ok it's my second attempt at homebrewing the first batch came out fine the second batch i used a different recipe the first time i cooled the batch down to 70 degrees before pitching the yeast the second time the instructions simply said to let it cool to almost room temp i waited hours and around midnight i pitched the yeast i really don't know what temp it was i'm guessing 90-100????? in the morning it had blown the lid off just on one side i cleaned it up and resealed it now i've learned that i may have killed the yeast any thoughts???? can i re pitch the yeast???? will a gravity reading tell me if it fermented???