I attempted BIAB for the first time today, going from extract brewing. It did NOT go well. I was trying to make this: http://www.homebrewtalk.com/f78/holl...as-ale-145580/
My pre-boil efficiency came out to be around 57%, unfortunately. I have two theories based on what I observed today.
1. Bag Size: I used a 5 gallon paint strainer from Lowe's, which seems to be the norm around here. I think this brew was a little too big for this bag. First of all, I discovered that bag's mouth does not cover the opening of the kettle. In fact, I could only stretch it across about half way. So because of this, I added the grain to the bad OUTSIDE of the kettle. In hindsight, this prevented me from adding a little bit slowly and stirring as I pour in the grain. Also, because the bag was so full I think it was packed a little too tightly. This prevented the water from really getting in there.
2. Mash Temp: Because I added all the grain at once, the water didn't slowly get to the right temp. I got the strike temp to about 160 and tried to stir as best I could. But 30 minutes into the mash, I checked and the temp was around 142. I immediately heated back up and I added some time to the mash. I did wrap the kettle in blankets. I don't think I necessarily LOST that much heat, but my strike temp wasn't initially high enough and after I added the grain it was packed so tightly that it didn't immediately drop the temp down a lot, but as water got into the grain it brought it down more than expected.
I think overall 1 was more of an issue than 2, but both definitely played a part.
I added some DME and my actual OG wasn't too terribly off the target for this beer. 1.066, which is what some people in the thread for that recipe have reported when doing BIAB.
I am disappointed but I think I learned a lot. Do my guesses as to what went wrong seem possible? My biggest takeaway is that I need a larger bag (hello, http://biabbags.webs.com/
). I really should have done a smaller beer for my first...