Korean Air Skypass - Can I get in KE lounge early

I'll be flying from DC-JFK-INC in business this weekend with a near 5 hour layover at JFK. The lounge there opens at 9:00PM, 4 hours before my KE flight. Will they let me in the lounge then? I noticed online that it says lounges are available 2.5 hours before a flight. I hate the idea of sitting around for an hour and a half waiting for access to the lounge.

If landside, you can probably get DL (presumably your carrier for DC-JFK) to issue your BP for JFK-ICN in Business. That ought to be enough to get you into the lounge, which is most likely a shared one with AF (whose flights to Europe leave earlier, meaning the lounge would be open earlier). Someone else will have to say for sure which lounge KE uses.

This would work especially well if the lounge KE uses is landside in Terminal 1 rather than airside. If landside, you can just duck out to the checkin desk and get KE to check you in for your ICN flight, then duck back in. If it's airside, you'd have the hassle of security between you and the checkin desk. OTOH, you could stay airside and just get a new BP from the gate agent when the gate opens. FWIW, even if DL issues you a BP for JFK-ICN, I always recommend getting a new BP from the operating carrier.

If all else looks like it won't work, you can try using your KE Business Class BP to get into the Crown Room in Delta's Terminals 2 or 3 (depending on which you arrive at). As a SkyTeam partner of KE, DL probably would let you in, especially if you explain that you just arrived on DL and you're waiting for the KE checkin desk to open.

You have 2 alternative choices at JFK.

Terminal 4 has Skyteam lounge called "Oasis" lounge for all Skyteam flyers.
-This lounge is out side of security check.
-Has food all day, greater variety of snacks.

Terminal 2/3 has DL Crown Room and BE lounges.
-Inside security
-CRC has no food, only snacks.
-BE lounge has food starting around 4 PM.

I saw on the SkyTeam website that the Air France and Alitalia lounges in Terminal 1 (used by Korean Air) are both airside.

KE's JFK lounge is actually on airside. :( So you'll have to not only go through security but also exchange your DL-issued boarding pass to KE ones. I tried going straight to the lounge with such boarding pass, but failed. :/

Therefore, you can get into the lounge as early as the KE counter opens. :)