Soaking oak chips in bourbon

Thanks Mothergoose - that's what I expected, but I wonder if the same could be accomplished with more water and longer boiling time?

 

I have bottle of Makers Mark that's had oak cubes soaking in it for 5 years.

I should probably brew another batch of bourbon breakfast stout soon...

 

I prefer my oak tanins unadulterated...taste often and remove promptly when desired level of adjunctification is achieved.

 

I would probably add the oak directly, if I wasn't also looking for a bourbon taste (making an Innis & Gunn clone). I know you can pre-soak with bourbon, but that seems like a waste when you have to toss the pre-soaked bourbon out. So, I'm exploring the concept of pre-soaking with boiled water to remove the initial tannins, followed by soaking in bourbon for a week or so, then tossing both in the secondary for a couple of weeks. However, boiling it three separate times seems like unnecessary extra work, when it can possibly be accomplished by a single, longer boil with more water.

 

I've used 0.3oz of oak cubes in one gallon of RIS and got a fair amount of vanilla character from the oak. I let the wort sit on the cubes for 28 days.

 

Alhtough I've never oaked any beer to date (planning to in the next week), I've now done a significant amount of research on wood aging beer. In terms of sterilization, soaking oak chips/cubes in spirits like Bourbon seems to do little to kill all the microbes. You would optimally need a spirit in the 70% alcohol range (140 proof), and there's no guarantee that it would penetrate all through the cubes (chips would likely be OK). Jamil Zainasheff agrees and sees little purpose in soaking your chips/cubes in spirits. If you want, say, Bourbon flavour in your beer, he says to just add it separately to the beer, and adjust the amount by taste. Only afterwards do you add the chips/cubes and age while regularly tasting the beer.

Jamil says that sterilizing oak in strong beers is likely not necessary because the alcohol content will likely prevent any living organisms from becoming active. However, he suggests that sterilizing oak in lighter beers is probably a good idea. So the question really comes down to: how should the chips/cubes be sterilized, since normal strength spirits are not effective? Jamil pressure cooks his chips/cubes in a small Mason jar with a dash of water to generate steam. He also says that you can boil a half cup or full cup of water, pour it over the oak in a heat-proof container, and let it steep for 15-20 minutes. Once cool, it's ready to go. I question whether either of these two methods actually penetrates to the core of the oak cubes.

I have seen other methods which suggest sterilizing the chips/cubes by placing them in an oven for a period of time. This seems to be a much more effective method, in my opinion. You spread the chips/cubes on a cookie sheet and leave them in the oven at about 200 F for about 15 minutes or so. This pasteurizes them because the temperature is in excess of 138 F (the minimum temperature for Pasteurization). The heat would also be able to penetrate through the entire oak cubes during that time. Any temperature higher than about 200 F seems to be unnecessary, and would only begin to approach the temperatures used to roast the oak chips/cubes in the first place, to bring them to medium roast (for medium toast, they are usually roasted at about 350-375 F).

The remaining question is, what about the excess tannins? Jamil says that tannins are actually good for the beer taste, as long as they are not excessive. Boiling oak seems to bring out the tannins rapidly, but while they are in the beer, the flavours and tannins come out slowly, and can be monitored by frequent sampling.

So what I will likely do is:

1. Wait until my beer has completely fermented and is in the keg;
2. Add enough bourbon to flavour the beer to taste (I'll start with about 4-6 ounces);
3. Pasteurize the chips/cubes in the oven at 200 F for about 15-20 minutes;
4. Add the Pasteurized chips/cubes to a hop bag or stainless steel hop filter and hang it from the inside lid of my keg;
5. Place the keg in my keezer and bring the temperature down to serving temperature;
6. Pressurize the keg;
7. Taste a sample of the beer every week or so;
8. Remove the oak when the beer tastes a little more oaked than I would like; and
9. Continue to age the beer as the oak becomes more mellow and continues to contribute more vanilla and caramel flavours.

I look forward to any further suggestions, improvements or corrections to this approach.

 

Stavin oak cubes are steam sterilized before packaging.

I boil them for 10 minutes to reduce the tannins. There are plenty of tannins left after the boil.

 

Unfortunately, the brewing supply stores in this area buy the oak in bulk and repackage them - thus they are no longer sterilized.