The traditional method is solid state fermentation on rice in tray bioreactors . Scaling up essentially involves putting in more trays. Industrial production is nowadays mainly done by submerged fermentation in stirred tanks, with either sugars (e.g. glucose or solid (e.g. ground rice) as the carbon source. Scale up appears to be determined by both oxygen trannsfer rate (oxygen is needed to achieve high pigment production rates) and the amount of shear (too high a shear level may cause breakage of mycelia).
Monacolin produced by Monascus is not a pigment. Monacolin is a statin molecule that is involved in the inhibition of cholesterol biosynthesis. The industrial process for producing different metabolites by Monascus is solid state fermentation on different substrates, but today there are patented processes for the production of Monascus pigments in submerged culture.