It was a one-off Tiswas special broadcast live from a racetrack in the Midlands (possibly Donington Park or a speedway circuit, can't quite remember). They had a giant yellow custard pie - basically a really big outdoor, blow-up swimming pool, filled to the brim with classic Tiswas shaving foam coloured yellow. Of course, at the end of the show everyone got pushed into it, which is where this pic is from I think. It was about chest deep! One of the most exciting Tiswas shows I ever saw because of the giant pie - even at the age of 14 or whatever I was, I wanted to jump into it with them... so awesome and frustrating at the same time because it seemed so unachievable!! Doubt whether any footage exists... but I've seen more still pics like this.
I seem to remember, in the dim and distant past, a particular filmed insert in Tiswas. Sally James was doing a custard pie test using the least realistic ingredients possible (mashed potato, beaten egg whites etc). Then suddenly she said these were nowhere near as good as the usual pies and jumped into a giant shaving foam pie. The give away was the Gillette factory in the background. Some lucky employees joined her in the pie. I think Gillette even got a credit.
I seem to remember it was around 1981/1982. Sally James & the new members of the Tiswas team were having a custard pie fight outside with some other people. The Phantom Flan Flinger ran off behind a bush & the other team chased him. He then threw people into this giant pie. It looked massive & quite deep. I was about 10 or 11 & I have been looking for this scene for years. I remember it being great back then.