An algorithm for production of a liquid humic fertilizer (from the waste of the biotechnological manufacturing of a biological-origin liquid-phase biological product) has been presented. The algorithm includes factors affecting end-product qualities such as extraction agent concentration and volume, extraction temperature, etc. The work has several stages. The quality of the experimental samples of the liquid humic fertilizer has been assessed at each stage. Having taken account of all the results, the following optimum parameters for the liquid humic fertilizer have been evaluated: a thrice-repeated alkali extraction with a 1.5% potassium hydroxide solution at the waste:KOH ratio = 1:10 at the temperature of 60 0С for six hours. The mother liquor of the liquid humic fertilizer was dark brown and had no bad odor. Potassium humate, humic acid and spore-formers concentrations in the fertilizer were at least 17 g/l, at least 2.7 g/l and at least n*102 colony-forming units/ml, respectively. The liquid humic fertilizer was recommended for a root or out-of-root feeding of plants, as well as to activate soil microorganism effects.