This Union Square Ramen Shop Slings Pure Ocean Umami Until 3:30 a.m.

The Midnight Diners is a regular collaboration between KQED food editor Luke Tsai and graphic novelist Thien Pham. Follow them each week as they explore the hot pot restaurants, taco carts and 24-hour casino buffets that make up the Bay Area’s after-hours dining scene.

At 11 o’clock on a recent Friday night, the busiest restaurant in Union Square wasn’t a pizza joint or all-night diner, but instead a tiny ramen shop specializing in a relatively undersung, niche soup style. That about sums up San Francisco food culture in a nutshell.

The noodle shop in question is Hinodeya Ramen, which first brought its vaunted dashi ramen to San Francisco from Japan’s Saitama prefecture in 2016. Its owners made the bold move of opening a new late-night Union Square outpost in 2022 — in the thick of the pandemic, when the vibes downtown were perhaps at their lowest point. It’s one of just a small handful of restaurants in the neighborhood that are open past midnight. In fact, on weekends you can still get a bowl of steaming-hot ramen as late as 3:30 a.m.

Of course thousands of words have been written about downtown San Francisco’s retail apocalypse and the slow-simmering demise of Union Square. But at least within the tight, noisy confines of this pint-sized ramen restaurant, you would never guess any of that. During the entirety of our visit, the dining room was filled to capacity — more than 30 ramen eaters crammed practically shoulder to shoulder — with what looked to be an equal mix of SF locals and tourists. At the table next to us: a smiley college-age Latino couple on a date. A few tables down: a big, multi-generational Asian American family, including an 80-plus-year-old grandma with her face mask pulled down for ease of slurping.

Our server told us they get one big rush of customers from around 10 p.m. to midnight, and then another at 2 a.m., when the bars let out. Everyone seemed to be having a good time.

You may have heard that in Japan, ramen is considered fast food, which isn’t a statement on quality but a matter of pure speed and accessibility. Hinodeya stays true to that spirit: Even though there were five or six parties ahead of us in line when we first stepped through the restaurant’s curtained doorway at a little past 10 o’clock, we were seated within minutes. The food also came out in a flash, just minutes after I buzzed in our QR code orders on my phone.

In comparison to other top ramen shops, the noodles, chashu, soft-boiled egg and other toppings at Hinodeya are all perfectly adequate. But the shop’s be-all end-all is its dashi broth — especially for ramen enthusiasts tired of the thick, creamy, extra fatty tonkotsu style that’s so pervasive in the Bay Area. Instead of just boiling bones to smithereens, the basis of Hinodeya’s standard house ramen is a relatively light, clear soup that’s all balance and nuance, oriented around the umami of the sea: kombu, bonito flakes and scallop bouillon. The dried scallop, in particular, gives the broth an incredible depth of oceanic flavor, and a touch of pork fat adds just the right amount of luxurious richness.

The dashi broth is low-key one of my favorite ramen broths in the Bay; it’s the kind of soup I could slurp down once or twice a week without ever getting tired of it. It feels frankly preposterous to have access to something this good, served this quickly, at 2 or 3 in the morning — right smack in the middle of Union Square, no less.

Hinodeya also offers a bunch of special ramens, available in limited quantities, like a sukiyaki beef ramen and a ramen topped with fried pork cutlet. And so the other nice thing about the Union Square shop is that, at least during our visit, all of the specials were still available even at 11 p.m. In keeping with the ocean umami theme, we went with the shop’s other signature dish, the hamaguri ramen, which comes topped with a couple dozen sweet littleneck clams in their shells. Here, Hinodeya’s standard dashi soup gets doctored up with a hit of fresh garlic and, of course, all of the clams’ briny juices. This is the ramen for you if you’re a linguine alle vongole lover — if your favorite part of an order of steamed Quahogs is sipping the clam liquor at the bottom of the bowl.

The non-ramen dishes at Hinodeya are equally well calibrated for late-night enjoyment, like the juicy, crisp-bottomed gyoza, which come with a side of salty concentrated dashi broth — the ideal dipping sauce, it turns out. If you’re feeling extra hungry, you can finish off the meal with a big ol’ bowl of rice. We opted for the gyudon, a hearty rice bowl that comes topped with thin slices of tender, soy-sauce-simmered beef and a runny-yolked poached egg. But plain white rice would also hit the spot, especially for connoisseurs who know the pleasures of using rice to soak up the last dregs of your leftover ramen broth.

We saved just enough room for one last, not-too-sweet bite for dessert: a little square bowl of jello-like matcha pudding topped with a dollop of whipped cream. And just like that, about an hour after we sat down, even having taken our time, we were back out on the street, our bellies full, the taste of the ocean on our tongues. Up above us, the glittering lights of the big Union Square hotels shined just as brightly as they ever did.

Hinodeya Ramen’s Union Square location is open 10 a.m.–3:30 a.m. Fridays and Saturdays and 10 a.m.–1:30 p.m. the rest of the week at 219 O’Farrell St. in San Francisco. The restaurant also has locations in Japantown, the Financial District, Newark and San Jose.