There's no nonstop path connecting Palm Beach International to Sofia, which means every business class from West Palm Beach to Sofia itinerary routes through at least one major European or East Coast hub, and after flying this corridor repeatedly, I've come to appreciate the routing options more than resent them. Delta typically funnels passengers through JFK or Amsterdam, pairing a domestic hop with a transatlantic leg in Delta One suites—sliding doors, direct aisle access, and a product that holds up admirably over the roughly 11.5-hour total journey. Lufthansa's preferred connection runs through Frankfurt or Munich, where their long-haul business class (and increasingly the new Allegris cabin on select aircraft) offers a genuinely restful lie-flat experience before the short Star Alliance hop down to Sofia on a regional jet. Bulgaria Air, the national carrier, doesn't operate widebody service from the US, but it's worth booking for the intra-European leg if you want a seamless single-PNR itinerary with Lufthansa or Star Alliance partners.
My strong preference on this routing is Frankfurt over JFK for the connection: Lufthansa's FRA hub has more frequent, better-timed flights to Sofia and a shorter minimum connection time, which matters enormously after a red-eye. One insider tip few travelers know—flying into Munich rather than Frankfurt when Lufthansa offers it can shave real time off immigration and security requeue, since Munich's Star Alliance connections are less congested during peak morning banks. Seasonally, this route behaves like most transatlantic US-Europe corridors: deep winter (January, February) and shoulder months (March, October, November) reliably produce the softest business class fares, as Bulgarian leisure demand dips outside summer and the Christmas markets rush.
Given how thin premium inventory can get between PBI and SOF—especially on Delta One and Lufthansa's newest cabins—travelers serious about this route should be tracking fares continuously rather than checking sporadically, since award and discounted business seats here tend to surface briefly and disappear fast.
