Measure the frozen berries and kefir before blending. Peel the banana and slice it into smaller pieces to help the blender process the ingredients smoothly. If using fresh berries instead of frozen, chill them beforehand for a colder smoothie.

Pour the kefir into the blender first. Then add the frozen mixed berries, banana slices, almond butter, and vanilla extract. Placing liquids at the bottom allows the blender blades to move more easily and blend frozen fruit efficiently.

Blend on high speed for about 45–60 seconds until the smoothie becomes creamy and evenly blended. If you prefer a thicker, colder smoothie, add ice cubes and blend again briefly.

Pour the smoothie into a tall glass or divide it between two smaller glasses. Garnish with fresh berries or a sprinkle of chia seeds if desired. Serve immediately while chilled and creamy.