Using Wood Chips and Staves in Fermentation
Oak chips, cubes, spirals and staves give barrel character without a barrel. Here is how much to use, how long, which toast, and how to sanitize the wood.
In this post
The short answer: oak chips, cubes, spirals and staves give beer oak, vanilla and toast flavours without a barrel. Chips work in days but can taste harsh; cubes and spirals take weeks and taste smoother. A common starting point is about 1 to 2 oz (28 to 57 g) of cubes per 5 gal (19 L) for 2 to 8 weeks, tasting as you go. Steam or soak the wood first to sanitize it, in bourbon or wine if you want that character too.
| Form | Starting dose per 5 gal (19 L) | Speed | Character |
|---|---|---|---|
| Chips | 1–2 oz (28–57 g) | Days to a week | Fast, can be sharp or woody |
| Cubes | 1–2 oz (28–57 g) | 2–8 weeks | Rounder, more barrel-like |
| Spirals | Maker’s dose | 2–6 weeks | Like cubes; easy to remove |
| Staves | Maker’s dose | Weeks to months | Closest to a real barrel |
| Toast | Flavour |
|---|---|
| Light | Fresh wood, coconut |
| Medium | Vanilla, caramel, toast |
| Heavy | Smoke, coffee, dark chocolate |
How to oak a beer, step by step
- Pick the form, the oak and the toast from the tables. Medium-toast American oak cubes are the usual first try.
- Sanitize the wood. Steam it, or pour boiling water over it, let it sit a few minutes and drain. A long boil pulls out flavour and tannin, which is only useful if you want less oak. Soaking in spirit also sanitizes (below).
- Add it once primary fermentation is done, in the fermenter or a keg. That way you taste the finished beer and judge the oak on its own. A sanitized mesh bag, weighed down with something stainless, makes the wood easy to pull out.
- Taste often: every couple of days for chips, weekly for cubes, spirals and staves.
- Stop when it tastes right, or slightly before. Pull the bag, or move the beer off the wood.
In a Unitank, add chips or cubes the same way you dry hop, through the Oxygen-free HopDrop: load it, purge it with CO₂ and drop the wood in without opening the tank to air. When the flavour is right, transfer the beer off the wood into kegs.
Soaking oak in spirits or wine
This is how to fake a bourbon-barrel or wine-barrel beer.
- Put the cubes or spiral in a sanitized jar and just cover them with bourbon, rum, whisky or wine.
- Seal and leave them for a week or more. The spirit sanitizes the wood and the wood takes up the spirit.
- Add the wood to the beer. Keep the soaking liquid: it’s now oaky too.
- At packaging, add some of that liquid a little at a time, tasting after each addition, if you want more spirit.
American, French or Hungarian oak
| Oak | Character | Good for |
|---|---|---|
| American | Bold vanilla, coconut, sweet | Stouts, porters, barleywines, bourbon-style beers |
| French | Subtler, spicy, finer tannin | Belgian ales, sours, lighter beers |
| Hungarian | Between the two, often spicy | Either |
Oak is the standard because its vanilla and toast suit beer. If you experiment with other woods, such as cherry or maple, buy wood sold for brewing, winemaking or food use, never lumber, which may be treated.
Troubleshooting
| Problem | Cause | Fix |
|---|---|---|
| Harsh, tannic, like sawdust | Too much wood, too long, or chips | Pull the wood. Harsh oak often softens over a few weeks of conditioning; if not, blend with unoaked beer. |
| Raw, green wood | Untoasted or very light toast | Use medium toast next time |
| Hardly any oak | Too little time, reused wood, or wood boiled too long | Give cubes more weeks; add fresh wood |
| Sour or funky | Wood reused from a Brett or sour beer | Keep wood from wild beers for wild beers only |
Frequently asked questions
Can I reuse oak cubes?
Yes, but each use gives less flavour. Wood that has been in a Brett or sour beer holds those microbes deep in the grain, so it goes in the wild box, not back into a clean beer.
Is oak in a fermenter the same as a barrel?
Not quite. Oak alternatives give the flavour of the wood and whatever you soaked it in. A barrel also lets in a slow trickle of oxygen and may carry its own microbes. See what barrel aging does to flavour.
Can I add oak to a keg?
Yes, in a sanitized mesh bag. It keeps extracting as long as it’s in there, slowly when cold, so taste it and pull the bag when the beer is right.
Should I add oak during active fermentation?
You can, but most brewers wait until fermentation is finished. Then you know what the beer tastes like before the oak, and you can judge how much it has picked up.
Related guides
Barrel fermentation and aging, barrel-aged beer flavour, wild fermentation, keeping oxygen out.