I was flying Korean Air Prestige Class, their Business Class, from Singapore (SIN) to Seoul Incheon (ICN). Because Korean Air does not have lounges at Singapore Changi Airport Terminal 4, they contract with the Blossom SATS and Plaza Premium Lounge for premium class passengers. 

The Blossom SATS and Plaza Premium Lounge are better than I expected regarding food and seats. Here's a detailed review:

Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
Blossom SATS and Plaza Premium Lounge
Table of Contents  [show/hide]

    Location

    The easiest way to find Blossom SATS and Plaza Premium Lounge at Singapore Changi Airport Terminal 4 is to note that after clearing immigration and security, follow the sign for "lounges" and get up to the escalator. While you are standing upstairs looking at the signboard, there's no mention of the Blossom Lounge. However, just continue walking past the Cathay Pacific Lounge, and you will soon see the Blossom Lounge. 

    Access

    Flying Business Class or Prestige Class with Korean Air, you are provided a lounge invitation card to show to the lounge staff with your boarding pass to enter the lounge for free. 

    It's worth mentioning also the lounge also participates with the Priority Pass under the Blossom Lounge name in Terminal 4 at Singapore Changi Airport, so ultimately, you can access the lounge using your Priority Pass Membership too!

    Price

    I asked and was told 3 hours for SGD 55. 

    There are three names associated with this lounge because of the partnership. The lounge's name is Blossom, and it partners with SATS and Plaza Premium Lounges

    Seats

    I'm impressed by the seats and layout of the Blossom SATS and Plaza Premium Lounge. It wasn't crowded when I was there, and the seats are nicely padded and look comfortable.

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Blossom Lounge Seats

    The cubical seats offer privacy, which reminds me of a premium-class cabin on a plane. You can snooze in there if you can sleep in a semi-recline position.

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Cubical Seats

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Semi-Reclining Seat

    The dining seats are also plenty to enjoy around the buffet station.

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Dining Seats

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Dining Seats

    There are also seats with an ottoman to put your feet on and relax to enjoy the animation display.

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Animation Display

    Most seats also come with a power outlet and USB charger. Except for the cubicle ones! 

    Overall, the seats are comfortable and very nice in the lounge. I'm impressed! 

    Food

    Food is another area that shines at Blossom SATS and Plaza Premium Lounge

    They have a salad bar, a pastries bar, and hot food such as Indonesian chicken, fried fish, rice, and vegetables. 

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Salad Bar

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Noodles Bar

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Hot Food Buffet

    Then there's also a noodle bar that offers Singapore laksa and vegetarian soup. I specifically love the laksa there, but I had to keep my stomach for dining in the sky with Korean Air later on in Prestige Class. 

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Laksa & A Beer

    Drinks

    There's a bar, but unfortunately, it looks like they were short staff, so the bar was closed when I was there. However, if you want a draft beer, the lounge staff could get one for you, and there's also unlimited liquor by the drinking station, so you can make your own cocktails!

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    The Bar

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Unlimited Liquor Station

    Bathroom

    The bathroom is not bad, not the cleanest, but not bad. The toilets have high panel doors that offer a bit of privacy. 

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Bathroom

    Massage Chair

    There's a massage chair inside the Blossom SATS and Plaza Premium Lounge. However, it's not free or complimentary for lounge guests, and it is a pay-per-use service. 

    Review: Blossom SATS and Plaza Premium Lounge Terminal 4 at Singapore Changi Airport (SIN) For Korean Air Prestige Business Class
    Massage Chair

    Wi-Fi 

    Blossom SATS and Plaza Premium Lounge have their own Wi-Fi and password required, but connecting to the free Changi Airport Wi-Fi was sufficient for me. 

    Conclusion

    Korean Air has no lounge at Singapore Changi Airport Terminal 4 for Business Class or Prestige Class passengers. They contract with the Blossom SATS and Plaza Premium Lounge, and the lounge is quite impressive with its comfortable seats and privacy. The buffet food is also good. While the bar was closed, you could still serve yourself with unlimited alcoholic beverages at the drinking station.