I have been doing all grain brewing for a long time, and I have a problem that has me stumped. By the way I do brew in a bag method. I have been making the same brews for ages but something has changed. Example, up until lately I start my mash at 67c, and mash for 60 min. I boil for 60 min., and I usually end up with a SG of around 1060. Over the past few brew days I have ended up with a SG of 1050. The grain bill is exactly the same, mash temp and time is exactly the same, but the SG is down 10 points. I have had the same thing happen with some of my other brews also. I use different mash temps for different brews but am having the same drop at the end of the boil. The grain doesn't sit around for very long before I use it and I also mill my grain. Any ideas why this is happening????? Kieran.