Mason Jar Overnight Oats
Published Jul 28, 2023•Updated Sep 23, 2024
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Simple and delicious with rolled oats, chia seeds, almond milk, and fruit, mason jar overnight oats are a healthy breakfast to make ahead and take on the go.
Meal prepping friends, I know you’re out there, and I have a great no-cook, make-ahead breakfast recipe to put on your list. When things get busy (looking at you back-to-school season), or we’re eating lots of meals out, I feel so much more balanced if I have a healthy breakfast prepped in the fridge. I make them parfait-style in mason jars with delicious layers, but there are so many ways to customize (see below).
Here’s how!
Ingredients
Before you get started, set out your ingredients.
- Rolled or “Old-Fashioned” Oats – Be sure to get rolled or “old-fashioned” oats. Quick cook oats, instant oats, or steel cut oats will work but won’t have the same texture.
- Nut Butter – Use any type of nut butter. I love natural almond butter or peanut butter.
- Chia Seeds – Chia seeds add texture and nutrition. You can skip these or stir flax seeds or hemp hearts or your other favorite healthy additions to the liquid and oat mixture.
- Liquid – Milk gives these a creamy texture – any dairy milk, oat milk, almond milk, or coconut milk are all great options.
- Honey – Optional, but adds a bit of sweetness on top.
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How to Make Mason Jar Overnight Oats
Step 1: Layer ingredients
Assemble the overnight oats in layers right in the mason jars. Almond butter on the bottom, then chia seeds, then oats.
Step 2: Pour liquid over top
Pour liquid over the ingredients. The liquid will soak through to the chia seed layer but shouldn’t affect the nut butter on the bottom.
Step 3: Top with fruit
Add fruit on top if you’d like. Fresh fruit is great, but frozen works really well (it will defrost by the time you eat them). For a little added sweetness, add a drizzle of honey on top.
Step 4: Refrigerate
Refrigerate, covered, for at least 8 hours and up to 5 days.
Variations on Overnight Oats
- Add yogurt – Adding yogurt to the oats gives them an extra creamy texture and adds protein. Plain or Greek yogurt, flavored yogurt, or non-dairy yogurt options all work well. For the best results, substitute yogurt for about 1/3 of the milk. Whisk them together before pouring over the oats.
- Add nuts or granola – Adding nuts or granola gives the oats more texture and protein. For the best results, add them on top right before serving so they don’t get soft.
- Add chocolate – Chocolate is always welcome in overnight oats! Stir some unsweetened cocoa powder and your sweetener of choice into the milk before pouring it over top. (Taste it to make sure it has your preferred amount of sweetness.)
Jars for Overnight Oats
- 8 ounce Mason Jars or 16 ounce Mason Jars – Either size will work. I make these in 8 oz mason jars and they are filled all the way to the top (as shown in photos above). If you make them in the 16 oz jars, you’ll have plenty of room to stir everything together before you eat it if you’d like. I also use these reusable lids (instead of the metal lids that come with the jars) because they are so easy to wash and store.
FAQs
You don’t need to, but giving them a little stir will help the oats to distribute more evenly in the liquid. If you assemble the jars in layers, you might want to stir everything together to combine it before serving.
Rolled (old-fashioned) oats are the most common in overnight oats and get an increasingly creamy texture the longer they soak. They will be soft and slightly chewy after 8 hours. Steel cut oats are small grains and need to soak longer in order to soften – about 24 hours.
Yes! Use sweetened almond milk or drizzle some honey, maple syrup, agave, or brown sugar in when you add the milk.
Your choice. Overnight oats can be eaten cold from the fridge, at room temperature, or warmed briefly in the microwave.
More Easy Oatmeal Recipes
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Mason Jar Overnight Oats
Equipment
- 8 ounce or 16 ounce Mason Jars
- Mixing Bowls
Ingredients
- 10 tablespoons almond butter (sub any nut butter)
- 5 teaspoons chia seeds (optional)
- 2 1/2 cups rolled or old-fashioned oats
- 2 1/2 cups milk (use any type of milk you like – skim, 2%, almond, oat, coconut, etc.)
- 10 ounces fruit, fresh or frozen
- honey (optional)
Instructions
- Set out five mason jars (I use 8 ounce but they are packed all the way to the top as in the photos; 16 ounce will give you more room to stir and add toppings; or use any other similar-sized container). Fill each jar with almond butter (2 Tablespoons / jar), chia seeds (1 teaspoon / jar), and oats (1/2 cup / jar).
- Slowly pour milk over top, giving it time to fill in the spaces between the oats. (Note: Be sure that the oats are just barely covered with milk. You may need a little more or less than the amount listed.)
- Top oats with frozen berries and a drizzle of honey (if using).
- Put lids on the jars and transfer to the fridge. Refrigerate overnight and up to five days.
- When you're ready to eat the oats, just pull them out of the fridge and dive in. You can stir everything together or eat the layers one at a time.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
I would not put the nut butter on the bottom of the jar again. It was very difficult to stir it well enough to incorporate through the oat mixture later, especially if you’re eating it cold. Next time, I think I will layer the nut butter after oats & fluid, before the fruit. Other than that, very tasty.
Is there an alternative to Mason jars? I’ve read that I can use the lids only once.
I should have mentioned this in the post, but you can use absolutely any container. Sometimes I just make a big batch of it in a glass Pyrex container or bowl. I use the reusable mason jar lids (linked in the post under “Jars for Overnight Oats”) that you can wash and use over and over. There’s a good video here – https://www.instagram.com/reel/CvP-ZsrNqsf/
I made a batch of these for my husband with peanut butter, and used a cinnamon roll flavored protein shake for the liquid and he said they were delicious! And very filling! He normally takes instant oatmeal to work and is hungry just a few hours later. These did the trick! And I love that I can switch it up for him. Thank you for the tips!
You’re so welcome! I’m so glad you found it helpful!
Can we also add flax seeds?
Absolutely! It’s great with added flax seeds. No need to adjust the recipe. Whole flax seeds won’t throw off the liquid amounts.
I am usually the person who makes 19 changes to a recipe before I try it, but since I’ve never had overnight oats before I followed your recipe exactly. OH MY GOODNESS it is sooooo good. I just had my first jar and now I can’t wait for tomorrow!!!