No,
Unfortunately the brewsheet is not something you can edit within the program at the moment.
However, if you are ambitious, you can try the following:
1. Go to the main recipe view (i.e. don't open the recipe), and put the preview window in brewsheet mode by clicking the "Preview as brewsheet" button. You should see the brewsheet for the currently selected recipe in the preview pane.
2. Right click on the preview pane and pick the "Select All" command.
3. Right click on it again and select "Copy".
4. Open up a word processor such as Microsoft Word and then paste the text into it.
If everything went well you now have the brewsheet imported into Microsoft word where you can now edit it.
Cheers!
Brad