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.
One star only and that’s just because it is an ice colour. The product looked good but apart from that it was useless. Terrible weak coffee, no matter how many scoops of coffee put into filter. I returned the product as it simply did not make drinkable coffee.