A method for the aseptic heating of a liquid product in a heat exchanger unit, designed as a tube heat exchanger, of the heating zone of an assembly in a UHT system, wherein an indirect exchange of heat occurs at a wall in the heat exchanger unit between the liquid product and a heating medium such that a single heating medium flow (F M) flowing in a heat-releasing heating medium chamber (22.2) at a heating medium inlet temperature (T ME) between a heating medium inlet (E M) and a heating medium outlet (A M) of the heat exchanger unit is guided in a countercurrent to a single product flow (F P) flowing in a heat-absorbing product chamber (22.1) between a product inlet (E P) and a product outlet (A P) of the heat exchanger unit, wherein an overall heat exchanging path is formed between the product inlet and outlet (E P, A P), wherein the product flow (F P) is heated from a product inlet temperature (T PE) to a product outlet temperature (T PA), and wherein at least the product outlet temperature (T PA) and the heating medium inlet temperature (T ME) are monitored and regulated, characterized by the following method steps: adjusting an unknown product-specific temperature profile ([T P (I x)] PE-PA) between the product inlet temperature (T PE) and the project outlet temperature (T PA) with the assistance of a supply of the required heating medium flow (F M) at the required heating medium inlet temperature (T ME) to the heating medium entrance (E M) in the heating medium chamber (22.2), and measuring discrete product temperatures (T P; T P1 to T Pn) at given measuring points (22.3) in the product flow (F P); specifying the product inlet temperature (T PE) at the product inlet (E P) into the, and the product outlet temperature (T PA) at the product outlet (A P) out of the product chamber (22.1), and providing the heating medium inlet temperature (T ME) and the heating medium flow (F M); measuring a product-specific temperature profile (T P (I X) between the product outlet (A P) and the product inlet (E P) at the given measuring points (22.3); comparing the temperature profiles from the method steps and, and calculating each of the temperature deviations (ΔT P) at the given measuring points (22.3); specifying a permissible temperature deviation ([ΔT P] o); modifying the heating medium inlet temperature (T ME) to a target heating medium inlet temperature (T ME *) if the permissible temperature deviation ([ΔT P] o) is exceeded by the calculated temperature deviation (ΔT P). adjusting an unknown product-specific temperature profile ([T P (I x)] PE-PA) between the product inlet temperature (T PE) and the project outlet temperature (T PA) with the assistance of a supply of the required heating medium flow (F M) at the required heating medium inlet temperature (T ME) to the heating medium entrance (E M) in the heating medium chamber (22.2), and measuring discrete product temperatures (T P; T P1 to T Pn) at given measuring points (22.3) in the product flow (F P); specifying the product inlet temperature (T PE) at the product inlet (E P) into the, and the product outlet temperature (T PA) at the product outlet (A P) out of the product chamber (22.1), and providing the heating medium inlet temperature (T ME) and the heating medium flow (F M); measuring a product-specific temperature profile (T P (I X) between the product outlet (A P) and the product inlet (E P) at the given measuring points (22.3); comparing the temperature profiles from the method steps and, and calculating each of the temperature deviations (ΔT P) at the given measuring points (22.3); specifying a permissible temperature deviation ([ΔT P] o); modifying the heating medium inlet temperature (T ME) to a target heating medium inlet temperature (T ME *) if the permissible temperature deviation ([ΔT P] o) is exceeded by the calculated temperature deviation (ΔT P).