Many regions and countries use beer in their batters: it acts as a leavening and puffs up instantly, reducing the waiting and handling time.
Since no more than 3 or 4 fritters can be cooked at a time, Dutch cooks turn their ovens on to low and place a cookie sheet lined with two layers of paper towels in the oven. After each batch is cooked, the fritters are placed in the oven to keep warm, where they stay crisp and less oily.