Surry Hills, Sydney. What I Drink When ... and will feature one of the Umbilical brothers, David Collins. Photo: Quentin Jones. 24 April 2012.

Glass act ... funny man Collins likes brandy - in this case, a Horse's Neck. Photo: Quentin Jones

David Collins sips a brandy and ginger ale concoction in a tall glass in the public bar of Surry Hills' Beresford Hotel. Then he unwinds his sinewy limbs to re-enact one of his earliest gigs as one half of the Umbilical Brothers, miming a violent end to the Brady Bunch.

It's a tour de force given Collins has just stepped off a long-haul flight from Amsterdam and is still feeling the effects of a sleeping pill. The wavy-haired performer and his bald comedy partner, Shane Dundas, who have performed clever slapstick-with-sound-effects for more than 20 years, have just toured three different shows across Europe.

Now Collins has loosened the cord from Dundas to premiere an original play at the Sydney Comedy Festival with a different performer, Paul Ayre. In The Air Tonight is about two spacemen travelling to Pluto in 1989.

The spacemen's only soundtrack choice is the greatest hits of Phil Collins (no relation). The comedian groans and anxiously riffles through an annotated, unstapled script of the play that includes newly revised lines a week before opening night.

But why worry, he figures, and channels his anxiety into the Brady Bunch sketch re-enactment - a career low recalled through the brandy- and vodka-soaked mists of time.

''It was about 20 years ago and I was in Melbourne,'' he says. ''We had performed downstairs at the Last Laugh and the show was fantastic. At the time I managed to be very friendly with the manager so drinks were on the house and I was drinking vodka, lime and sodas.

''I was completely smashed - but a nice smashed; I get a nice smashed on spirits - and then they said, 'Don't forget you've got to perform upstairs tonight too'. They had a little comedy venue called Le Joke upstairs.

''It was the first and only time I've got on stage drunk and I was very drunk. But we finished and everyone was yelling for more.''

So the Brothers came back on and, while Dundas improvised The Brady Bunch theme a cappella, Collins roamed about miming the systematic slaughter of Marcia, Jan, Bobby, Cindy et al, while uttering Brady lines such as: ''It's OK, Bobby, we're not related by blood.''

Alas the mime went on for too long. Even minor characters such as housekeeper Alice's love interest Sam got butchered. The performers lost their audience's interest.

An invaluable lesson: don't drink and gig. It kills timing.

Dundas doesn't drink, so Collins jokes he feels the ''obligation as an Australian'' to make up for his comedy partner's sobriety.

These days Collins likes to order a Horse's Neck - brandy with ginger ale and a long spiral of lemon, served in a highball glass. He first drank one some years ago on tour in Japan, probably with a chicken meal, he thinks; chicken being the only meat the married father of two eats.

Collins doesn't like beer much and drinks wine if he is at home cooking. ''We do get taken a lot of places and get wined and dined, but we don't go out and destroy ourselves because it's very difficult to perform on a hangover.''

Brandy, however, ''fits into every possible temperature,'' the comedian says. ''You could drink brandy in the Serengeti or the Antarctic and still be considered classy. In any bar around the world if you ask for one you have a reasonable chance of getting a drink.''

 In the Air Tonight, Sidetrack Theatre, Marrickville, until May 20, sidetrack.com.au.