Final answer:
Both molasses and cane juice must be diluted with water for effective fermentation in rum production to reduce the sugar concentration to a level that the yeast can tolerate and function properly.
Step-by-step explanation:
In rum production, both molasses and cane juice must be diluted with water to reduce the percentage of sugar and allow effective fermentation. This is necessary because rum is made by fermenting and then distilling sugarcane by-products like molasses or directly from cane juice. If the sugar concentration is too high in the solution, it can inhibit the yeast and prevent it from fermenting properly. Yeast can only tolerate certain levels of sugar and alcohol; hence, diluting these raw materials ensures that the yeast can survive and facilitate the fermentation process that eventually produces rum.
During the fermentation process, the sugar in the diluted molasses or cane juice is converted by the yeast into alcohol and carbon dioxide. Therefore, the answer to the student's question is that both molasses and cane juice must be diluted with water for effective fermentation in rum production.