Sansho pepper is essential for a traditional Japanese take on fatty dishes like grilled eel and duck. Its heat and citrus notes are great complements for both of those proteins, but the spice may not be the easiest to find in an emergency. If you need a fast sansho pepper substitute, choose one from the list below.
Your best bet: Szechuan pepper
Szechuan pepper is a relative of sansho pepper. Both come from similar members of the prickly ash family, which are relatives of citrus plants. The two spices are similar enough that many believe them to be the same spice. While they are not the same, they are close enough that you can use them interchangeably. The citrus connection is what explains the lemony tang that you get from both varieties. Sansho pepper actually has a stronger citrus note than Szechuan pepper.
Neither spice is related to Piper nigrum but the heat in both is the result of sanshools, compounds belonging to the same family as the piperine in black pepper. Szechuan pepper provides a similar level of heat as well as the same numbing effect that sansho pepper would provide. Both Szechuan and sansho peppers consist of the husks of the berry with the seeds discarded.
Use Szechuan pepper as a 1:1 substitute for sansho pepper.
A decent second choice: Lemon pepper
If you want the lemon notes along with a little peppery heat, the lemon pepper spice blend provides exactly that. It is also important to consider availability when determining whether an ingredient makes a good substitute. Lemon pepper is easy to find in most grocery stores; it is not limited to Asian markets the way Szechuan and sansho peppers are.
In addition to being easier to find, lemon pepper is also much less expensive than the other substitutes on this list. Another big benefit is the fact that you can make it yourself. All you need is some black pepper and a little lemon zest. Mix them in equal amounts and use the blend exactly as you would use sansho pepper.
Use lemon pepper as a 1:1 substitute for sansho pepper.
A decent second choice: Nanami togarashi
Nanami togarashi makes a great sansho pepper substitute for a number of reasons beginning with the fact that it is Japanese, which means that it is formulated for the same flavor aesthetic that prizes sansho pepper. Another important reason is that it actually contains sansho pepper. The sansho pepper in nanami togarashi is a part of a blend, which means that there will be less of it in your dish; however, other components in the blend include citrus zest (orange or yuzu) and chile peppers. Both of those spices provide exactly the flavor profile that you want from sansho pepper; namely, heat and citrus flavor.
Use nanami togarashi as a 1:1 substitute for sansho pepper.
Shichimi togarashi is very similar to nanami togarashi but with a lower proportion of citrus zest. Even so, the citrus flavor is still there as is the heat from the sansho pepper. While it is not quite as a good a substitute as nanami togarashi, it is an effective one and should work well in most applications.