Organic Chemistry


At first, the yeast did not change anything in the solution or the color of the bromothymol blue. Within half an hour, a bubble had formed in the bromothymol blue solution and came to the surface. Slowly, the bright blue solution began to turn green.  Small bubbles had formed along the sides of the mixture in the flask.  After 3 hours, the bubbles were continuously coming out of the tubing.  The bromothymol blue solution had turned a golden yellow.  The mixture was continuously bubbling. After 5 hours, the mixture continued bubbling and large bubbles formed along the sides.  24 hours later, the mixture had separated into layers.  The skins of the grapes were on top, what seemed to be the juice of the grapes was in the middle, and the yeast had settled all on the bottom.  There were still bubbles, but definitely fewer than before.  By the third day, a few skins had sunk.  Water was added and the yeast came to life a little bit again and a few bubbles appeared.  By the fourth day, all the grape skins had sunk to the bottom.  When more glucose was added, nothing really happened.