Recipe(tried): No problem using the Kitchenaid stainless steel bowl for Sourdough starter

I have used my Kitchenaid stainless steel mixing bowl to grow and mix my sourdough starter for about 5 years with no problems. I store the starter in the fridge in a glass mason jar. When I want to make bread, I pour the starter into the Kitchenaid stainless steel mixing bowl, add more flour and bottled water and mix it. I then place the Kitchenaid stainless steel mixing bowl of starter in an OFF oven with the oven light on, for warmth, for about 4 to 6 hours until the starter is active and bubbly. I then use the Kitchenaid stainless steel mixing bowl in the mixer to mix and knead the sourdough bread. It always turns out great and doesn't hurt my starter. I use Carl's 1847 Oregon Trail sourdough starter.