1. Wood as Data (Primary vs. Finish)
A label rarely says just "aged in oak". It names a primary maturation, the cask where the spirit spent most of its life, and often a finish, a shorter stay that adds a final accent. We store both separately, because a whisky matured in sherry and one merely finished in sherry are fundamentally different drinks.
Primary Maturation
Where the core character is built, often over many years.
Finish Maturation
A second cask that layers a recognisable accent on top.
Fill & Size
First-fill casks and small casks give more, and faster.
2. The Cask Families
Every cask we recognise belongs to one family. Open a family to light it up on the atlas.
"Fresh wood that has never held another liquid. The oak species and its origin set the tone: vanilla and coconut from American oak, spice and tannin from European oak, incense from Japanese oak."
Virgin Oak
New, unused wood. Releases intense vanilla, spice and raw timber notes in a short time.
European Oak
Tight-grained Quercus robur. Adds tannic grip, clove and dried fruit depth.
French Oak
Fine-grained oak from forests such as Limousin and Tronçais. Brings subtle spice and silky tannins.
Mizunara Oak
Rare Japanese oak, porous and hard to cooper. Known for sandalwood, incense and coconut.
Chinquapin Oak
An American white oak with a tighter grain than the classic bourbon barrel. Rounder sweetness, softer spice.
Garryana Oak
Oregon white oak from the Pacific Northwest. Smoky, savoury and spicy with a dense structure.
Scottish Oak
Native oak grown in Scotland. Rarely used, adding a robust, earthy and nutty spice.
"Native South American timbers, traditionally used for Cachaça. Each wood has its own chemistry, often far more aromatic than oak."
Amburana
Highly aromatic wood with notes of cinnamon, marzipan and tonka bean.
Bálsamo
Resinous and herbal, giving anise, clove and a balsamic character.
Jequitibá
A neutral, pale wood that softens the spirit without adding much colour.
Castanheira
Brazil nut wood. Contributes a gentle nuttiness and a light golden hue.
Amendoim
Peanut wood. Mild and soft, with subtle buttery and nutty tones.
Ipê
Dense hardwood that adds structure, a darker colour and dry woody notes.
"Casks seasoned with Spanish fortified wine from Jerez. The style of sherry decides whether the spirit turns rich and fruity or dry and nutty."
Sherry
Generic sherry seasoning when the style is not specified. Dried fruit, spice and a darker colour.
Oloroso Sherry
Oxidatively aged sherry. Walnut, raisin, leather and a full, rich body.
Pedro Ximénez
Intensely sweet sherry from sun-dried grapes. Fig, molasses and Christmas cake.
Fino Sherry
Pale sherry aged under flor yeast. Dry, saline and almond-like.
Amontillado Sherry
Starts under flor, then ages oxidatively. Hazelnut, toffee and a dry finish.
Manzanilla Sherry
Fino-style sherry from coastal Sanlúcar. Bright, briny and delicate.
Palo Cortado Sherry
A rare hybrid style with Amontillado's finesse and Oloroso's richness.
"Wines that are fortified, aromatised or naturally sweet. They leave red fruit, honey and a rounder texture."
Port
Fortified wine from the Douro. Red berries, chocolate and a plush sweetness.
Ruby Port
Young, fruit-forward Port. Cherry, plum and a pinkish hue.
Tawny Port
Port aged for longer in wood. Nutty, caramelised and drier than Ruby.
Madeira
Heated and oxidised fortified wine. Burnt sugar, acidity and dried orange peel.
Marsala
Sicilian fortified wine with notes of brown sugar, vanilla and stewed fruit.
Moscatel
Sweet Muscat wine. Floral, grapey and honeyed.
Tokaji
Hungarian botrytised wine. Apricot, honey and marmalade.
Vermouth
Aromatised fortified wine. Adds herbal, bitter and botanical layers.
Sauternes
Botrytised sweet white from Bordeaux. Honey, apricot and saffron.
