. Overnight oats are at their best cold.

How do you heat overnight oats in the microwave?

Warm them in a bowl, in short rounds, with a stir in between. Never put the OATOLOGY jar in the microwave.

• Tip them into a roomy bowl. Use a microwave-safe bowl big enough to let them bubble up. Oats can bubble over in a microwave.
• Warm in rounds of about 30 seconds. Use a low or medium power setting. Stir between rounds and check the middle.
• Stop when they are warm right through. That is usually about 1 to 2 minutes in all, going by UK oat and dairy brands' own instructions. Microwaves vary, so go by the oats, not the clock.
• Loosen and eat. Stir in a splash of milk if they have thickened, then eat straight away.

Why stir and check the middle? Microwaves heat unevenly. The Food Standards Agency says microwaved food can be very hot at the edges and still cold in the centre.

How do you warm overnight oats on the hob?

Tip the oats into a small pan. Warm them on a low heat for about 3 to 5 minutes, stirring often so they warm evenly. High heat dries them out or makes them catch on the bottom.

Take the pan off the heat once they are warm right through. Stir in a splash of milk if they have thickened, then tip them into a bowl and eat straight away.

Can you microwave overnight oats in a glass jar?

Not in ours. The OATOLOGY overnight oats jar is not microwave safe, and it is not a hot-food container. Warm the oats in a bowl or a pan, and eat them from a bowl.

Glass alone does not make a container microwave safe. Only put a container in the microwave if it is clearly marked microwave safe.

• The OATOLOGY jar is not microwave safe. Never put the OATOLOGY jar in the microwave, with or without its lids.
• The steel lid is metal. Metal should never go in a microwave. It reflects the microwaves, and thin metal can spark.
• A sealed lid traps steam. Sealed containers and tight lids trap steam, and they can burst in a microwave.
• No boiling water or hot milk either. Sudden changes in temperature can crack glass, so never pour boiling water or hot milk into the jar.

Taking them to work? Take the jar straight from the fridge with its sealing lid on, and put it in a fridge as soon as you arrive: milky food should not sit out for more than about 2 hours. When you are ready to eat, tip the oats into a microwave-safe bowl.

Can you heat overnight oats with yoghurt, chia or protein powder?

Yes, with a little care. Warm the oats first, then add most extras.

Yoghurt or protein powder already stirred in the night before? Tip the oats into a microwave-safe bowl or a small pan, warm them gently on a low setting or a low heat, and stop as soon as they are warm. Never put the OATOLOGY jar in the microwave. Powder warmed in the oats can still curdle. For protein jars, see our overnight oats protein guide.

How do you warm overnight oats safely?

Keep the jar in the fridge, at 5°C or below, until you are ready to eat. Milky food should not sit at room temperature for more than about 2 hours.

Warm only what you will eat, and eat it straight away.

How long a jar keeps depends on what is in it. Our guide to how long overnight oats last goes day by day.

Frozen a batch in a freezer container? Thaw it overnight in the fridge first, stir well, then tip it into a microwave-safe bowl or a small pan to warm.

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