AIP Conference Proceedings [AIP Publishing THE 2018 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the Universiti Kebangsaan Malaysia, Faculty of Science and Technology 2018 Postgraduate Colloquium - Selangor, Malaysia (4–6 April 2018)] THE 2018 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the Universiti Kebangsaan Malaysia, Faculty of Science and Technology 2018 Postgraduate Colloquium - Effects of medium variation and fermentation time towards the pH level and ethanol content of Kombucha