IMO the variance from predicted FG in a normal range is about .003 +/-. So what I would expect as a FG for a prediction of 1.016 would be anywhere between 1.019 to 1.013. Usually it is closer but I don't get concerned until well outside this range. You are just outside that range. The low mash temperature could be the culprit. The chance you notice much, unless you are have a very discerning taste, is not likely. Maybe just a tiny bit.
I have seen it reported and also experienced that if you re-use yeast, either from the last batch very fresh, or make a starter from a previous batch, the next generation will attenuate a little more than the first. Energized? healthy yeast? I don't know but it happens.
I have seen it reported and also experienced that if you re-use yeast, either from the last batch very fresh, or make a starter from a previous batch, the next generation will attenuate a little more than the first. Energized? healthy yeast? I don't know but it happens.