Too much yeast possible?

Cider
1

I am going to be trying out a few different yeasts this weekend in one gallon batches with a store bought pasteurized cider. Is it possible to have to much yeast if I just put the entire packet in or should I take a proportional amount out of the packet/tube. The yeasts I am trying are

EC-1118
and
White Labs English Ale

I figure if I add some brown sugar to the WL Eng Ale I will end up with a slightly sweet cider. I am just experimenting. I have only brewed a couple of batches prior to these. They will be sitting at a constant 64 degrees in my basement.

2

It is possible to use too much yeast. For 1-gallon batches, I’d use no more than half the yeast in each. Too much yeast can give different flavors. It would still make cider, and it wouldn’t make it bad, but it wouldn’t really give you a good idea of what those yeasts would do in a full batch. For the liquid yeast, just pour 1/3 or 1/2 of the pouch in. For the dry, you could rehydrate the yeast and then pour half of that in, or just pour 1/2 the packet.