An air inlet arrangement for an ice cream machine or yogurt machine includes an air-solution tube supported in a solution container which is adapted for storing a predetermined volume of solution at a predetermined fluid elevation, and an air nozzle. The air-solution tube has an elongated structure defining a top end, a bottom end, and a process channel between the top end and the bottom end, wherein the air-solution tube has a height greater than the fluid elevation of the solution container, wherein a volume of the air-solution tube is such that the air-solution tube is arranged to contain 80 g or less of the solution.