Abstract: This invention makes it possible for an accurate, reliable and repeatable method for determining the amount of “doneness” imparted to bread or bread-like substances when toasting. The ionization sensor reacts to the quantity of carbonaceous material emitted from the food product as it is toasted. Different recipes or compositions of bread or bread-like substances will all contain varying quantities of compounds and moisture that will carbonize differently when heated, as such, the ionization sensor will enable a “true” indication the amount of “doneness” unaffected by composition.