The writer is learning continuously with more people using it, and we correcting the imperfections as we spot them. There is no end to the ways in which people may enter ingredients. Our bet is, once the user get to see how it is presented on the final output, the second time they will start visualising the way it needs to be entered. A bit of mutual learning. Meanwhile, we keep looking for patterns and keep correcting these rough edges.
Also there are tons of use cases that we try to solve here. For instance, people who have recipes stored on their personal Onenote/Evernotes accounts or blogs can simply copy/paste the ingredients and steps to the free form editor.This would not have been possible in a structured form.
http://raymondsfood.cucumbertown.com/ recreated around 100 recipes from his blog over a weekend using the editor! Sure, it could still render buggy, but it is possible to iron out the bugs with more data coming in and patterns detected.
* '2 oz of butter' becomes 'butter 2 oz of'.
* '2 rashers of bacon' becomes 'rashers of bacon 2'.
it's wrong for some things, with apparently no workaround:
* 'five-spice powder' becomes 'spice powder five-'
* 'three cheese coleslaw' becomes 'cheese coleslaw three'
Apart from the last two - can't you just highlight the numbers without moving them?
Edited to add: looking at the way the recipes are presented on the site - with the quantities in a different column, rather than tagged on the end - makes me think that it would be clearer if it looked that way in the editor too, so you don't think of it as a sentence.