Keep Refrigerated (maple syrup, corn syrup)

[ChrisGreaves]

Up here in The Frozen North we have nutrition & disclaimer labels on everything.
The glass bottle of maple syrup reads "Keep refrigerated" and I wonder why.
My understanding is/was that bacteria can't survive in strong sugar contents, such as Maple Syrup, Corn Syrup⁽¹⁾, Honey etc.

Is this warning "Keep Refrigerated" on the maple syrup just because the firm's lawyers like keeping the board of directors in a perpetual state of fear of lawsuits?

⁽¹⁾ I know they do maple syrup in Maine⁽²⁾, but we tend to think of Corn Syrup as coming from South Of The Border.

⁽²⁾ I knew a guy once who says he was drinking with a guy who said that HE had seen a bumper sticker that read "Welcome to Maine; now go home!"

[HansV]

Pure maple syrup is a tree sap. It can be kept almost indefinitely in an unopened container, but once the container has been opened, you should refrigerate it to prevent mold from developing.
Corn syrup and honey, on the other hand, don't need to be refrigerated after opening. It's very unlikely that they would become moldy, and they become difficult to use at low temperatures.

[Rudi]

I never put any syrup forms in the fridge. As Hans mentioned, it becomes a sticky hard blob and not easy to use. Our syrups and honeys either come in a tin with a pop off lid, or in a plastic bottle with a nozzle head and pop off lid. Once I have used it, the lid goes back on and its into the kitchen cupboard. I cannot recall any of our syrups indicating that it needs to be refrigerated.

[ChrisGreaves]

Pure maple syrup is a tree sap. It can be kept almost indefinitely in an unopened container, but once the container has been opened, you should refrigerate it to prevent mold from developing.
Corn syrup and honey, on the other hand, don't need to be refrigerated after opening. It's very unlikely that they would become moldy, and they become difficult to use at low temperatures.

ER, Right!
But, but ...

Maple Syrup, as made oop north is practically pure sugar; if you dry it out a bit more you get cakes of maple sugar.
So just like corn syrup, it ought to be immune 9sort of) from mould or other nasties, no?

Hans, are you suggesting that maple syrup is quite a different thing from corn syrup? To my mind they are both syrups of sugar compounds.

FWIW we never used to refrigerate the Tate & Lyle syrup (or treacle) in even the hottest weather in Australia.

[HansV]

If you do a Google search for store maple syrup, you'll see that the general recommendation is to refrigerate it once opened.

[mishmish3000]

I've always refrigerated syrup after opening it. It would definitely cut down on the likelihood of critters growing inside it (seems like warm syrup would be a great growth medium, but I'm not a microbiologist. I just know some.)