Sake kasu (sake lees) substitutes

The workhorse approximation. White miso gives the thick spreadable body and the fermented savoury depth, the sake brings back the rice-wine aroma and a hint of alcohol, and the sugar covers the mild sweetness kasu has naturally. Mash it smooth and use it exactly as you would a kasu bed.

Best for

kasuzuke black cod or salmon, marinated chicken, pickled cucumber and daikon, glazed vegetables

Two real differences to plan for. It is saltier, so cut any other salt in the recipe and shorten the marinating time by about a third. And it has far more sugar and protein than kasu, so it browns and burns much faster: move the fish further from the broiler and wipe the excess paste off before cooking. The flavour reads distinctly of miso rather than of yeast and rice.

Shio koji is salted rice koji, so it shares the actual koji mould that kasu was built on. That means it is the closest match on the thing kasu quietly does best, which is enzymatic tenderising: the proteases break down the surface of fish and meat and make it silky and deeply seasoned.

Best for

marinating fish, chicken and pork, quick vegetable pickles

It is thin and pourable where kasu is a thick paste, so it will not sit on a fillet as a bed, and it will not form a glaze. Add miso if you need it to cling. The flavour is cleaner, sweeter and less yeasty, so a kasuzuke made this way tastes elegant and delicate but misses the rustic bready funk. Do not marinate longer than about a day; shio koji works fast and can turn fish mushy.

This sounds odd and works better than almost anything else, because discard is the only common ingredient with the same combination of thick pale paste, live yeast smell and mild sourness. It is the closest match on aroma of any option here.

Best for

kasuzuke-style fish, marinating pork, pickling root vegetables

The sourness is more pronounced than kasu's, which is faintly tart rather than genuinely sour, so use a young discard rather than a jar that has been in the fridge for two weeks. It also contains gluten, and it browns quickly. Wipe the paste off before grilling. Treat this as a refrigerated marinade only, not a preservation method.

Rather than trying to imitate kasu, this leans into being a different classic Japanese marinade. Miso, mirin and sake with a little sugar is the saikyo miso or misoyaki marinade, which is what most Western restaurants serving so-called kasu cod actually use.

Best for

black cod, salmon, sea bass, chicken thighs, aubergine

Sweeter, glossier and darker than kasuzuke, with a lacquered caramelised surface rather than kasu's pale one. Nobody will think it is kasuzuke, and nobody will complain. Marinate fish 24 to 48 hours in the fridge, then wipe most of it off, because the sugar burns.

A dairy route that covers the tang and the thick clinging texture at once, and the lactic acid does a modest amount of the tenderising that kasu's enzymes would have done. Useful when you have no sake, no mirin and no koji.

Best for

marinating chicken, marinating firm fish, pork chops

Tastes closer to a yogurt marinade than to anything Japanese, with a clear dairy note, and it will scorch and speckle on a hot grill. Good on chicken, less convincing on delicate white fish. Not a route for a recipe that needs to taste authentically of kasu.

In kasujiru, the winter soup built on sake lees, the kasu is the entire flavour of the dish. The nearest thing is a milky soup made with white miso plus a splash of sake plus a few tablespoons of unsweetened soy milk or blended cooked rice for the cloudy body, and it is genuinely a different soup.

Best for

understanding when to change plans

Kasu keeps for months tightly wrapped in the fridge and for a year or more in the freezer, and Japanese grocers sell it cheaply in flat plastic-wrapped sheets or tubs, often only in the colder months since it is a by-product of the winter brewing season. If you cook this style of food regularly, buying a block and freezing it in portions is a better long-term answer than any substitute.