Quark (dairy product) 6.1). Acidification allowed to continues until the pH reaches around 4.6, at which acidity level the casein proteins in the milk begins to precipitate. In Germany, the curd is continuously stirred to prevent it from getting hard, resulting in a thick, creamy texture. According to German regulations on cheese ("Käseverordnung"), "fresh cheeses" ("Frischkäse") such as quark or cottage cheese must contain at least 73% water in the fat-free component. German quark is usually sold in plastic tubs with most or all of the whey. This type of quark has the firmness of sour cream but is slightly drier, resulting in
Strange quark values of + and − respectively. Along with the charm quark, it is part of the second generation of matter, and has an electric charge of − "e" and a bare mass of . Like all quarks, the strange quark is an elementary fermion with spin , and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. The antiparticle of the strange quark is the strange antiquark (sometimes called "antistrange quark" or simply "antistrange"), which differs from it only in that some of its properties have equal magnitude but opposite sign. The first strange particle (a particle