Issues connected with expired food products are a significant, however underestimated, problem. Currently, expired food, disposed of by manufacturing industry plans, trade and gastronomy, comprises the biggest content of waste. In retail chains such products are withdrawn from the sale and become waste, which should be managed properly. Expired food cannot be again introduced to the market or be sold on reduced price or on special offers. Possibilities to use fermentation may enable both utilization of expired food and biogas acquisition – a source of renewable energy. Therefore, fermentation plays three important roles. Firstly, it is a method of converting the energy from expired food into useful fuel, i.e. biogas which can be stored and transported. Secondly, this is a method aiming at recycling organic waste into stable soil improvers, liquid fertilizers and energy. And thirdly, it is a method of waste inertisation with the objective to decrease adverse influence on the environment. This article indicates possibilities to obtain biogas from three selected mixtures of expired food products.