I have been unable to verify this assertion, although Amaretto clearly is associated in some way with the world's oldest republic.
According to Wikipedia, Amaretto originated in Saronno – a town in Lombardy, in the far north of Italy. On its Saronno page, Wikipedia tells us that "the place is well known for its almond kernel biscuits (amaretti) and liqueur (amaretto), and is also a manufacturing town." Wikipedia makes no mention of San Marino on either of these pages.
When I googled "amoretto san marino", I found several links to "Amaretto di San Marino". None of these however claimed that the liqueur was actually produced in San Marino; indeed one advertised "an old presentation bottle of San Marino Amaretto from Saronno, Italy".
Returning to Wikipedia, I noticed that on its Amaretto (disambiguation) page, the free encyclopedia provides a link to Amaro (liqueur), one style of which is made in San Marino. But Amaro "should not be confused with Amaretto".
It seems to me that someone, somewhere, may have got confused.
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