Step 1 / 5

vegetable peeler, wide strips, no white pith — substitute-citrus branch only

lemon, peeled in wide strips before it is juiced, taking only the coloured layer. This step belongs to the substitution and not to the tradition: yuzu carries a floral, resinous perfume that no lemon has, and since most of any citrus's aroma sits in oil glands in the peel rather than in the juice, steeping the peel is the documented way to recover some of the difference. Skip it entirely if you have real yuzu, sudachi or kabosu — the traditional formulations use juice alone and the added peel would muddy them. Take no pith: pith carries no aroma oil and contributes only bitterness, which a sauce steeping overnight has plenty of time to extract