I have been making my starters without a stir plate, check out the graphic that was given to me when I first started making starters. I used 600ml of water, and 60gm of DME in my 1000 ml flask, once the starter is finished I merely keep it in a 70 degree environment, and swirl the flask when I walk by. My son has the warmest room in the house, and he stays up playing games late night so I put it in his room and told him to swirl it periodically during the night. It worked awesome, I'm cold crashing it over night, then tomorrow in the AM I will take it out, pour off 80% of the liquid (now beer) let come to room temp for pitching in my brew tomorrow in morning.