+1 for both ph mention and t shirt or cotton cloth.:D
i would recommend using a 1-2 gallon continuous brew method to grow you scoby nice and thick before taking on a five gallon brew. one and a half gallon glass jars work great as well if you want to stick with single batches. just remember...
ive heard this too. my dog has gotten into hops before and i was really worried but he ended up[ turning out just fine. of course he has also eaten glass, so.....
if you do go this route you need to make sure that you have a highly alcohol tolerant yeast in order to prevent the alcohol content from stoping the small amount of fermentation that is going to produce your all so elusive co2