Coffee grinding machine configured to provide a dose of stratified ground coffee and associated method

A coffee grinding machine for grinding coffee beans and forming a dose of ground coffee in a filter basket with a bottom layer of ground coffee having a first mean particle size and an adjacent layer of ground coffee having a second mean particle size, comprising:

• grinding members for grinding coffee beans,
• an electric motor for causing rotation of at least one grinding member with respect to another grinding member,
• a weighing member for calculating mass of the dose of ground coffee, and
• a processor, comprising processor circuitry, configured to execute instructions to cause, during uninterrupted grinding of coffee beans for forming dose, a variation of rotation speed of said electric motor between a first speed and a second speed depending on a mass of a first portion of a coffee dose which was ground at said first speed,
• wherein either
• said second mean particle size is smaller than said first mean particle size and said first speed is greater than said second speed or
• said second mean particle size is greater than said first mean particle size and said first speed is lower than said second speed.