Freeze concentration method (also called cryoconcentration) has two ramifications: the heat of water crystal formation can be withdrawn directly, by vacuum evaporation of a certain part of water from the liquid material (food), or indirectly, by means of a cooling agent separated from the product by a heat-conducting wall. Indirect crystallizers are preferable, in our opinion, because they conserve all volatile aromas (without any aroma returning systems).  Calculation of the contact freezing process allows optimizing of the concentrator design. From the general reasons follows that for intensifying the cryoconcentration process it is necessary to expend the phases contact area (that means, in the case of cylindrical surface of sedimentation, constructive increase in the number of heat-removing pipes at reduction of their diameter). For thermotechnical optimization of the cryoconcentrator design it is enough to analyze heat transfer at the instant thickness of ice and to solve analytically the simpler stationary problem of heat conductivity - instead of the complex non-stationary problem.