Heinz 57.

Food Genuinely the first occasion when I heard the phrase "Heinz 57" was in relation to a mongrel dog which a friend of a friend of the family owned when I was much, much younger. It's not until later, in a supermarket filled with products covered with the wording that I realised the connection and where the phrase originated.

 In an idle moment, I thought I'd check what those 57 varieties are.

Snopes suggests that there never were 57 varieties but that Henry Heinz saw an advert on the side of a train for a company offering 21 different types of shoe:

"... struck by the concept, and recognizing that catchiness and Heinz resonance were far more important qualities for a company slogan than literal accuracy, Heinz cast about for the perfect number to use for his own company’s version of the phrase. Settling on fifty-seven, Heinz soon put the number to work, and within a week the sign of the green Heinz pickle bearing the words “57 Varieties” was everywhere Heinz “could find a place to stick it.” He soon ordered the construction of a six-story, twelve-hundred-light display featuring a forty-foot pickle; installed at the intersection of 5th Avenue and 23rd Street in New York City, this electric marvel dazzled New York residents and tourists until 1906."

But this Wikipedia page randomly includes, without explanation, a section called 1934 cookbook products which lists what the 57 varieties might have been:

"Heinz Oven-Baked Beans – Pork and Tomato Sauce
Heinz Oven-Baked Beans – Pork no Tomato Sauce
Heinz Oven-Baked Beans – Tomato Sauce no Pork
Heinz Oven-Baked Red Kidney Beans
Heinz Cream of Asparagus Soup

Et cetera. Drilling down into the reference section reveals they're taken from the The Heinz Book of Meat Cookery, a photo of which can be seen on this ebay entry, presumably to add some authenticity to the claim.  Sadly most of those products are no longer in production.  Although as Snopes says, Heinz now produce over a thousand products, so you can pick and choose which once you'd like to include.

Which answers my question.  There never were just 57 Heinz varieties.  Except there were.  Sort of.