Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Love the look and feel of the bottle and it's really easy to use. However the stainless steel sadly changes the taste of my matcha. My partner and I only used it a couple of times, and have now gone back to using a sieve and electric whisk.