I am currently in Year 12 (high school) and have been doing a wine-making experiment for chemistry. This has involved crushing grapes, taking their juices (removing the skins), pouring them into flasks and leaving them to ferment with yeast. The aim of our experiment was to see how the amount of tartaric acid added to the juices (before fermentation) affected the amount ethanol produced at the end of fermentation. In our experiment, we had six flasks each containing the juices; one control where no tartaric acid was added, and then in the other five flasks, tartaric acid added to them in increments of 5 ml. Our hypothesis was that because yeast has acid tolerance levels, there were be an optimum amount of acid to add to the juices which would produce the most amount of ethanol; too much acid, however, would result in less ethanol, as it is killing the yeast. We also had a null hypothesis, where we said that adding no tartaric acid to the juices would result in the most ethanol produced, meaning that the tartaric acid that was found naturally in the grapes was sufficient. The teacher made it a condition, however, the juice had to contain tartaric acid. Our teacher said that throughout his years of teaching, the results of almost all Year 12 wine-making experiments have contradicted their team's hypothesis (probably due to experimental error), and so he said if that was the case, we were allowed to tweak our results. The results, therefore, are not that important. There are two problems I am facing: 1. I have searched on the internet for resources that discuss and explain the effect of adding tartaric acid to grape juices before fermentation, yeast acid tolerance levels, and the amount of ethanol produced in fermentation, but I haven't found anything. Do you know of any resource that discusses and explains the chemistry behind something similar to our experiment? 2. To get a good grade, we need to include something in our assignment that we haven't been taught in class (something relevant to chemistry). This means any first-year or second-year university-level chemistry. Do you have any suggestions? Thank you very much.