Hi, I recently created a starter with equal parts flour, water, and perhaps mistakenly 1 tsp of yeast.  It's been fed with a ratio of 1:5:5 every 12-24 hours, and is only seven days old.  On the last feed, it roughly doubled after 12 hours and I put it in the fridge until needed.  My question is, is this a bad starter because I added yeast?  Should I throw it away, and start over with only equal weights whole wheat/rye flour and water? 

Thanks