
Dec 31, 2021
This post may contain affiliate links. Please read our disclosure policy.
“What’s the best mason jar for overnight oats?”
This is a question I’ve been asked many times since I’ve shared a lot of overnight oats recipes on my website, and each time I answer it I think “I should just write a post and explain which ones work best!”
Below, you’ll find various container options and tips for storing overnight oats, so they stay fresh.

Making overnight oats the night before is a smart way to plan ahead and have a delicious, hearty breakfast ready for you to grab the next morning. Whether you like to prep yours in a glass jar or plastic container, there’s something for you.
Best Jars for Overnight Oats
The best jar and container for overnight oats should have:
- Wide opening
- Leak-proof lid
- Microwave-safe
- Freezer-friendly
The options I’ve provided below, check off all the boxes and make your breakfast look cute will doing so. I filmed a quick video so you can see each of the jars in action!
8-ounce Wide Mouth Mason Jars

If you prefer glass, this will be a favorite option for overnight oats that’s microwave-safe and leak-proof.
Note: I used these taller 8oz mason jars in the photo at the top of this post. But if I had to choose a favorite, I’d go with the wide-mouth version as the best for single-serve mason jars. It is so much easier to stir in toppings when you have a wide-mouth jar.
10-Ounce Overnight Oats Jars with a Spoon

These gorgeous jars come complete with a spoon that attaches to the jar, so you can take them on the go!
8-ounce Oat & Yogurt Jars

A trendy-looking glass jar option with black lids that screw on and keep spills at bay.
8-ounce Freezer Jars

A freezer-friendly option made with food-grade plastic and leak-proof lids.
32-ounce Locking Lid Food Storage

If you want to batch prep oats, this is the container. It holds up to 4 servings and can be frozen.
What Size Jar for Overnight Oats
You want a jar that gives plenty of room for a hearty portion of oats and mix-in’s, so anything from 8 to 16 ounces is ideal for a single-serve jar.
Keep in mind, jars with a wide openings also make it easier to prep and eat the oats.
Where to Find Mason Jars for Overnight Oats
You can find mason jars and other containers for overnight oats on Amazon, as well as our usual shopping spots like Target and Walmart. I’ve found that Amazon is convenient but in-store purchases for glass jars tend to cost less.
How Long do Overnight Oats Last
Most overnight oats recipes will up to 5 days in the refrigerator, and for this reason, as well as their delicious, creamy texture, they are a breakfast phenomenon I like to prep ahead at the beginning of the week.
The one exception would be an overnight oats recipe with banana, like my Banana Overnight Oats. While these taste like a dessert for breakfast, the bananas get a little too mushy after 3 days, which isn’t often a problem since they usually disappear by day 2.
Can You Freeze Overnight Oats
Overnight oats are a freezer-friendly recipe that will last up to 3 months. However, there are a few tips to freezing oats, so they thaw out tasting like you made them the night before:
Add mix-in’s after the overnight oats are thawed
You want to freeze the overnight oat base as plain as possible. Items like fruit, nuts, and seeds get mushy in the freezer and affect the overall texture.
Don’t fill the jar all the way
If you plan on prepping and freezing a batch of oats, use the freezer-safe plastic containers and don’t fill them all the way. When frozen, contents expand and can cause the container to bust. A ½-inch from the lid should be the stopping point.
Ratio for Overnight Oats in a Mason Jar
I’ve got the ratio of oats to liquid for overnight oats down to a science. Below is my base recipe that’s fail-proof, and you can make all your own by adding different fruit, seeds, and nuts. Here’s what you’ll need for each serving:
- ½ cup old-fashioned oats
- ½ teaspoon ground flaxseed
- ¾ cup milk
- ¼ teaspoon vanilla extract
- ½ cup chopped fruit

Mason Jar Overnight Oats
Ingredients
- 2 cups old fashioned oats
- 2 teaspoons ground flaxseed
- 3 cups milk your choice
- 1 teaspoon vanilla extract
- 2 cups chopped fruit of your choice
Instructions
- Place four jars on a flat surface. Fill each jar with ½ cup oats, ½ teaspoon ground flax, ¾ cup milk, and ½ teaspoon vanilla. Stir to combine. Top with strawberries and refrigerate.
- In the morning, stir to combine. Warm up if desired or enjoy cold.
catherine
I’ve become obsessed with overnight oats lately and I was looking for the best jars to use. thanks for all these ideas, ordering now!