My journey to dry aging fish for sushi
Updated: Oct 13, 2022
I had just finished my shift and plopped down in front of my 30 inch tv set a top cinderblocks and cracked open a miller lite and chewed on a microwaved pizza. I hit play on my VHS player and adjusted the tracking. One of my chef friends has let a dubbed copy of Iron Chef. This isn't the Iron Chef America with Alton Brown, Cat Cora, Bobby Flay, and Jose Garces. No, no... this is the OG Iron Chef with the voiceovers and Chairman Kaga taking a bite out of a yellow bell pepper.
Today's secret ingredient is snapper and after an hour the show competition is complete and Chef Sakai is victorious again. The screen goes fuzzy and the tracking needs to be adjusted again. The tape cuts to a Japanese show with a old sushi chef talking about tuna. Unfortunately, it's in Japanese with no English translation so I really don't know what he's say but it's obvious he is excited to be talking about tuna.
He has just received a super fresh block of bluefin tuna straight from the fisherman. But instead of serving it to his guests, he has wrapped it tightly with tuna paper and then with plastic wrap and plunged it into a vat of ice. He demonstrates how he will repeat this process every other day over the next 14 days. B-roll dramatically shows the process repeated in slow mo.
On the 14th day, he removes the plastic, then the tuna paper. The tuna is greyish black and unappetizing. The chef then slowly draws his longest yanagi from its sheath and cuts a cross section of the loin to reveal the ruby red core. He enthusiastically points at the core and states,"Oshii!". He then proceeds to trim off all areas of the fish that are not red, which winds up being about 2/3rds of this tuna loin. He finally presents the saku block to the camera. We quickly cut to him behind the sushi bar slicing up the tuna for nigiri. The tuna is simply served with a glossy swipe of nikiri and a dollop of fresh wasabi.
I would not try this technique for another 10 years when I finally had my owned restaurant. The first time i tried it was with kanpachi. We performed all the same steps: skinned the fish, wrapped with tuna paper, wrapped with plastic, put into ice, and repeated for 14 days. The result: the outside was brown and slightly smelly but after trimming all that away, what was revealed was the creamiest, most decadent kanpachi I had ever tasted. It was so soft we could almost spread it on toast! We tried this same process again with tuna. Just like the Japanese chef, we lost 2/3rds of the tuna but were left with the most delicious and tender tuna I had ever had.
What I learned about "wet" aging was:
Wet aged fish becomes incredibly tender and depth of flavor.
Flavor is pleasantly funky.
It is a very wasteful process. Typical yield is about 33%. Not to mention, all the paper and plastic wrap used.
It requires a lot of time and attention. The paper and plastic changes every other day and ice management daily, sometimes twice.
It is NOT scalable. With all these steps, it would be impossible to replicate in a busy restaurant.
Aging had such great benefits, we wanted to figure out how we could make it feasible in a high volume restaurant environment. After some intense research about fish storage and aging, I found out about a couple of guys dry aging fish: Liwei Liao (@dry_aged_fish_guy) and Josh Niland (@mrniland). These guys were scaling, gutting, and gilling their fish WHOLE and then hanging them up by their tails in their walk-in coolers and reach-in refrigerators.
We decided to give this a try! With our limited space, we decided to try it with whole kanpachi and suzuki. We scaled the fish using the japanese scaling technique, sukibiki, and then roped the fish to our speed rack and let them hang out. 7 days later we came back to taste. The results surprised us and were completely DIFFERENT than wet aging.
What we learned was:
As expected, the skin and first millimeter of the fish was tough and unusable but the yield was only 5-10% less than normal yield.
The fish texture was firm but tender, not soft like wet aging.
Subtle flavor nuances were expressed through this process. For the suzuki, hints of chlorophyll and minerality. For the kanpachi, rich mouthfeel with a nutty finish.
No funky flavor.
This process required mastery of fish fabrication technique but is otherwise hands off.
It is a scalable process.
Excited about this new process, we went all in. In December 2020, we purchased a unit from DryAger and then a second unit 6 months later. The Dry ager refridgerator allowed us control temperature to a tenth of a degree and humidity to a tenth of a percent. We started dry aging all our fish from tuna to scallops! We wound up setting our dry agers to different humidities. One exclusively for tuna and the other for sukibikied fish.
This is where our dry aging journey began. Our next task was to test the limits of dry aging. We decided to dry age 5 pieces of Big Glory Bay King Salmon at different intervals to compare flavor, texture, and yield. This is what we found.