For Ray, was blue berry mead/ref. Camdon tablet

**5)  I recommend that you consider adding 50 ppm (1 Campden tablet/gal) at
the start of fermentation anyway.   Virtually all of this will be gone by
the time you bottle, which is what you want, but it will protect the mead
during primary when air is in contact with the mead.**

If I add it at the start of fermentation, won't this kill a lot of the active yeast?