Combine the soaked almonds and filtered water in a blender. Blend on high speed for 1 to 2 minutes, until the mixture appears creamy and smooth.
Place a nut milk bag or a fine mesh strainer lined with cheesecloth over a large bowl. Carefully pour the almond mixture into the bag or strainer. Gently squeeze or press to extract as much almond milk as possible.
Return the strained milk to the blender. Add maple syrup and vanilla extract if desired. Blend briefly to combine. Taste and adjust sweetness if necessary.
Transfer the almond milk to a sealed container and refrigerate. Shake well before each use as natural separation may occur. Enjoy within a week.