Growing S.C.O.B.Y
Catherine (Zoe) Ng
Sir Winston Churchill Secondary
Floor Location : J 101 D

My question was “How does the amount of sugar affect the growth of SCOBY?”. A SCOBY (symbiotic culture of bacteria and yeast) is the living home for bacteria and yeast. I hypothesised if I put in more sugar in the tea mixture then the SCOBY will be larger in mass, because SCOBY grows from fermentation. So if I give the SCOBY more sugar then I think it will ferment faster therefore making it the largest within three weeks. I conducted my experiment by first making a tea mixture. To make the tea mixture you have to make 3 ½ cups of black tea per jar for 4 jars (litre jar). Then mix in 3/8 cup of sugar in the first jar, 2/8 in the second, 1/8 in the third, and then leave the last jar without sugar. Lastly I had to mix in ½ cup of unpasteurized kombucha. Then I observed my mixtures for three weeks. Within the first few days my cabinet smelled like apple cider vinegar and there were small bubbles on the top of all the jars. Near a week to a week and a half they developed bigger bubbles. Then nearing the two week mark, the mixture started developing a thin layer of SCOBY. At the end of three weeks I weighed my SCOBYs. In trial one the order from weighing the most mass to least was 3/8 cup of sugar (8.43g), 1/8 cup of sugar (5.58g), 2/8 cup of sugar (3.56g), then no sugar (0g). Trial two was 2/8 cup of sugar (5.23g), 3/8 cup of sugar (3.91g), 1/8 cup of sugar (3.11g), then no sugar (0g). Trial three was 3/8 cup of sugar (9.26g), 1/8 cup of sugar (1.90g), 2/8 cup of sugar (1.29g), then no sugar (0g). My results tell me that 3/8 cup of sugar will always weigh more than 1/8, but 2/8 cup is inconsistent. My hypothesis was wrong. I hypothesised that the more sugar you add the faster the SCOBY will grow. I can't say more sugar makes the SCOBY larger because in one trial the 2/8 SCOBY was smaller than the 1/8, so my hypothesis was wrong. However I also can’t say that less sugar causes the SCOBY to be bigger, because the 3/8 was always larger than the 1/8. So in conclusion I did not answer my question because my results were inconclusive. However if you want to grow a SCOBY, I would use 3/8 cup of sugar because on average it is the largest and it is the most consistent.