Checked biscuits have small cracks or hairlines in them, sometimes hardly visible. Problem appears mostly in short period after packaging, when opening a package and/or touching the product the biscuits will break; in developing products it will occur during cooling stage as well. Mainly with hard sweet biscuits and enzyme modified crackers and possible with rotary moulded biscuits, extruded and sheeted/ laminated biscuits or crackers.
Very often it starts in the batch size, where either ingredients could vary (e.g. flour) or that due to the changing conditions certain adjustment are made, such as water levels or temperature. Also it could have to do with how and in what condition the return dough is being reprocessed.
Certain conditions facilitate the hairlines, such as higher protein levels, certain sugar replacers or in the case of sheeting the molding design in combination with the return dough web.
Research has shown that the result is very often an uneven distribution of amongst other moisture inside the biscuit or cracker and on the other hand the hydrophilic behaviour of another part. Solutions could lie in changing leavening systems, flour/ starch ratios, but also conditions as introducing dough relaxation, slower cooling, changing oven belt, sometimes in combination with slower baking at lower temperatures or introduce an enzyme.