You could be inspired by the link reference syntax from markdown, and use the following where subs are possible:

add @acid{1%tsp} to @milk{1%cup} to create acidulated milk

[acid]{lemon juice|apple cider vinegar}

Anyway great spec and language!

I'd suggest to open an issue for tracking in spec repo https://github.com/cooklang/spec, so people can discuss different options.

Lots missing really, you can add nutrition and scaling things to that list.

Good point, any idea how it could look like?

How about

  [@raw organic cane sugar, @honey]{3%tbsp}

Here square brackets indicate that the ingredient will have variations separated by commas.

Interesting idea, how about the case when quantity varies for different ingredient? For example 2 tbsp of raw organic cane sugar or 3 honey.

Good idea. I'd prefer the at sign in front of the brackets, though.

  @[sugar, honey]{3%tbsp}

It should be easier to parse and allows for brackets to be used elsewhere without escapes.