zauche test involves taking a 500 mg dry weight sample of organic component 18 and soaking it in 20 ml of 0 0993 m acidic acid for one hour while the solution or suspension is soaking it is stirred with a magnetic stir bar upon completion of the one hour soaking period the suspension is vacuum filtered through a whatman 1 filter paper the remaining solids collected by the filter are rinsed with 160 ml of de ionized water the rinse water is combined with the filtrate and is then titrated with 0 133 m sodium hydroxide while measuring the rinse water 39 s ph the ph is plotted as a function of the quantity of the sodium hydroxide as shown in fig4 curve 58 represents a zauche test performed on a sample of anaerobically digested solids which comprise the organic component of mix a 10 a mix b 10 b and mix d 10 d the greatest slope of curve 58 is identified as point 60 which corresponds to 8 ml or an acid buffering coefficient of 8 on an x axis 62 of fig4 thus organic component 18 e g anaerobically digested manure has an acid buffering coefficient of 8 curve 64 represents a zauche test performed on conventional compost e g aerobically decomposed manure the steepest point of curve 64 is at point 66 which indicates that the compost sample has an acid buffering coefficient of 13 curve 68 represents a zauche test performed on a sample of peat moss the steepest point of curve 68 is at point 70 which indicates that the peat sample has an acid buffering coefficient of 14 this means that the.