Some of the physics of water in Jet A1 at
www.facetinternational.net/pdfs/aviation/aircraft_refueling.pdf It would appear that the behaviour of water as the fuel temperature falls is understood.
Back at the AAIB report graph on page 5. (bottom rt hand corner, enlarge to 800% for a clear view) Does anyone understand why the fuel consumption from the left hand main tank increased immediately after the scavenge from the centre tank. This following 7 hours when the fuel consumption from both tanks was identical?