2 ingredients to grind to make item won't work

[snick]

I'm trying to add this to the grinding cfg:

//pitcher of milk + cloth -> cheese
item 4
{
mill_item 4
product_objtype 0x097E
product_amount 1
product_name wheel of cheese
ground_item 0x1765 1
ground_item 0x09ad 1
}

This does work but whichever ingredient you have listed first it's used to make cheese without the second item. Is there anyway I can change this to require both ingredients to make cheese?

[snick]

I found out I had to also change the grinding src to reflect the 2 ingredients and to use both up.