I would not focus on water being a primary issue. First thing to check is to make sure your thermometer is calibrated. You can do this by sticking it in ice with a little water to to get a freezing point of 0C and then in boiling water to get a 100C reading. A few tenths off is not a big deal, but a few degrees may be a larger issue when it comes to mashing.
Havent calibrated it no. but i will get onto this today
65C to 68C is the lower to middle range of the activity range for the amylase enzymes needed to reduce the starches into fermentable sugars. If you are reading higher than actual, it would mean that you are actually in the lower range of activity which favors higher fermentability and therefore greater attenuation of the wort.
OK. im using the temp range as per beersmith, actual mash temps according to beersmith program are 68.9 for full body and 66.7 for medium body. again i'll check that thermometer and see how accurate it is
I guess the next question is where are some of your recipes starting out for OG and where do they finish for FG? Please be specific and give several examples. Are you using any simple sugars in your recipes?
i will get some examples and put them in a new post. no simple sugars, grain only
You give your efficiency as around 70%, this is for mash efficiency? or is that the brew house efficiency? Since brew house efficiency has other process losses, it really does not tell us anything, but your mash efficiency will tell us how well you are converting and removing the sugars from the grist. Too high of a mash/lauter efficiency can sometimes give you higher fermentable wort, though this is more common with over sparging than with a full volume BIAB.
yes mash efficiency.
Lastly, from where and who are you getting the feedback on the low body? How do you feel about the body of your beers? Do they meet your expectation or are they thin and watery to you?
ok so low body feedback is from, mates with 20 plus years of experience brewing, 2 pro brewers, and homebrew comp judging notes. i agree with the feedback as i would like a fuller bodied beer but just cant get there