It is often necessary to thicken insoluble parts of the suspension like spent grains, operational yeast, mash etc.. in the fermenting laboratory. Flushing with condensed liquid (membrane pump) or sucking with Buchner funnel is used most often for this purpose but it lasts inordinately long time and weighs water pump on excessive water consumption (water pump). On the other hand the pressure-press makes use of pressure of water in the water piping, water consumption is practically zero and time period of press is 15 - 20 min. Fill the press with thickening suspension, put the piston in and connect the press to the water pressure supply. Basic filtration obstacle is made of inserted filter paper or cloth.
We can take as an example preparation of compressed brewery yeast of collected yeast after fermentation with dry solids 8-10%. The yeast is thickened to receive 30% of dry solids and can be dosed directly into the hopped wort and beer during determination of obtainable fermentation grade which is very common analysis in the brewer's laboratory. Useful volume of the press is about 250ml of the non-thickened suspension.