TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: The starch-containing plant material is a transgenic plant part comprising a polynucleotide encoding at least the first class of alpha -amylase enzymes, where the method includes one or more liquefaction steps that are performed under conditions sufficient for the encoded first class of alpha -amylase enzymes to hydrolyze the starch-containing plant material. The first class of alpha -amylase enzymes is exogenously-added alpha -amylase. The starch-containing plant material comprises a transgenic plant part containing a polynucleotide encoding at least the second class of alpha -amylase enzymes, where the process includes one or more liquefaction steps that are performed under conditions sufficient for the encoded first and second classes of alpha -amylase enzymes to hydrolyze the starch-containing plant material. At least the second class of alpha -amylase enzyme is exogenously-added to the slurry in a liquefaction step. The enzymes of one class of alpha -amylase enzymes exhibits unimodal starch hydrolysis pattern. The starch hydrolysis pattern is determined by analyzing the distribution of oligosaccharides resulting from hydrolysis of starch by each of the alpha -amylase enzymes to dextrose equivalent (DE) of 10-15. The hydrolysis of starch by the class of alpha -amylase enzyme exhibiting a unimodal starch hydrolysis pattern results in a majority of hydrolysates that are in the lower size range. The lower size range is DP1-DP30 .The hydrolysis of starch by the class of alpha -amylase enzyme exhibiting a bimodal starch hydrolysis pattern results in hydrolysates that are in both the lower and the higher size ranges. The lower size range is DP1-DP30, and the higher size range is greater than DP30. The class of alpha -amylase enzymes that exhibits a unimodal starch hydrolysis pattern comprises an alpha -amylase enzyme derived from a microorganism of the order Themococcales and the enzyme that exhibits a bimodal starch hydrolysis pattern comprises an alpha -amylase enzyme derived from Bacillus microorganism. The class of amylase enzymes that exhibits a unimodal starch hydrolysis pattern comprises alpha -amylase enzyme chosen from 797GL3 alpha -amylase enzyme and D45 alpha -amylase enzyme. The method (M2) further involves performing saccharification process in presence of glucoamylase, where the saccharification process can be performed simultaneously with liquefaction or fermentation process, or between liquefaction and fermentation process. The amount of biofuel obtained in fermentation process is greater than the amount of biofuel obtained from fermentation of hydrolyzed starch and sugars resulting from liquefaction and saccharification of an aqueous slurry of starch-containing plant material in the presence of two or more classes of alpha -amylase enzymes that have similar starch hydrolysis patterns, or in presence of either the first or second class of alpha -amylase enzymes alone. The amount of residual sugar remaining after fermentation process is less than the amount of residual sugar remaining after fermentation of hydrolyzed starch and sugars resulting from liquefaction and saccharification of an aqueous slurry of starch-containing plant in the presence of two or more classes of alpha -amylase enzymes that have similar starch hydrolysis patterns, or in presence of either the first or second class of alpha -amylase enzymes alone. The fermentation is yeast fermentation. Preferred Plants: The starch-containing plant material is derived from plant chosen from rice, barley, potato, sweet potato, canola, sunflower, rye, oats, wheat, corn, soybean, sugar beet, tobacco, Miscanthus grass, switch grass, safflower, trees, cotton, cassava, tomato, sorghum, alfalfa, and sugarcane. Preferred Microorganisms: The Bacillus microorganism is chosen from B.licheniformis and B. amyloliquefaciens. EXAMPLE - No suitable example given.