Ponder the TV dinner cranberry sauce – yes, there is a patent for that.

Ponder the TV dinner cranberry sauce – yes, there is a patent for that.

Image from vintage Swanson's TV frozen dinner ad showing cranberry sauce

Tinfoil & frozen slabs of food.

Ever lay in bed wondering about something and become obsessed with it? Over the past weekend, for reasons that admittedly mystify me, I became obsessed with the little cranberry slots in frozen tv dinners. You know that scoop of jellied red stuff that comes with frozen turkey dinners? It’s supposed to be cranberry sauce. What I began to wonder is, why doesn’t it turn into a pile of liquid goo when it’s heated in the oven? Why doesn’t it melt?  Guess what? There’s a patent for that, plus some mad cooking chemistry.

“Cranberry sauce is now so widely recognized as an almost indispensable accompaniment of any turkey dinner, that it is sorely missed when omitted from frozen turkey TV dinners.”
1964 Patent filing Ocean Spray

Ocean Spray was right, turkey dinners aren’t complete without cranberries. It’s big, big business. I can’t even envision Thanksgiving without a big dose of cranberry sauce. Adding a little tray of it to a tv dinner would be a strong selling point. Scoff at such an invention as cranberry sauce that maintains its form after being frozen & then heated, but it boils down to marketing dollars.

To Google Patent Search!

Of course, my first stop was a quick search of patents and there it was – the magic behind solidified cranberry sauce, courtesy of Ocean Spray, the cranberry behemoth in the US. They filed a patent for that tiny bit of red stuff in 1964 titled METHOD OF MAKING FROZEN DINNER CRANBERRY COMPONENT, United States Patent 73,360,385 granted 1969.

“A method for maintaining cranberry sauce in a gelled state upon thawing of a frozen TV dinner, comprising adding an acid tolerant, quick acting freeze surviving vegetable gelling agent such as hot hydrated starch to cooked cranberries, adding a sugar syrup, cooking the mix to form a sauce, placing an individual serving of the cooked sauce in the TV dinner package and subjecting the contents to a freezing environment to freeze said sauce.”
Patent filing Sept. 9, 1964, Ser. No. 395,323

Now, here’s the problem tv dinner makers faced with cranberry sauce – it wasn’t friendly to freezing.  It also wasn’t friendly to being made in large quantities. When manufacturers tried, they were left with “packages … on thawing, in an un-gelled flowing liquid so unfamiliar as to be unacceptable to the consumer” [r/f Patent]. Such a mess was unappetizing to the average consumer. So, they were faced with the conundrum of how to make cranberry sauce on a large scale, have it freeze and bake while maintaining a shape and consistency acceptable to the public – but still be cost effective.

Troubles with cranberry sauce stabilization.

An interesting issue subsequently cropped up, even after a stabilized product was made – the mechanized process of dropping the sauce onto the tv tray broke down the gelled status, creating the same problem. Something in the mechanical pumping system caused the problem.  The option of having the cranberries scooped onto the tray by hand was discarded. It was far too time consuming and labour intensive to be profitable.

So that left them with the same problem – how to get cranberries onto the tray quickly and still have it recognisable.  The solution lay in cooking chemistry. After experimenting, Ocean spray produced this mixture:

  • 500 pounds of cranberries
  • 30 pounds waxy corn starch to act as a gelling agent
  • 60 pounds of sugar syrup
  • 30 gallons of water.

The cranberries were cooked down in 25 gallons of water (at around 190F) and then strained.  The starch was mixed to the remaining water and heated to 190 F and then added to the cranberries. The syrup was immediately added and cooked until the mix reached an acceptable consistency. The sauce could then be piped directly onto the trays while hot and sent off to be quick frozen. When Ocean Spray popped the dinners into an oven, the cranberry sauce remained in a gelled state and didn’t “contaminate” the rest of the foods. And the rest is marketing history – turkey dinners complete with a little compartment of cranberries.

That’s interesting chemistry at work – you need just enough gelling agent and the right temperature to obtain optimal jelly status on an industrial scale. What’s not to love about that little blob of gelled cranberry sauce that is impervious to mechanical insertion, heat and freezing?

One thing that comes to mind is, has the recipe been altered now that that the dinners are on microwavable cardboard trays? Did they have to alter the recipe? Does microwaving effect the formula? Something to look consider.


Read the original patent here – Method for making frozen dinner cranberry component

Vintage ad for Swanson TV dinner with Turkey and cranberry sauce

Does Swanson still make this?

Check out my newest cranberry related patent.

Holidays, cranberries & 1 patent to put ridges on the jelly