Some liquid foods, such as oils, honey, ketchup, jam, juices or syrup, flow more slowly than other liquids. The resistance of the foodstuffs in liquid form with a physically homogeneous structure to viscosity is called viscosity. That is to say, the degree of resistance of liquid materials to flow against a force applied is called viscosity.

Many different methods and devices have been developed to measure the viscosity of homogeneous liquids. For example, one of the means of measuring viscosity may be to determine the viscosity by measuring the rate at which the liquid passes through a vertical tube. The passage time of a certain amount of liquid through the tube indicates the viscosity value of that liquid. The acceleration of a round object passing through a stationary liquid also gives the viscosity of that liquid.

Viscosity is briefly a feature of fluids. It is defined as the resistance of fluids to flow or internal friction. Liquid molecules slide on top of each other and try to prevent them from gaining speed relative to each other. Therefore, friction occurs between molecules. If this friction decreases, the flowability of liquids increases, ie their viscosity decreases. Temperature is one of the factors affecting viscosity. The higher the temperature, the lower the viscosity of the liquids. On the other hand, the higher the pressure, the higher the viscosity of the liquid. As the pressure increases, the number of voids in the liquid decreases and the movement of molecules becomes difficult.

When evaluating the structure of any liquid, the viscosity of that liquid is determined with the aid of viscosity. For example, when transporting liquids such as mineral oil or chemicals through pipelines, the viscosity of that liquid is important. If the viscosity is low, pump efficiency decreases and speed decreases.

Viscosity determination of liquids is also carried out in the authorized laboratories within the scope of physical analyzes. In this study, the standards issued by domestic and foreign organizations are complied with. Generally accepted test methods and test criteria are also complied with.