I have heard of yeasts having killer properties towards other different strains.
Im shortly about to put a 2 canner on.. one coopers bitter plus one draught
also add 1kg dextrose, plus some cascade hops, for about 25 lt total.
You buggered it up. Thought I would get all of the posts.8)
Anyhow, all home brewers underpitch to a degree. One pack, two packs isn't a logarithmic change in rate.
Won't make a difference in a two-can brew.