Yes, but it needs to be a really warm ambient. You may need to use either some sugar and yogurt or yeast (fresh or dry). So, mix 60 ml water + 60 g wholegrain flour + 1 tbsp yeast, and 1 tsp sugar. It will make an amazing starter but it will not be a yeast-free one. * using any wholemeal or whole-grain flour helps with speeding the process.