The various biomass feedstocks that can be used for bioethanol production are divided into two major groups: first generation feedstocks and second (next) generation feedstocks. First generation feedstocks include sugar, sugar cane, sugar beet and starch crops like corn, wheat and barley. To the next generation feedstocks belong wood, grasses, forestry residues and other lignocellulosic materials as new, more sophisticated conversion technologies are developed to enable the production of bioethanol from cellulosic feedstocks. However, feedstock availability for ethanol production can be limited in some countries with low biomass resources, e. g. woody biomass resources in Finland and Sweden are huge however the woody biomass has been used in many ways such as fuel pellet production for combustion and electricity production and lignocellulosic materials have been used for many years in paper mills. In fact, the price of the feedstock is about one-third the cost of bioethanol production (Balat, Balat, and Oz, 2008) depending on feedstock. In addition, there are other aspects of feedstock production that should be considered such as national and international regulations and policies, environmental questions, protection of high-value habitats and competition between food production and biofuel feedstock. It is also important to be able to determine the chemical composition of a feedstock (i. e. sugar units, extractives, lignin, etc.) by fast and non-destructive methods such as near infrared spectroscopy (NIR; Sanderson, Agblevor, Collins, and Johns, 1996).

There are three different groups of feedstocks available for ethanol production: sugar feedstock such as sugarcane and sugar beet; starch feedstock such as cereal grains and potatoes; and cellulose feedstock such as forest products and agricultural residues. In general, the sucrose-containing materials such as sugarcane allow the production of ethanol for the lowest costs compared to the starchy materials and lignocellulosic feedstocks.