I can't seem to find the last ingredient. I am missing the "Key to friendship" ingredient, got all the other parts.
If you just keep brewing, an old friend will come along and ask you for a favor. He'll hand over the key as thanks.
Specifically, Eddy will ask you to brew a high quality batch of beer from his awful recipe (Quality Cap 0!) to help him get his own brewery dreams off the ground. In thanks, he'll give you the keys to the Bodega.