Ketchup foam

[Anonymous Modernist 12390]

Hi all, and thanks for advice/thoughts in advance.

I am planning a starter for a New Year Dinner party (each member of the family is contributing a course each). Being proudly resident in Scotland (although not native!) I am planning an unusual take on Haggis and Neeps. I've been practising my haggis gyoza/potstickers and they are turning out quite well.

What I would like advice on is my accompaniments - I would like to create a foam based on HP/brown sauce - for non-UK readers this is a fruity/spicy/vinegary sauce which is very similar in consistency to tomato ketchup - maybe slightly thinner. In Edinburgh fast food joints, "sauce" is brown sauce diluted with water and/or vinegar. I want to try and create a foam with this kind of flavour.

Has anyone had any experience of creating a foam with e.g. tomato ketchup (which I would expect to behave fairly similarly) or have any thoughts on the need for additives (e.g. lecithin). I have a Mosa cream whipper.

Thanks a lot,

Richard