Bread ingredients include milk, sugar, flour and salt. Which of these is needed for maximum fermentation by the yeast? What tests could be done in the lab? Will yeast react differently with different amounts of the other ingrediants? We did the lab and cut down the amounts of sugar, salt and milk. We had different results but do not know exactly why it happened. What reacted with what to form more corbon dioxide to make the dough rise more. What produced lactate, and what did the sugar react with the yeast or something elese?