1. Making toasted oak chips

Important: Make sure you use oak or non-resinous wood - using a soft resinous pine will only give you a retsina. Be ingenious when looking for old oak – be very careful to use bits of old furniture etc (after shaving off the varnishes etc).

How to toast oak:

Method 1: Use a tin with a push on lid of 1-2L. Split your timber into thin enough strips to fit your bottles. Light the pieces, and when well charred, place in the tin. Place the lid on lightly to snuff out the flames. Add more wood as it becomes ready, replacing the lid each time. When cooled, push the lid on tightly to retain the Smokey aroma until ready to use.

Method 2: Another way is to wrap the oak chips/shavings in aluminum foil, and bake them in your oven for a while.

Method 3:  using fresh wood: Split the wood into finger- width sticks about 4 to 6 inches long, then pack them into an old coffee can that has no more of that coffee smell or any rust. Pack them in standing upright so there isn't much space between them. Once the can has a solid layer of these sticks crammed in together like sardines standing upright, cover the top of the can with a layer of heavy tinfoil that has a pencil sized hole in the middle of it. Place this arrangement on a propane burner, and set the heat on high. After a bit of heating up, some steam, then other various flammable organic gases will evolve off (if the foil swells up, make the hole a bit larger- try not to burn yourself). Once there is no more gas/steam coming out, turn off the heat and let the can sit outside to cool on it's own with a cover to exclude any air from getting in. Once cool, rinse any ash off in some cold water and use however you wish. Do not poke any holes in the coffee can - that will allow air into the mix and turn all of the wood into ashes, instead of turning it into charcoal.

Wood-essence: Can be made by soaking the shavings or toasted wood in 70% alcohol for a couple of weeks, then strain them off.  

Quercus Alba (American White Oak) take equal proportions (by volume) of chips and neutral spirit at about 70% and soak for approximately one month, agitating as often as possible or percolate using a pump, then separate the two and apply solution (tincture) at a rate of about 10/15 ml per liter, or to taste of spirit at 40%. Or if you want to be really up market, take the tincture and simmer it very slowly until the volume is 75% less than original and you should have a fairly concentrated essence.

 

2. Buying oak chips

Several types commercial packaged oak chips can be bought in Brewshops and through the internet. I recommend to check out your favorite brewshop for the various types. 

 

3. Finally - the maturing process with oak chips

Oaking - Several different flavors can come from a single type of oak if alcohol strength is adjusted during maturation.

•  55%-53% will give vanillin’s
• 40%-50% will give a mix of vanillin’s and sugars
• 40%-49% will give sugars.

General approach: 

Start by using one teaspoon of oak per liter of alcohol, and let it soak for a week. Taste test frequently to find the level of flavor intensity that suits you - e.g. maybe a little more oak, or longer, or different % alcohol, or different levels of oak toasting.

 

My way of working:

I add about 70 square cm of oak per liter of 55% spirit. Keep in mind that one "strip" of oak has two surfaces that interact with the spirit. I age spirits in 4 liter glass bottles and add thin strips (<1mm) of oak that I had wrapped in aluminum foil and lightly charred on the stovetop. So if my oak strips are 2 cm wide I cut a total length of 70 cm, but I usually break such a strip into a few pieces before charring and adding them to the jug.

What I like to do is start at 55%-53% for first phase (1 to 2 months) then dilute to 40% (3- 12 months). In this manner I am adding sugar from the cells of the wood while I marry the dilution water to the whiskey. This results in rich vanilla oak character with silky legs that cling to the side of the glass.

 

Another way to apply toasted oak to age bourbon/whisky (for one bottle)

1. Line up bottles to be used, add your undiluted spirit, and put in appropriate amount of flavoring. Personally, if it says 10ml per liter, I add 15ml.
2. In a stainless steel saucepan, put in amount of water needed to top up one bottle only. Add one tablespoon of toasted oak chips.
3. Bring to boil, then immediately turn heat down and simmer. We don't want to boil off all the aromatics of the oak. At this stage add a large teaspoon of glucose and stir in well.
4. Simmer for about 5 minutes, bring to boil again, then take off heat and let cool. The mixture should be a lovely brown color.
5. Strain and add cooled mixture to your bottle of spirit and it is ready to drink. Or don't strain, and keep the flavor coming for an even smoother, flavorful drop in the future.