Salty and strong, Korean soup soy sauce (guk-ganjang: 국간장 but also called joseon-ganjang: 조선간장, aka “Korean soy sauce”) is not just for soup, it’s also good for seasoning stews, meat, seafood, and vegetables. It’s very different from the commercial soy sauce you’re used to. That darker and sweeter soy sauce was invented in China and introduced to Korea through Japan, and Koreans call it jin-ganjang. It is good as a dipping sauce or a light flavoring agent, but it’s not robust enough to flavor a whole pot of soup—and it’s too dark for that anyway.

Korean soup soy sauce has a richer, more savory flavor. It is light in color, and it doesn’t change the color of a broth much, which is why it’s perfect for adding flavor to a big batch of soup without changing its appearance.

I’ve never found a commercially made guk-ganjang that satisfied me, so I don’t buy it: I substitute fish sauce if I don’t have homemade. In many of my videos you see me using fish sauce because that’s what most people have available and what I recommend they use, but in my day-to-day cooking I use my homemade guk-ganjang, if I have it.

This recipe is a by-product of making fermented soybean paste (doenjang). All you have to do is boil the soy sauce left in the jar after the bean blocks have fermented. It’s a simple step, but it does require attentiveness: Do it wrong, and the soy sauce will have an off flavor and eventually attract mold.

Some Koreans never do this step, they just use their soy sauce straight away without boiling it. They like the taste and just remove any floating mold they see. Even if you boil the soy sauce, you might find a bit of fungus growing on top of your soy sauce some day, especially if you keep it for years. Just remove it, it can’t hurt anything. Some families keep their ganjang for hundreds of years, passing it down from generation to generation! It changes as it gets older, it gets darker and the flavor deepens.


Makes about 7½ quarts

  1. Soy sauce from fermented soybean paste (doenjang)


  1. Sterilize your jars. Fill two 4-quart glass jars or one 8-quart jar (or use any number of jars as long as the total will hold 8 quarts) with boiling water and let sit for 10 minutes. Pour the water out and let containers air-dry.
  2. Place a folded piece of cheesecloth in a strainer set over a large bowl. Strain the soy sauce, leaving any solids behind.
  3. Transfer the clear soy sauce to a large heavy pot, cover, and heat over medium-high heat until it begins to boil, 20 -30 minutes.boil soy sauce
  4. Turn the heat down to medium and boil for 15 to 20 minutes to sterilize the sauce without boiling too much of it away. This step will create a very strong, persistent smell. Be careful carrying it out in closed areas, or around people who are sensitive to strong aromas.boiling soy sauce
  5. Remove the lid and cool the sauce down soy sauce
  6. Transfer the sauce to the sterilized glass jars. The soup soy sauce will keep indefinitely at room temperature.
  7. transfer ganjang


Leave your rating:

So far this is rated 5/5 from 274 votes

Be the first to rate this.


  1. maidafuentes Chile joined 9/22 & has 1 comment

    Hi Maangchi!! Hoping you are very well… I’m about to start making my first batch of soy sauce and i’m wondering if I can replace the jujubes with some regular dates or maybe just skip them , because we dont have them here in Chile.

    Thanks in advance!

  2. Pidgeonfood Massachusetts joined 10/19 & has 5 comments

    Mangchi! Lots of White dots and white mold on my Guk-ganjang! Is this okay if I just filter them out? I filtered after Doenjang, boiled, and then fermented again in my Onggi and lots more appeared. Is this okay?

  3. jayanth1255 India joined 12/18 & has 4 comments

    Can i keep sauce in glass bottle under direct sun till it turn very dark…??

  4. jayanth1255 India joined 12/18 & has 4 comments

    Thank you today I too made soy sauce, Sauce came out so dark and it has lot of foam, i just heated and filtered into a glass bottle….

  5. Kiss_the_cook Germany joined 7/17 & has 18 comments

    yesterday I started to soak my 2 mejus (only used 1kg of soybeans for this test run) in brine. I was lucky to buy a 2 gallon Hangari here in Germany.
    My question is about the Guk-ganjang. You store them in glas containers, but I would be able to get more and smaller Hangaris.
    I have a cellar, which is relatively cool even in summer (20° C max.). Do you think I would be able to store the Guk-ganjang in Hangaris instead of glass containers under these conditions?
    Also could you please say if one should mix some older Guk-ganjang with the next year’s batch like someone suggested here?
    Love your book, your recipes and you. ;)

    See full size image

    • Maangchi New York City joined 8/08 & has 12,045 comments

      Yes, you can keep the soy sauce in your earthenware jar (hangari) but it will still need sunlight to ferment. As time passes, the soy sauce will get more flavorful.

      Put the hangari in the sunny spot in your house and once in a while open the lid and expose it to sunlight.
      Good luck!

  6. Ardenda Minneapolis, MN joined 1/17 & has 4 comments

    Maangchi – I separated out my doenjang and guk ganjang. Tonight I boiled my guk ganjang (I actually really like the smell) and as my guk ganjang was cooling, it developed a layer of white crystals on the top. Is that ok? I skimmed them off and put them in glass jars anyway but I wasn’t sure what that was.

  7. nmai joined 5/15 & has 2 comments

    Maangchi!! Please make a video of this pretty please <3 <3 <3 <3 <3

  8. heri0n Canada joined 2/16 & has 1 comment

    Hi Maangchi, how does the ganjang last for hundreds of years – quantity wise? My best guess would be they make more ganjang and combine it, so the new ganjang takes on the flavour/bacteria/fungus of the old one, accelerating the process of aging? Or do they just use it sparingly?

    • Ibmollieeeeee Banning, CA joined 5/16 & has 1 comment

      I’d imagine it works like sourdough starter, kombucha, kefir, and other fermented foods. When you make a new batch, you have to take a little bit of your already fermented batch and add it into the new one. It gives the fermentation process a kick start.

      But maangchi I do have a question about this. Aren’t you basically pasteurizing the soy sauce by boiling it? Probiotic bacteria don’t live thru the heating process.. therefore any nutritious benefits of the soy sauce are then destroyed.

      • Chef Jim Corona California joined 2/18 & has 7 comments

        lbmollieeeeeee from Banning: Did you ever get an answer on your boiling question? I NEVER boil any ferment as that does kill all the probiotic bacteria. If you don’t boil the Doenjang, will it spoil?
        Thanks if you have a moment – Jim in Corona CA.

Leave a Reply

You must create a profile and be logged in to post a comment.