Today in 1929, US Patent 1718910 A was issued, an invention of Lucien Lavedan, for his “Process of Manufacturing Yeast.” There’s no Abstract, although in the description it includes this summary:

The primary object of my invention is to provide a process in which carbon dioxide is employed to more effectively carry out in the most suitable and efficient manner, the’ continuous process of making yeast with continuous aeration in propagating pure yeast in a pure sugared liquid of a given density in the presence of nutritive salts and air; with the separation of the scum containing the yeast thus propagated Jfrom the main body of the liquid, and subsequent separation of the yeast cells from the associated liquid o the scum, with the addition of sufficient sugared solution to the separated liquid to bring the main sugared solution to its original density when the separated liquid is returned to it, as described in my Letters Patent- No. 1,201,062, on a continuous process with continuous aeration, granted October 10, 1916, the cold carbon dioxide acting as a suitable agent to neutralize an excess of alkalinity, and at the same time operating to reduce the temperature of the Wort.

Another object of`my invention is to provide a process to produce from a given amount of raw materials, the highest possible yield of yeast possessing an increased vitality and strength for baking, fermenting, diet and any other uses, while simultaneously decreasing the production of alcohol.

A further object of my invention is to produce yeast which will keep for a longer period of time than yeast produced by other processes and methods.

A further object of my invention is to produce yeast possessing a higher vitamin E and nutrient value, and far more suitable to be used for eating purposes as it is more adapted to conditions existing in the human stomach, more palatable and of better odor and taste, and possesses a more effective action than any other yeast produced by other processes and methods.