I made an Austin's Oatmeal Stout on Sat, and pitched a White Labs English Ale yeast. All my temps were in range and sanitization was done to everything touching the wort after boil. It's been three days with no activity. Just took a reading. Gravity is still 1.053 (the same as my SG on Sat.). The one thing I did notice is that it looks like it was starting to form an infection on the top.
I have a US-05 dry packet in the fridge. If I pitch, will it affect the taste of the stout due to it being a differrent yeast strain?