Japanese Curry Roux, From Scratch

A homemade replacement for the boxed roux blocks — make it, chill it, cut it into cubes, and use it exactly as you would use S&B Golden Curry or House Vermont.

The blocks exist for a good reason. S&B made Japan’s first domestic curry powder in 1923, but powder degraded badly in a hot, humid climate, so the industry moved to selling the spice already cooked into fat and flour, moulded into a bar that breaks into cubes. It is shelf-stable, pre-portioned, and thickens the sauce for you — the British curry-powder tin’s logic taken one step further.

And note what the technique actually is: a FRENCH roux, doing the job an Indian cook does with ghee. Japanese curry came to Japan through the British Royal Navy, so it arrived carrying European kitchen technique. Same chemistry as blooming spices in ghee, completely different genealogy.

Ingredients

The roux

• 6 Tbsp / 85 g unsalted butter
• 1/2 cup / 65 g all-purpose flour

The spice

• 3 Tbsp curry powder
• 1 Tbsp garam masala
• 1 tsp ground cumin
• 1 tsp ground coriander
• 1/2 tsp ground turmeric
• 1/2 tsp cayenne, or to taste
• 1/4 tsp ground cinnamon
• 1/4 tsp ground cloves

The Japanese half — what makes it taste Japanese rather than Indian

• 1 Tbsp tomato paste
• 1 Tbsp Worcestershire sauce
• 1 Tbsp soy sauce
• 1 Tbsp honey
• 1 tsp instant coffee granules or 1/2 oz dark chocolate (optional but good)
• 1 tsp salt

Directions

Key ingredients

Soy Sauce · Worcestershire Sauce · Garam Masala · Curry Powder, Madras · Cinnamon · Honey

1. Melt the butter in a heavy saucepan over medium-low heat.
2. Whisk in the flour and cook it, stirring more or less continuously, for 15-20 minutes. You are making a blond-to-light-brown roux — it should go from pale and pasty to loose, nutty-smelling and the colour of peanut butter. This is the longest step and it is not one to rush; under-cooked flour tastes like paste and will make the finished curry gluey.
3. Take the pan OFF the heat before the spices go in. Ground spice scorches instantly in a hot roux and burnt curry powder is bitter all the way through.
4. Stir in all the ground spices and let the residual heat bloom them for about a minute. They should smell cooked rather than dusty. Back on very low heat for 30 seconds if it needs it.
5. Beat in the tomato paste, Worcestershire, soy, honey, coffee or chocolate, and salt until you have a thick, smooth, dark paste that pulls away from the pan.
6. Spread it into a small parchment-lined dish or an ice-cube tray, cool, then refrigerate until firm — a couple of hours.
7. Cut it into cubes. You now have exactly what is in the box. Keeps a month in the fridge, six months frozen.
8. To make curry with it: brown your meat, cook onion down properly (fifteen minutes, until it is genuinely browned), add carrot and potato, cover with water or stock and simmer until the vegetables are tender.
9. Then take the pot OFF the boil and dissolve the cubes in. This is the one rule that matters: adding roux to a hard boil gives you lumps. Ladle a little hot broth into a bowl, melt the cubes in that, stir the smooth mixture back into the pot, and simmer gently 5-10 minutes to thicken.

Notes

The apple is not a secret ingredient My other Japanese curry recipe calls grated apple “the secret ingredient,” which is a good instinct and slightly overstated. It has been printed on the front of the best-selling curry box in Japan since 1963: House Vermont Curry is sold as “curry with a touch of apple and honey.” Apple and honey are the stated formula, not a trick. Grate half an apple into the pot if you want that profile; there is honey in the roux above already.

And why it is called Vermont This is my favourite fact in the whole subject. In 1958 a Vermont doctor named D. C. Jarvis published Folk Medicine: A Vermont Doctor’s Guide to Good Health, promoting “honegar” — apple cider vinegar and honey — as a cure for more or less everything. It was a runaway bestseller, it was translated, and “Vermont therapy” became a health fad in Japan. House Foods happened to be developing a mild, sweet curry aimed at CHILDREN, sweetened with apple and honey — the same two things the fad was about. So they put Vermont on the box.

A Japanese curry, descended from a British naval ration, named after an American folk-medicine craze. Four countries and a fad, in one box on a supermarket shelf.

Why Japan has curry at all The Imperial Japanese Navy adopted it from the British in the 1870s-80s. The navy had a beriberi catastrophe — thiamine deficiency caused by a diet of polished white rice — and Takaki Kanehiro, a naval physician trained in Britain, ran the comparison: a nine-month 1883 voyage produced 169 cases in 376 men and 25 deaths; the 1884 repeat, on a diet with more barley, meat, milk, bread and vegetables, produced 16 cases in 333 and no deaths. Curry delivered that diet to a lot of sailors from one pot, so it went into the ration and stayed. The Japan Maritime Self-Defense Force still serves curry on Fridays.

Worth adding that Takaki’s own explanation was WRONG — he reasoned about a nitrogen-to-carbon ratio, because vitamins had not been discovered yet. He got the intervention right and the mechanism wrong.

Serving Over rice (karē raisu); with a breaded cutlet on top (katsu karē); thinned with dashi over thick noodles (karē udon); or sealed in bread dough, crumbed and fried (karē pan). And serve it with fukujinzuke, the red-brown pickled relish, or rakkyo, pickled Chinese scallions. Not optional in my view — the sauce is rich and flat without something sharp beside it.

Mixing brands If you are using boxes rather than this, a very common Japanese home-cook move is to use two different brands together — a box of S&B Golden Curry for spice plus a box of House Vermont for sweetness. Worth knowing that it is normal rather than a compromise.