I had a quick question about the wyeast liquid yeast packets, specifically the activators. All it says on the wyeast site is that the packets contain a yeast slurry. I don't know what exactly they mean, obviously it is a packet of yeast in liquid, but is it water? (I should think it would be). So assuming it is water, my question is, is there a danger to yeast viability if the packet should be subjected to freezing temperatures? because I read that ice crystals damage yeast, so my concern is, having ordered a kit containing one of these yeast packets, should i be concerned that they it will probably sit on my porch for a few hours, when it is about 20 degrees here? Thanks in advance.