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
Quark-nova of the projected neutron star population. A conservative estimate based on this, indicates that up to two quark-novae may occur in the observable universe each day. Theoretically, quark stars would be radio-quiet, so radio-quiet neutron stars may be quark stars. Direct evidence for quark-novae is scant; however, recent observations of supernovae SN 2006gy, SN 2005gj and SN 2005ap may point to their existence. Quark-nova A quark-nova is the hypothetical violent explosion resulting from the conversion of a neutron star to a quark star. Analogous to a supernova heralding the birth of a neutron star, a quark nova signals the creation