As a leavening agent, baker’s yeast converts sugar in the dough to carbon dioxide. The dough rises because of the bubbles of carbon dioxide becoming trapped during baking.
Yeast can be produced from a variety of raw materials containing sugar or starch. Mixtures of cane and beet molasses are the best choice for top product quality. Owing to circumstances, the sugars from molasses may be replaced by other sugar sources, such as hydrolysates from starch or even stale bread.
A complete yeast production line consists of custom equipment such as:
Waste water treatment is a necessity at most sites.
Molasses is clarified by sedimentation or mechanically, by separators, and sterilized with steam. Hydrolysates do not need any treatment but supplementation with nutrients, trace elements and vitamins.
The purified raw material is then mixed with nutrients in the fermenter.
Auxiliary substances such as urea are dissolved, sulphuric acid is diluted to be ready for the process.
Selected strains of Saccharomyces cerevisiae which develop the high rising power needed for top quality are used for bakery products.
Our yeast culture collection contains hundreds of different baker’s yeast strains. Be it wet or active dry yeast, we have the right strain for each type of feedstock, meaning that you can switch to make the most of the current market situation.
Choosing the ideal yeast strain for your application is key to producing a leavening agent with superior performance.
To start a new batch, a yeast inoculum is cultivated in the laboratory. The inoculum is used to seed a small fermenter with a capacity of 100 to 200 liters. The yeast from the latter is used to seed the next-largest fermenter until sufficient yeast has been produced to start fermentation in the production fermenter. This first batch, called seed yeast is separated in separators, washed and stored.
The seed yeast is used to start commercial yeast fermentations. One batch of seed yeast can be split into up to six portions, each of which are used to seed a commercial scale yeast fermentation process. When all seed yeast has been consumed, a new batch of seed yeast must be produced, starting with a fresh inoculum from the laboratory.
Commercial yeast is separated from the fermentation broth by nozzle separators. It is washed with process water and filtered to increase the dry matter content of the resulting yeast cream.
For wet compressed yeast, the filtered yeast cream passes through an extruder, and is pressed and cut into wet yeast blocks. These are packed, and need to be cold stored until use.
To produce instant active dry yeast (iADY), the wet yeast is processed in an extruder and carefully dried with hot air. A packing machine packs dried yeast airtight.
Baker's yeast products manufactured with VOGELBUSCH technology have different characteristics:
|Dry matter content (DMS)||28 to 34%||92 to 98%|
|Shelf live||up to 4 weeks||2 years and more|
|Storage conditions||refrigerated||room temperature|
We design our plants to create the perfect environment for high yeast growth and yeast quality. Measures include balancing stress-related process conditions in the fermenter such as oxygen and nutrition supply, and pH and temperature control.
We pay close attention to process economics, with low energy and utility consumption, and high yields, to optimize the long-term cost-benefit ratio of the plant.
Vogelbusch equipment that can greatly enhance process efficiency includes:
The most suitable aeration system is chosen based on fermentor size, production capacity and available utilities. Three types of tried and tested industrial aeration systems are available for specialized applications.
More about Aeration systems.
Sensor-equipped analyzers continuously measure the alcohol concentration in the fermenting mash. Gas phase measurement using semiconductor sensors is normally recommended for baker's yeast, but liquid-phase measurement with custom retractable probes is also available.
More about Gas analyzers.
Vogelbusch provides higly specialized services for yeast production plants including:
Our experts are also available for consultancy services such as strain supply and optimization, and laboratory and pilot plant testing.
Figures vary considerably depending on raw material, plant capacity and configuration as well as local conditions. To determine specific consumption figures, operating cost and investment cost, a feasibility study can be carried out for your particular case.
Following a feasibility study on the production of baker's yeast, the pre-engineering for a yeast plant designed for a daily capacity of 10,000 kg based on molasses was carried out in 2015.
SGP Cegro on behalf of AYS Algerian Yeast Society in 2014 ordered a feasibility study to investigate the production of 10,000 tons per year of baker's yeast to be made from imported molasses.
Razi Yeast & Alcohol Company, formerly Sugar Cane By-Products Corporation, assigned Vogelbusch with the process design, engineering and supply of a complete plant for the production of baker's yeast from cane molasses. Production in the yeast plant started in 2009, since manufacturing 32,000 kg per day of high quality instant active dry...
DHW of Hamburg decided to convert an existing fermenter to the Vogelbusch aeration system. The given situation required the redesign of the drive and included engineering and supply of the complete aerator system. The reconstructed fermenter has a capacity of 27,000 kg per day of baker’s yeast made from beet molasses....
DHW Nuremberg enhanced their manufacturing capacity by adding a fermenter which had to be placed outside the production building. Vogelbusch engineered the expansion and supplied the key equipment (EB4 aerator system including drive, mash pumps and heat exchangers). The fermenter is designed for 25,000 kg of baker's yeast per day made...
To raise the production capacity of Oriental Yeast in Osaka, Komatsugawa Chemical Engineering Co. assigned Vogelbusch with the engineering for an additional yeast fermenter and the supply of key equipment (aeration). The unit is designed for the production of 20,000 kg per day of baker's yeast made from cane molasses. Start-up...
Find out more about the processes used in yeast production:
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No. Yeast is manufactured in a fairly complex processing facility consisting of a range of process units.
No. Only molasses from a sugar factory can be used as it contains not only sugar but also specific nutrients required for yeast propagation.
Molasses from a sugar refinery (conversion of raw sugar into white sugar) can not be used.
It would be technically possible but is uneconomic in operation.
Yeast plants can be operated 24 hours per day, year round. Cycles of five or six days per week are also possible.
Technically speaking, a small yeast plant could have a capacity of only 1000 kg fresh yeast per day. Economically though, this can be recommended only under certain conditions, for instance for own requirements in a bakery.
To remain competitive in trade, the lower limit for an economically feasible production is in the range of 10 to 20 tons per day (wet).
Capital expenditure strongly depends on plant capacity and configuration as well as local conditions. Costs for the complete process plant (excluding land, buildings, waste water treatment and infrastructure) are from of euro 5 million upwards. This figure is for general reference only since each project has its own particularities that need consideration.
Large quantities of drinking water are required in production and subsequentl, large volumes of waste water are produced that need treatment.
The plant site therefore has to have a reliable source of potable water and a waste water treatment facility has to be foreseen.
For a small sized factory an area of 100 x 75 m is necessary.
With permits on hand engineering and construction takes 18 - 24 months.
Complete our design questionnaire (check Links & Downloads section above) and send it back to us to get a professional opinion on your project.