Any nuts or seeds can be used in the recipe. If you choose a shorter fermentation period, it will produce a less tangy taste, while a 24-hour fermentation will create a more noticeable sourdough flavor. I opted to go all out on the first attempt and why not? Go big or go SOUR! When the granola was done, I kept it in the warm oven overnight to dry out even more. It was perfect and warm in the morning. What a treat! While the low heat method might be necessary for this granola, next time I will try 300F for 1 hour and see what happens.