Water is the simplest ingredient on a label, but in baked goods it does a lot of work. Mixed with wheat flour it lets the proteins form gluten, an elastic network that holds gas; in the oven it lets the starch swell and set; and it dissolves sugar and salt so they spread evenly. In yeast doughs it also wakes the yeast up so fermentation can start.
In a pastry such as the Today - Croissant Chocolate and Hazelnut & Vanilla Cream Filling, water in the dough turns to steam during baking and helps the layers puff and separate. Much of it evaporates, but what remains decides how soft the pastry feels and how long it stays that way, which is why packaged croissants like this one also use humectants to hold on to moisture.
Water contains no calories and no allergens. In food factories it must be of drinking-water quality.
