Made this after reading this thread through. First off, the recipe corrections have been made in the second printing of the book so no need to check the errata page. I was concerned about the burning/adding water issue but had no problems, in fact the opposite!
I was making only a half recipe so added only 40g of butter and no water. Brought the cooker quickly to pressure and then turned the heat down low (I have an induction hob so the heat reduces almost instantly) and after 20 minutes there was plenty of liquid but not a lot of caramelisation. I took it back up to pressure and cooked for another five minutes which gave a medium caramelisation. So the trick here seems to be getting the heat right after the pressure has been obtained.
One other observation is that the recipe states that 635g of carrot juice can be obatined from 700g of carrots. Not from my carrots! I have a juicer that produces a pretty dry pulp but even so I could manage only 360g of juice from 700g of carrots. Maybe you need fresh pulled carrots for this rather than cheapo supermarket ones that have probably been in the store for three weeks?
The result was amazing. Superb caramel flavour and an incredible sweetness despite using the cheapest carrots I could find (65p a kilo). I have never found that elusive 'sweetness' of shop bought carrots despite using stove top recipes that usually call for a spoonful of sugar to be added. This tasted like half a pound of sugar had been added despite there being none!
I spent ages chopping the ginger finely and it gave the perfect 'zing' every now and then when catching a piece. There was no problem with the texture when cut so finely. It occurs to me that this might work well and look good with a ribbon of ginger gel laid across the foam and soup or perhaps centred tagliatelle style. Only needs the one ribbon per dish though, anyone got any ideas what I might do with the rest of a sheet of ginger gel?