Combine yeast and 1/2 cup lukewarm water from the 1 cup of water and put aside
In mixer bowl, combine oil, sugar, salt, and beaten eggs and mix at mediium speed for about 5 mnutes.Alternately add flour, water, and raisins. Add yeast at some point.
Cover and set to rise between 1 1/2 to 2 hour (until dough triples in size).
Turn dough out on a floured board and divide into 4 parts.To braid, divide each part into 4 smaller sections. Braid 3. Divide the remaining part in 3 and braid.Place the smaller braid on top of the larger braid.Repeat for the other 3 challahs.
Put into 4 pans and brush tops with saved egg mixture.
Cover and set at room temperature to rise until it reaches over the top of the pan.