Using more starter tea when starting a batch of kombucha may help to reduce the risk of mold growth, as the starter tea contains a high concentration of beneficial bacteria and yeast. These bacteria and yeast can help to inhibit the growth of unwanted mold or bacteria and promote a healthy fermentation process.However, it is important to note that there are other factors that can affect the risk of mold growth in kombucha. These include:The cleanliness of the brewing equipment and surfaces: Using clean and sanitized equipment and surfaces can help to prevent the growth of unwanted bacteria or mold.The pH of the kombucha: The pH of the kombucha should be around 3.5-4.0 to prevent the growth of unwanted bacteria or mold.The temperature of the fermentation: The fermentation should take place at a consistent temperature (around 70-75°F is ideal) to promote a healthy fermentation process and prevent the growth of unwanted bacteria or mold.The duration of the fermentation: Allowing the kombucha to ferment for the appropriate amount of time can help to prevent the growth of unwanted bacteria or mold.By using more starter tea and following good sanitation practices, you can help to reduce the risk of mold growth in your kombucha. However, it is important to pay attention to all of the factors that can affect the risk of mold growth to ensure a healthy fermentation process.