Today I made AG#26. Much the same as many previous brews and with a healthy efficiency. Just not as healthy as I often achieve. I heated the water to the usual temp. for a BIAB, which with my equipment if 68C. When I'd added my grains it only reached 65C.I often find it dropping very little below 68C and maintaining at least 64C after 90 minutes. Today it fell to 62C at the end. I'm guessing that my 4-5% lower efficiency was caused by this lower mash temp. I must have fannied around with the lid off for too long.
Do AG brewers find that their efficiency alters with different mashing temperatures?
Do AG brewers find that their efficiency alters with different mashing temperatures?