Can You Reheat Oatmeal?

Yes, you can reheat oatmeal, and it’s one of the easier leftovers to get right. The issue with cold oatmeal is that it sets into a thick, stiff block as it cools, because the starches absorb the remaining liquid. The fix is simple: add liquid before reheating, not after, and the oats loosen back up as they warm.

Can You Reheat Oatmeal?

Yes. Cooked oatmeal keeps well in the fridge for up to five days in a sealed container. It’s low-risk from a food safety standpoint, though like any cooked grain it should be refrigerated within two hours of cooking. When reheating, you’re looking for it to be hot throughout, around 75°C (165°F), and back to a loose, porridge-like consistency rather than the stiff block it becomes in the fridge.

The Most Important Step: Add Liquid First

Before you apply any heat at all, stir in a splash of liquid. The amount depends on how thick the oatmeal has become:

• For a standard portion: two to three tablespoons of water, milk, or plant-based milk per cup of cold oatmeal
• For very thick or overnight oats: up to a quarter cup, added gradually
• For flavoured oatmeal: use the same liquid you originally cooked it with for the most consistent result

Skipping this step and applying heat directly to cold, stiff oatmeal results in uneven heating and a gluey texture on the outside while the centre is still cold.

Reheating Oatmeal in the Microwave

The quickest method and the one most people use. Works well as long as you stir between bursts to distribute heat evenly.

1. Transfer the oatmeal to a microwave-safe bowl. Add two to three tablespoons of liquid and stir well.
2. Microwave on full power for 60 seconds.
3. Stir thoroughly. This is the key step: stirring moves hot spots to the edges and cold spots to the centre, giving you even heat on the next burst.
4. Microwave for another 30 seconds, stir again, and check. Repeat until evenly hot.
5. Add toppings after heating, not before.

Total time is usually 90 seconds to two minutes for a standard portion. Larger quantities take proportionally longer.

Reheating Oatmeal on the Stovetop

Takes a few more minutes but gives better control, especially if you want to adjust the consistency as you go.

1. Spoon the oatmeal into a small saucepan and add two to three tablespoons of liquid per portion.
2. Heat over medium-low heat, stirring continuously.
3. As the oats warm, they’ll loosen. If they’re still too thick, add another splash of liquid and stir it in.
4. Heat for three to four minutes until smooth and hot throughout.

The stovetop is particularly good if you’re reheating a large batch or adding fresh ingredients as it heats, like a banana or extra spices.

Can You Reheat Overnight Oats?

Yes, though overnight oats are typically eaten cold by design. If you prefer them warm, the microwave method works well: add a splash of your chosen milk, stir, and heat for 60 to 90 seconds at full power, stirring once halfway. The texture will be softer than hot-cooked oatmeal since the oats have been soaking all night.

Toppings: Before or After?

Always after. Fresh fruit, nuts, seeds, honey, and nut butters all change in texture or flavour when heated:

• Fresh berries: burst and release excess liquid if microwaved, turning the oatmeal watery
• Nuts and seeds: lose their crunch
• Honey or maple syrup: fine either way, but easier to control the sweetness if added after
• Nut butter: stir in after heating; it melts in from the residual heat

How Many Times Can You Reheat Oatmeal?

Two to three times is practical for plain oatmeal without toppings. Unlike meat or rice, plain oatmeal doesn’t carry a significant bacterial risk on repeated reheating. The limiting factor is texture: each reheating makes it slightly starchier and thicker, and the flavour becomes flatter. After three reheats, quality rather than safety is the reason to stop.

Which Method Should You Use?

Q: I have been reading all over the internet of ways to make oatmeal and eat on it through the week. One of the main points, they tend to neglect, however, is how to reheat it! What is the best method and is anything else required?

A: Reheating oatmeal is very simple, the two best ways to do so are either with your microwave or on the stove!

The Stove Top Method

Reheating your oats on the stove is as simple as scooping your desired amount into a pot, and adding a splash of water or milk to help loosen them. Simmer on medium low for seven minutes or until warmed all the way through.

The Microwave Method

When you want a quick yet filling breakfast, oatmeal is the best way to go, and being able to warm it up in your microwave makes it that much better. Just put your oatmeal into a microwave safe container, add milk or water, this will vary based on taste.

Mush the oatmeal to make a bowl in the center, this will help your oats heat all the way through faster. Cover and microwave for 45 seconds, stir, and microwave for another 45 seconds or until desired temperature is reached.

Oatmeal has always been a standby breakfast, and with new trends in how to create delicious, hearty meals out of it, oats are finally getting the spotlight they deserve. With quick and easy ways to reheat them, there is no reason you should not be getting your fill of oatmeal.