Liquid yeast: which benefits for the baker?

Liquid yeast – an opportunity for the baking industry

Liquid yeast provides a concrete opportunity for bakers to optimise production in industrial baking. It offers many technical and economical advantages. The liquid format makes highly precise, automatic dosing particularly easy and enables better control over the quantities used. Moreover, reduced handling on the part of operators and mixers also improves productivity.

Here are some of the many advantages of liquid yeast:

• quality: total control over fermentation characteristics
• practicality: easy mixing
• technical and economical feasibility: accuracy and consistency in dosing
• health: temperature maintained through to dosing
• hygiene: less handling
• environment: reduction in paper/cardboard packaging

The different types of liquid yeast

Yeast is in a naturally liquid state when it emerges from the fermenter. The yeast cream becomes solid only after having been partly dehydrated and compressed to be subsequently packaged. In order to facilitate delivery and use, liquid yeast can be supplied in three forms.

Liquid yeast in bulk

Liquid yeast is delivered in bulk in tankers, inside which the product flows freely in a continual loop in order to prevent any stagnation in the process. The consistency of the product is maintained by agitating the deposits at the bottom of the tanks. The tanks must be kept clean and therefore an In-situ Cleaning system can be implemented to remove the tanks and thus facilitate separate cleaning, while the adjacent tank is still in use.

Supervision and automation systems can be adapted to bakeries’ needs. A custom installation can therefore be automated in part or in whole. For Lesaffre yeast, for example, the accuracy of the liquid yeast dosages is guaranteed by the use of process equipment and instrumentation adapted to the type of production (electromagnetic flowmeter, quick-closing valve, electric totalizer and counter, flow detector, etc…).

Stabilised liquid yeast

Lesaffre’s stabilized liquid yeast is a patented invention that can be kept for several weeks without agitation and therefore packaged in containers. The containers must be stocked in a refrigerated zone. When the site of application is relatively far away, the liquid is kept flowing in a loop to avoid any yeast residue accumulating in any dead corners outside the refrigerated zone.

Yeast in suspension

The principle of yeast in a suspension involves incorporating the crumbling the yeast into water in situ. This necessitates the use of at least two tanks: one for diluting the yeast and the other for storing the product thus implemented.

Use of liquid yeast: Lesaffre quality approach

“Liquid yeast is more than a product, it’s a concept”explains Etienne MAILLARD, quality manager for the Lesaffre Group. Transportation, cleaning of tanks, compliance with safety standards … For Lesaffre, the task is to provide a global solution covering the product, the relevant installation and operating methods.

The product must be efficient and safe. The Lesaffre quality approach covers the rigorous selection of raw ingredients, compliance with Good Manufacturing Practices (GMP) and the application of HACCP methods (Hazard Analysis & Critical Control Point). Various inspection processes to identify the presence of foreign bodies, allergens or GMOs are also carried out. The product in its liquid form therefore contributes to the fluid’s easy filtration at various stages.

The installation continues to operate in a closed circuit until the product is dispensed into the mixer. This closed system ensures the food quality safety of the liquid yeast, which is therefore protected from exposure to the outside air. Moreover, the delivery of liquid yeast in bulk entails the use of vacuum-insulated tanks and an isolated network in order to maintain the yeast at a perfectly constant temperature. Lesaffre has established a certain number of very strict criteria for the choice of transporter and wash station.

Supply: the transportation of liquid yeast in bulk is governed by the Lesaffre quality policy. Apart from the rigorous selection of service providers, a number of different operating methods are outlined in detail including processes that involve the total traceability of the product.