The invention provides a method and system for controlling the conversion of crystalline insoluble cellulose to an organic product in a bioreactor containing crystalline insoluble cellulose and a culture medium. A processor of a computing device receives an input from a sensor in the bioreactor. The input may be a measurement of one or more of concentration, temperature, pH and pressure. The processor calculates conversion of cellulose using the input to provide a total calculated organic product in the bioreactor. The processor receives a further input from a sensor in the bioreactor of the total actual organic product and compares the total calculated organic product and the total actual organic product. The processor then transmits an instruction to an agitator associated with the bioreactor to control agitation of the content of the bioreactor if the total actual organic product is outside a predetermined range of the total calculated organic product.