Methods of pitching for fermentation, and related methods of fermentation and systems

Abstract

The present invention relates to methods and systems of pitching yeast to fermentation reactors. More particularly, the present invention involves pitching yeast from one fermentation tank to at least one additional fermentation tank. Advantageously, yeast can be continuously pitched from fermentor to fermentor for as long as practically desirable.

What is claimed is: 
     
         1 . A method of fermenting, the method comprising:
 providing fermentable aqueous composition in a first fermentation reactor,   fermenting the fermentable aqueous composition in the first fermentation reactor to produce a fermentation product;   removing a fraction of the fermentable aqueous composition from the first fermentation reactor, wherein the fraction of the fermentable aqueous composition comprises a first concentration of fermentation product;   combining the fraction of the fermentable aqueous composition in a second fermentation reactor with added fermentable aqueous composition;   fermenting the fermentable aqueous composition in the second fermentation reactor to produce a second beer composition;   continuing to ferment the fermentable aqueous composition in the first fermentation reactor, after removing the fraction of the fermentable aqueous composition, to produce a first beer composition, wherein the first beer composition comprises a second concentration of fermentation product, and wherein the second concentration is greater than the first concentration of fermentation product in the fraction of the fermentable aqueous composition;   removing the first beer composition from the first fermentation reactor and transferring the removed first beer composition downstream from fermentation to recover fermentation product from the first beer composition; and   removing the second beer composition from the second fermentation reactor and transferring the removed second beer composition downstream from fermentation to recover fermentation product from the second beer composition.   
     
     
         2 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation reactor at least 8 hours after the fermentable aqueous composition is provided in the first fermentation reactor. 
     
     
         3 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation reactor after the first fermentation reactor is filled with fermentable aqueous composition. 
     
     
         4 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation reactor while the first fermentation reactor is filling with fermentable aqueous composition. 
     
     
         5 . The method of  claim 4 , wherein the first fermentation reactor is filled with additional fermentable aqueous composition after the fraction of the fermentable aqueous composition is removed from the first fermentation reactor. 
     
     
         6 . The method of  claim 4 , wherein the fermentable aqueous composition comprises a slurry comprising processed plant material. 
     
     
         7 . The method of  claim 1 , wherein combining the fraction of the fermentable aqueous composition in a second fermentation reactor with added fermentable aqueous composition comprises adding the fraction of the fermentable aqueous composition to the second fermentation reactor and filling the second fermentation reactor with added fermentable aqueous composition. 
     
     
         8 . The method of  claim 1 , wherein the first fermentation reactor and the second fermentation reactor are operated according to a batch process. 
     
     
         9 . The method of  claim 1 , fermenting the fermentable aqueous composition in the first fermentation reactor to produce a fermentation product comprises exposing the fermentable aqueous composition to a temperature in a range from 15° C. to 50° C. for a time period in a range from 5 to 30 hours. 
     
     
         10 . The method of  claim 1 , further comprising, prior to producing the second beer composition,
 removing a fraction of the fermentable aqueous composition from the second fermentation reactor, wherein the fraction of the fermentable aqueous composition comprises a first concentration of fermentation product; and   combining the fraction of the fermentable aqueous composition from the second fermentation reactor in a third fermentation reactor with added fermentable aqueous composition.   
     
     
         11 . The method of  claim 1 , further comprising, prior to providing fermentable aqueous composition in a first fermentation reactor:
 providing an initial pitching aqueous composition in a yeast conditioning reactor and/or an aerobic yeast propagation reactor, wherein the initial pitching aqueous composition comprises a slurry comprising yeast, water and processed plant material comprising an amount of at least one monosaccharide; and   removing the initial pitching aqueous composition from the yeast conditioning reactor and/or aerobic yeast propagation reactor and adding the initial pitching aqueous composition to the first fermentation reactor to provide a portion of the fermentable aqueous composition in the first fermentation reactor.   
     
     
         12 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition from the first fermentation reactor has a volume in a range from 5,000 gallons to 100,000 gallons. 
     
     
         13 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition from the first fermentation reactor has a volume in a range from 10,000 gallons to 40,000 gallons. 
     
     
         14 . The method of  claim 1 , wherein the first fermentation reactor has a volume in a range from 100,000 gallons to 750,000 gallons. 
     
     
         15 . The method of  claim 1 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation reactor from 8 hours to 24 hours after fermenting the fermentable aqueous composition in the first fermentation reactor to produce a fermentation product. 
     
     
         16 . A method of fermenting, the method comprising:
 providing fermentable aqueous composition in a first fermentation system,   fermenting the fermentable aqueous composition in the first fermentation system to produce a fermentation product;   removing a fraction of the fermentable aqueous composition from the first fermentation system, wherein the fraction of the fermentable aqueous composition comprises a first concentration of fermentation product;   combining the fraction of the fermentable aqueous composition in a second fermentation system with added fermentable aqueous composition;   fermenting the fermentable aqueous composition in the second fermentation system to produce a second beer composition;   continuing to ferment the fermentable aqueous composition in the first fermentation system, after removing the fraction of the fermentable aqueous composition, to produce a first beer composition, wherein the first beer composition comprises a second concentration of fermentation product, and wherein the second concentration is greater than the first concentration of fermentation product in the fraction of the fermentable aqueous composition;   removing the first beer composition from the first fermentation system and transferring the removed first beer composition downstream from fermentation to recover fermentation product from the first beer composition; and   removing the second beer composition from the second fermentation system and transferring the removed second beer composition downstream from fermentation to recover fermentation product from the second beer composition.   
     
     
         17 . The method of  claim 16 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation system after the first fermentation system is filled with fermentable aqueous composition. 
     
     
         18 . The method of  claim 16 , wherein the fraction of the fermentable aqueous composition is removed from the first fermentation system while the first fermentation system is filling with fermentable aqueous composition. 
     
     
         19 . The method of  claim 18 , wherein the first fermentation system is filled with additional fermentable aqueous composition after the fraction of the fermentable aqueous composition is removed from the first fermentation system. 
     
     
         20 . The method of  claim 16 , wherein combining the fraction of the fermentable aqueous composition in a second fermentation system with added fermentable aqueous composition comprises adding the fraction of the fermentable aqueous composition to the second fermentation system and filling the second fermentation system with added fermentable aqueous composition.