Follow these simple steps to assemble your delightful Berry Smoothie Jars:

1. Prepare the Oats (Optional but Recommended): For a smoother texture and easier digestion, you can soak the rolled oats. Combine the ½ cup rolled oats with about ½ cup of your chosen milk in a small bowl. Let it sit for at least 10-15 minutes, or even overnight in the fridge. This step isn’t strictly necessary if you have a high-powered blender, but it helps create a creamier consistency. If skipping this step, add the dry oats directly in the next step.
2. Blend the Smoothie: In a blender, combine the 1 ½ cups frozen mixed berries, 1 cup Greek yogurt, ½ to ¾ cup milk (start with less, add more if needed), 1 tablespoon chia seeds, soaked oats (if using, drain excess milk first) or dry oats, optional sweetener (1-2 tablespoons honey/maple syrup), and optional ½ teaspoon vanilla extract.
3. Achieve Desired Consistency: Blend on high speed until the mixture is completely smooth and creamy. If the smoothie is too thick, add a little more milk, one tablespoon at a time. If it’s too thin, add a few more frozen berries or another tablespoon of oats or chia seeds and blend again. Taste and adjust sweetness if necessary.
4. Prepare Your Jars: You’ll need two clean glass jars with lids, approximately 12-16 ounces (350-475 ml) each. Mason jars work perfectly.
5. Layer the Jars: This is where the “jar” magic happens! While you can simply pour the smoothie in, layering adds visual appeal and textural variety. Consider these layering options:
   • Option A (Simple): Pour the blended smoothie mixture directly into the jars, filling them about three-quarters full to leave room for toppings later.
   • Option B (Yogurt Layers): Spoon a layer of plain Greek yogurt (about 1-2 tablespoons) into the bottom of each jar. Carefully pour or spoon the smoothie mixture over the yogurt. You can add another thin layer of yogurt on top if desired.
   • Option C (Oat Layer): If you didn’t blend the oats in, you can create a base layer with the soaked oats (or even dry oats mixed with a little yogurt/milk). Pour the smoothie mixture over the oat base.
   • Option D (Fruit Layers): Place a few whole or sliced fresh berries at the bottom of the jar before adding the smoothie. You can also alternate layers of smoothie with thin layers of fresh berries or even a sprinkle of granola (though add granola just before serving to keep it crunchy).
6. Seal and Chill: Wipe the rims of the jars clean, then securely fasten the lids. Place the jars in the refrigerator to chill for at least 30 minutes to allow the flavors to meld and the chia seeds to further thicken the smoothie. For meal prep, they can be stored for longer (see FAQ).
7. Add Toppings (Before Serving): Just before you plan to eat your smoothie jar, remove the lid and add your favorite toppings. This prevents them from getting soggy. See the “How to Serve” section for ideas.