This method uses only soybean koji and sea salt, with the proportions varying depending on how long the koji is washed for. In general, the ratio by volume is approximately 1 part koji to 0.2 parts salt (though a practical working ratio of 5:1 is easier to understand). The longer the koji is washed for, the more water it absorbs, and the higher the required salt content will be.

This is Taiwan’s most traditional brewing method, producing a rich aroma known to the older generation as the 'flavor of the sauce jar.' More precisely, the aroma profile of dry-brewed soy sauce resembles that of preserved mustard greens. Purely dry-brewed soy sauce is also excellent for adding color to dishes.

The aroma profile of wet-brewed sauce is reminiscent of seaweed paste or fresh kelp. By volume, the brewing ratio is about 1 part soybean koji to 0.3–0.6 parts brine. Because of the high koji concentration, the mixture cannot be stirred during fermentation.

Compared to dry-brewed sauces, wet-brewed yimyu is less salty and smoother in taste. It also posesses a richer aroma and a more pronounced soy fragrance than water-brewed yimyu.

Here, the ratio by volume is about 1 part koji to 1–1.5 parts brine. Depending on the temperature and humidity of the brewing environment and the saline level of the brine, the koji may need to be rinsed and the mixture may need to be stirred during fermentation.

The aroma of water-brewed yimyu resembles that of chicken bouillon.

This method descends from the Japanese saishikomi shōyu (double-brewed soy sauce) technique and resembles the water-brewing method, with one key difference: instead of brine, matured soy sauce is used together with fresh soybean koji for a second fermentation. As a result, this process requires twice the ingredients and twice the fermentation time.

In Taiwan, ratios and procedures vary from maker to maker, and there is no fixed standard. However, the different kinds of double-brewed yimyu all share a rich umami flavor and an enhanced aroma. The top notes often carry a floral fragrance, and the overall aroma profile is reminiscent of hops in beer.

This method is mainly used in Keelung, New Taipei, Taipei, and Yilan – all areas with frequent rainfall. Because these regions have a shorter period of suitable weather for solar fermentation – lasting roughly from the Dragon Boat Festival to the Mid-Autumn Festival – the fermentation cycle is shortened to 21–30 days. Around the 14th day, glutinous rice is added, becoming part of the fermentation process. The sauce’s flavor is developed primarily through extended heating after fermentation, giving it an aroma akin to caramel or malt extract.