I am making a belgian dubbel and using wlp500 trappist yeast for it. I made a 2l starter(my 4th) exactly the same as all the others I have made. Unlike all the others 24hours on a stirplate and i have nothing. Bad vial of yeast? Or is wlp500 slow to get going?
Stop your stirplate and let the yeast settle. I bet it's there. WLP500 doesn't seem to foam up a lot for me. Some yeast are faster than others. I usually try to make my starters 3-4 days before I brew, with the last day in the fridge.