Brian Arthur

This would be all well and good, if it were true, sugar goes through much higher temperatures than 60°C (140°F in ancient units) several times during the refining process. For other syrups, especially fruit syrups, the temperature can make a difference, but not for simple syrup.
Also, rich simple syrup doesn’t have to be raised to high temperatures. Magnetic stirrers used be quite expensive, so much so that labs would often make their own using used CPU fans, but that is no longer the cas.

No Malmsey here either. I used Bual, Campari, and Booth's. The Bual Madeira was certainly sweet enough, but I'd cut down its proportion a little next time. A decent drink, but not as good as the very similar East India Negroni.

I had been making this with Del Maguey Vida, which is one of only two available locally, but managed to get a bottle of the Del Maguey Chichicapa that is called for in Joaquín Simó’s original recipe. The latter was marginally better, very similar. Both made for an excellent drink.

I usually make this with Evan Williams white label (Bottled in Bond). It is an inexpensive bourbon that I buy by the half US gallon and it is my go-to cocktail bourbon. The Maker's 46 definitely ups it by half a star. I think Maker's 46 cask strength would be even better, but you are then getting into Single Malt price range. Sam, himself called for a short, gentle shake, and I have been stirring recently.