The article mentions results from changes of physical properties of com-posted material during the composting process. Composting conditions in compost pile were simulated in five vessels with volume of 90 m3 under home conditions. Composted material was variously modified (mixing and turning, moistening, add-ing fresh material) during the composting process. Temperature and oxygen con-centration inside vessels were measured, as well as reduction in volume of compost material during time, pH and electric conductivity of selected compost.
It appeared that the temperature of the compost material in small volume in the compost pile was lower than the requirement for hygienization of the composted material. The temperature higher than 50°C was measured only sporadically and already during the first week of the experiment temperatures inside the vessels corresponded with outside temperatures.
Oxygen concentration in all vessels was sufficient to ensure the aerobic process during the entire period of the experiment. The lowest measured oxygen concentration was higher than 10 %. These low values were measured only during the first week of the experiment, during the following weeks the oxygen concen-trations exceeded 15% only with small exceptions.
Reduction in volume of the composted material highly depended on whether the compost material was mixed and turned during the course of the composting process. Mixed and turned composted material was reducing its volume significantly, quicker than the composted material not being mixed and turned. The effect of moistening on the composted material was not proved.
Measured pH values and electric conductivity (EC) values of the compost material from selected vessel K2 (composted material being mixed and turned, moistened, fresh compost material was not added) showed values fully corre-sponding with a quality well-matured compost. The average pH value was 7.76 with a standard deviation of 0.04 and the average EC value was 1.79 mS.cm-1 with a standard deviation of 0.27.