Age your steaks with fish sauce and koji
Some things, like love or a delicious shrimp basecan’t be rushed, but a lot of things can be approximated. While there’s no substitute for a real dry-aged steak, there are two ingredients that food geeks swear will help bring you closer: koji and fish sauce.
The principle behind each is the same: the enzymes in the ingredients break down the meat, improving both flavor and texture, rather than letting the meat’s natural enzymes do it slowly over time. The expected result is a denser, nuttier steak with lots of umami. Instead of dry aging, it’s lie aging. Both shortcuts make a lot of sense, but I wanted to see if one ingredient was a better liar than the other, so I bought a few cheap steaks and ran a (tasty) experiment.
Just Koji Rice
Koji, aka “Aspergillus oryzae”, is a fungus that is most often used to ferment soy sauce, miso, and sake. You can buy it on fuzzy, inoculated rice either in line or at your local Asian grocery store. When coated on meat, koji breaks down protein and carbohydrates into sugars and amino acids, while removing moisture, resulting in a more tender and flavorful steak.
To exploit koji’s tasty lies, enjoy your food recommended break up the rice in a blender (I used a food processor), rub it all over the meat and let it hang out in the fridge for a few days, so I did just that. As the steak cooled, all coated in fuzz, a savory, meaty, slightly nutty, tangy aroma permeated the fridge. It was actually quite enjoyable. After three days, I rinsed all the koji off the meat and wiped it off.
The meat was a little firmer, was noticeably darker, and still had that nutty, meaty aroma. I seasoned it generously with salt, then seared it in butter for a few minutes on each side.
It developed a nice crust quite easily and when I took a bite it was unmistakable that it was flavorful and tender.
However, unlike using a marinade—like these, which are excellent-the meat didn’t taste like any other ingredient. It was just a meatier, slightly sweeter, more concentrated version of itself. Although I wouldn’t say it tasted like a 50 day old rib eye, but it tasted better than any other top sirloin I had eaten before. In short: koji is a very good liar.
Just fish sauce
The fish sauce method—from modernist kitchen at home by Nathan Myhrvold— takes a bit longer than making koji, but is based on the same principles. Instead of letting the enzymes naturally present in the steak break down on their own, the enzymes in the pungent elixir help it. The recipe is simple: just coat your steak in fish sauce, seal it as tightly as possible in a plastic bag (I used my vacuum sealer) and wait three days. Once this time has elapsed, remove the steak from the bag, wrap it well in cheesecloth and return it to the refrigerator for another three days.
After performing these steps, I removed the steak from the bag. There was nothing to wipe or rinse, and the meat was about the same color as koji’s steak, but the smell was a little more pungent and less nutty.
The steak also formed a nice crust quite easily, but this one was much more brown in color.
The meat was tender and the flavor was strong and meaty, and there was an underlying taste that I can only describe as “excellent”. It was quite intense, almost to the point of being entertaining, and I love this. It lacked the nutty sweetness I enjoyed when eating the koji aged steak though. This made me want to combine the two methods.
Koji + Fish Sauce
As you might expect, combining the two methods involved coating it in koji, letting it hang for three days, then rinsing the koji and coating it in fish sauce and letting it hang for three days. more, before wrapping it in cheesecloth. last three days in the refrigerator. As you can see in the photo above – which is of a sirloin tip this time, as that’s what they had when I went back for another steak – the meat has blackened a bit more.
And as you can see on this picture, he also formed a nice crust when seared.
The flavor was fantastic. It had the intense, almost aggressive meaty quality imparted by the fish sauce, with a nutty sweetness imparted by the koji. It’s a bit what I expected, but experiences don’t always go as I expected, and I was very pleasantly surprised. It was by far my favorite, but it took nine days, or over a week, which seems a bit long. If you need an elongated steak in a shorter order and can only use one enzyme aid, you should get koji. Not only does it only take three days to do its job, but it results in a more balanced and nuttier steak. (And it looks cool.)