Proziaki Proziaki Proziaki, soda bread - flour-based rolls with added sodium bicarbonate ("proza") originating from Subcarpathia in south-eastern Poland, also common in other parts of the country. Proziaki are produced by the use of wheat flour or wheat-secale flour, eggs, sour smietana (sour cream), water, salt and a maximum of one table spoon of sodium bicarbonate, baked on traditional tile-based cookers, heated by firewood. Proziaki can be circular shaped (diameter of 6-10 cm, thickness of around 1.5 cm) or quadrilateral. Presently, most proziaki are baked on an oven pan with a small amount of fat or lard ("smalec"). Sweet variants can
Sodium bicarbonate and allow passages for steam to escape, so the breading is not blown off during cooking. Baking powder, also sold for cooking, contains around 30% of bicarbonate, and various acidic ingredients which are activated by the addition of water, without the need for additional acids in the cooking medium. Many forms of baking powder contain sodium bicarbonate combined with calcium acid phosphate, sodium aluminium phosphate, or cream of tartar. Baking soda is alkaline; the acid used in baking powder avoids a metallic taste when the chemical change during baking creates sodium carbonate. Sodium bicarbonate can be used to kill cockroaches.