Bread unpredictable since the steam is not produced until the bread is baked. Steam leavening happens regardless of the raising agents (baking soda, yeast, baking powder, sour dough, beaten egg white) included in the mix. The leavening agent either contains air bubbles or generates carbon dioxide. The heat vaporises the water from the inner surface of the bubbles within the dough. The steam expands and makes the bread rise. This is the main factor in the rising of bread once it has been put in the oven. CO generation, on its own, is too small to account for the rise. Heat
Finnish bread traditional in Finland, and it makes the best of the humidity preserving qualities of traditional rye bread by serving each piece of bread as a pre-cut pair of two halves, which protect each other but can still be easily separated. The brand is not without competitors. Two of them are Fazer's "Ruispuikulat" (a newer competitor), which are oblong in shape instead, and Oululainen's "Reissumies" (preceding Vaasa's formulation by about a decade), which are round. Both competitors are distinctly more traditional in formulation than Ruispala, mainly changing the size and shape of the traditional rye bread. As rye bread is the