Buckwheat flour is ground from the seeds of a plant originating in Asia, has an earthy, slightly sour flavor that is usually tempered in commercial products by the addition of a little wheat flour
Mixture should be of a very firm batter consistency. Too hard and they come out small, too runny and the spaetzle pour through the holes. Comes with practice but you will learn. Try small batchs at first and you can thin it down or thicken with a little extra flour, until it is right.