Bronkhorst
Application note A001-FP04

Ice cream aeration

Ice cream is made by freezing and simultaneously blending air into a liquid mixture which contains fat, sugar, milk solids, an emulsifying agent, flavouring and sometimes colouring agents. For ice cream production the aeration process is crucial.

The air content in ice cream (often called overrun) affects the taste, texture and appearance of the finished product. Higher aeration will produce a tastier and smoother ice cream. Thus, for attaining an optimal structure of the ice cream, production machines must possess an accurate air flow controller that is able to deliver the amount of air necessary to maintain the ratio between cream and air constant, as a function of the cream flow

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Application requirements

The air mass flow controller must be assembled as a slave of the cream flow controller, therefore, some continuous mixers manufactures require instruments having analogue, while others require bus (digital) communication features (both available). Combined with the instrument’s high performance, this setup will enable a continuous and stable air flow against the required backpressure of the mixer. Due to the existing regulation, equipment users also require qualified filter systems.

Important topics

  • Constant cream aeration
  • Precise dosing
  • Reproducibility
  • Stable control


Process solution

Whipping ice cream into shape. To guarantee the right consistency and structure which ensure a full flavoured ice cream, the ice cream must contain the correct proportion and composition of air bubbles. Hence continuous aeration mixer manufacturers use a mass flow controller to dose an exact amount of air into the cooled mixer. Such mass flow controller (slave) will ensure a continuous air delivery, proportional to the cream flow (master). The mass flow controller must be capable of maintaining its performance regardless of any possible back pressure variation. Occasionally, a check valve is mounted at the mass flow controller’s downstream. If inlet pressure drops, such valve will avoid ice back stream into the instrument. A pressure meter is also used with the purpose of monitoring the inlet pressure.

The SEM picture below shows the ice cream microstructure. Air bubbles are a critical ingredient. Experts claim its optimal size, distribution and quantity are one of the secrets for having a creamy texture recipe. Hence, according to meet such demands, Bronkhorst has provided efficient solutions for enhancing continuous aeration processes.

Flow scheme
Flow scheme

SEM
Continuous aeration mixer