I made an AG bourbon porter. I boiled the oak chips for a few minutes then soaked then in bourbon for 2 weeks (while the wort was in the primary). I then added them into wort in secondary for 2 weeks. I was told that you could leave them in longer, but that would give a stronger bourbon flavor. I bottled a couple months ago and let it age for 4 weeks before I started tasting. Now, 3 months later, the bourbon taste is really smoothing out and blending well with the beer. I used French oak chips. Hope this helps.