The 52-year-old TV presenter made the unusual revelation while discussing whether she preferred brown or red sauce - and was hailed a "culinary maverick".
Co-host Dan Walker asked: "The other most imporant question to ask you this morning is - sausage sandwich, red sauce or brown sauce?
Watch: Pennsylvania Farm Show food recipe: Pulled pork
Minchin replied: "Neither - marmalade. That's really messed with your head hasn't it?"
Walker was clearly taken aback, responding: "What? You're a maverick.
"My grandad used to have marmalade with bacon but what? Just normal marmalade? You're breaking culinary boundaries."
Weather presenter Carol Kirkwood was equally bemused, admitting: "I've never tried that. I prefer mustard."
Walker added: "What's wrong with just normal ketchup?!"
Viewers were a little taken aback by Minchin's marmalade confession.
Andrew tweeted: "You have marmalade in a sausage sandwich?????? @louiseminchin That's not right."
But several were intrigued enough to give it a try themselves - potentially starting a new craze.
Karl Bowles wrote: "@louiseminchin were you serious about marmalade on a sausage sandwich? It made me go urrrgh... but still tempted."
And Martin Chapman tweeted: "Ooh @louiseminchin I think I need to try marmalade with sausage sandwich."
zDeva even revealed she had been inspired, posting a picture captioned: "Amazing Sausage and Marmalade sandwich inspiration thanks @louiseminchin"
In 2019 Minchin revealed she was taking a step back from social media because she had had enough of the "cycle of negativity."
She wrote: "You might think I am oversensitive (I probably am), and need to grow a thicker skin (I probably do), but the truth is I can read a hundred nice comments about me but it will be the nasty one I will remember, try as I might to shrug it off.
“Recently the level of acrimony on social media reached unnerving levels, with people constantly shouting at each other, whipping up outrage and throwing around wild assumptions.
“I realised, I had had enough of reading it and being drawn into the cycle of negativity.”
Watch: Louise Minchin spot story calling her a triathlon cheat