Yeast propagation and pitching

The aim of yeast propagation is the multiplication of yeast in one or more propagation tanks under optimal growth conditions, accelerated by the supply of sterile air or oxygen.

The continuous or batch process is used in the brewing industry between pure cultivation and yeast pitching before fermentation.

The closed process control combined with the hygienic design of the plant enable maximum microbiological safety and prevent contaminations. The automatic operation of the propagation system achieves a consistently high yeast quality – a basic requirement for high beer quality.

We also offer suitable solutions for the storage of the harvest yeast and its treatment before reuse.

Advantages and functions

  • Provision of vital and active yeast in sufficient quantity for fermentation

  • Continuous or batch propagation in a single tank process or using several tanks

  • Closed process control protects against contaminations

  • Targeted temperature control and intensive sterile air input for fast propagation

  • Optional in-line oxygen and alcohol measurement

  • Hygienic design, full CIP capability

  • Easy operation, low maintenance effort, long service life

  • Fully automatic operation with standard PLC and touch panel

  • Optional integration in process control system and remote maintenance

  • Individually dimensioned and designed for each specific application

  • Equipment and components according to customer specification

  • Compact tubular-frame system (skid mounted)

Technical Description

The cylindroconical propagation tank is filled with sterile wort, which has been heat-treated and cooled in the upstream wort sterilizer. The yeast is then added under sterile conditions. Another proven option is to sterilize the wort through the heating jacket of the tank. The cooling system, which is also installed in the tank shell, enables precise temperature control and the yeast to be brought up to operating temperature. Adapted to the specific process control and capacity of the brewery, several propagation tanks of different sizes can also be connected in series.

In the propagation tanks, the yeast is intensively aerated with sterile air in order to achieve fast propagation and high vitality. This is done with an external mixing and aeration device in which the yeast is mixed with sterile air via the GDI gas injector developed by corosys. The injector divides the sterile air into very small bubbles and thus ensures intensive contact between air and yeast. The pumping over leads to a powerful mixing. An agitator in the tank can be avoided in favor of hygiene.

All components used, e.g. pumps, are designed in such a way that they cause as little mechanical stress on the yeast as possible and treat it gently.

The yeast propagation can be controlled by a PLC control with touch panel or by a superior process control system.

Designed for high hygienic standards, yeast propagation is suitable for all cleaning agents commonly used in the beverage industry. The injector is cleaned via an integrated bypass and the air line can be sterilized via an integrated steam supply line.

Technical Specifications

Heating media steam or hot water
Cooling media glycol