Pineau
Pineau des Charentes, grape must fortified with Cognac. Fresh grape and soft fruit.
"Barrels that held still red or white wine. They bring tannin, berry fruit and acidity rather than sweetness."
Red Wine
Generic red wine seasoning. Red berries, tannin and a pink to copper tint.
White Wine
Generic white wine seasoning. Orchard fruit, freshness and light acidity.
Cabernet Sauvignon
Blackcurrant, cedar and firm tannins.
Syrah
Dark fruit with black pepper and a savoury edge.
Barolo
Nebbiolo from Piedmont. Rose, tar, cherry and grippy tannins.
Côte Rôtie
Northern Rhône Syrah. Violet, smoked meat and spice.
Bordeaux Wine
Classic Bordeaux blend. Cassis, graphite and structure.
Chardonnay
Buttery or fresh depending on style. Apple, citrus and a creamy texture.
Pinot Noir
Delicate red fruit, earthiness and silky tannins.
Amarone
Wine from dried grapes in Valpolicella. Raisin, cherry liqueur and richness.
"Barrels that first held another spirit or a beer. Bourbon is the industry's workhorse; the rest are finishing casks that add a recognisable accent."
Bourbon
Ex-bourbon American oak, the most common cask in the world. Vanilla, honey and butterscotch.
Rye
Ex-rye whiskey barrels. Spicier and drier than bourbon casks.
Rum
Ex-rum casks. Tropical fruit, molasses and brown sugar.
Cognac
Ex-Cognac French oak. Orchard fruit, floral notes and refined spice.
Brandy
Generic grape brandy casks. Dried fruit and soft oak.
Armagnac
Ex-Armagnac casks. Prune, rancio and a rustic depth.
Calvados
Ex-Calvados casks. Baked apple and pear.
Grappa
Ex-grappa casks. Grape skin, herbs and a lively edge.
Tequila
Ex-tequila casks. Cooked agave, pepper and citrus.
Mezcal
Ex-mezcal casks. Smoky agave and an earthy note.
Stout Beer
Seasoned with stout. Roasted coffee, cocoa and a creamy texture.
IPA Beer
Seasoned with IPA. Hoppy citrus, pine and floral bitterness.
Beer
Seasoned with a beer of an unnamed style. Malty sweetness and a soft bready note.
Peated
Casks that previously held peated whisky. Add smoke to an unpeated spirit.
"Size changes the ratio of wood surface to liquid. Smaller casks work faster and harder; larger casks are gentler and slower."
Blood Tub
Around 40 litres. The smallest common cask, for very rapid wood influence.
Quarter Cask
Around 50 litres. Intense extraction in a short time.
Barrique
Around 225 litres. The Bordeaux wine standard.
Hogshead
Around 250 litres. Often rebuilt from bourbon barrels with extra staves.
Puncheon
Around 450–500 litres. Wide and squat, often used for rum or sherry.
Butt
Around 500 litres. The traditional sherry cask, slow and gentle.
3. Reading the Cask Line
Producers describe the same barrel in dozens of ways: "ex-Oloroso butts", "Jerez sherry casks", "PX seasoned". Our engine maps every synonym to one canonical cask, so a search for Pedro Ximénez finds them all. When a source states that a cask is first-fill, we keep that detail, because a first-fill cask gives far more of its previous liquid than a cask on its third or fourth cycle.
Example
"Matured in ex-bourbon barrels and finished for 18 months in first-fill Oloroso hogsheads" becomes:
4. How We Use It
In Explore
The cask filter searches primary and finish maturation together, so "Sherry" returns both sherry-matured and sherry-finished bottles. Every drink card shows its primary cask, its finish and the fill where known.
In AI Insights
Insights segment the market by primary and finish cask, measure how each cask shifts the flavor profile against its category, and link a drink to an insight when its casks match the targets.
Curious what each wood actually tastes like? Read Cask Influence.