Well I know I'm bad but I wasn't aware I was this bad... My latest brew session has some strange results for Efficiency and I don't believe it. I have no idea why the system is saying this though. Answers please as it has me stumped... Summary of recipe: Now the only thing I may have got wrong is the setting for Mash Thickness. The listed value as listed was from a previous brew. The actual thickness was 4.6 litres/kg. This time round I used one single mash volume at 28 litres and 2 litres as a "sparge" amount but actually used that as top up before the boil. Fermentables are there - both with a DP value.