ade1865 wrote:well looks like i may have nearly missed the boat. i'll do it tomorrow, but the brew is just about done i think. what may be the adverse affects?
I have never diluted so late, so I cannot comment upon what may or may not happen. Bear in mind though, that India Pale Ale was diluted before consumption by the overseas troops.
Personally, I'd be reluctant to bung in 8 litres at this stage, because it will probably continue to attenuate further. Instead, I would look at things back to front, as if it hadn't yet fermented. OK, you achieved 15 litres 1058. Let's imagine that you'd hoped for 1045...
58 x 15 = 870 divided by 45 = 19.33 litres.
On this basis you would add 4.33 litres. Your current gravity is 1018 so...
18 x 15 = 270 divided by 19.33 = 13.96, so your new (final) gravity would be 1013.96, or 1014, which could drop a little further.
If you do choose to dilute, use cooled boiled water rather than straight out of the tap.
Make a point of calibrating your fermenter when it eventually becomes empty. I have 4 of the Youngs type with the 4" burgundy lids and handles, and the factory calibrations are way out. 23 litres is 1/2" beneath the protruding ridge at the top of the fermenter; hence some distance above the indicated 25 litres
