Methodology
The Cellared Ageability Index (CAI)
The Cellared Ageability Index is a 10-factor model. This page is the documented methodology: what we measure, where the data comes from, what the model cannot know, and how we keep it honest.
- Version
- CAI v1.0
- Last reviewed
- Published
- Author
- Carson Smith, WSET L3
Key takeaways
- CAI returns a four-point window (open, peak start, peak end, close), not a single year.
- 10 weighted factors: tannin, acid, alcohol, residual sugar, body, oak, varietal curve, vintage modifier, producer house style, closure.
- Vintage modifiers sourced from Decanter, Wine Spectator, Wine Advocate, Vinous and refreshed annually.
- Two same-varietal same-vintage wines can differ by 15+ years on CAI; producer house style and closure are large modifiers.
- Low-confidence projections return a wider range with a caveat rather than a precise number.
Why drinking windows are hard
A drinking window is not a single point. It is a range with a shape: too young, approaching peak, peak, mature, past peak. The shape depends on the structure of the wine, the conditions of the vintage, the philosophy of the producer, the varietal genome, and the closure under the foil. Every cellar tool that tries to give one number is flattening four dimensions into one.
Cellared keeps the dimensions. The model returns a four-point range (open, peak start, peak end, close) rather than a single answer. That is the only honest way to project age-worthiness.
The 10 factors
Tannin structure
Phenolic load drives age-worthiness. We score on a 1 to 10 scale calibrated against standard tannin descriptors, with type weighting (skin tannin, seed tannin, oak tannin treated separately). High-tannin reds like Nebbiolo and Cabernet Sauvignon get longer projected windows; low-tannin styles like Pinot Noir lean on other factors.
Total acidity
Acid is the structural backbone that lets wine survive long aging. Riesling, Champagne, and Burgundy at the high end. Soft-acid Mediterranean whites at the low end. Acidity calibrated by varietal norm and adjusted for vintage thermal index.
Alcohol
Used as a stability and balance signal, not a positive driver. Wines under 12 percent or over 15 percent face shorter aging trajectories unless other factors compensate. Fortified wines use a separate model.
Residual sugar
Botrytis dessert wines, late-harvest, ice wine, and Tokaj all follow distinct aging curves. RS is a preservative; sweet wines built for aging are scored on their own track and blend back into the main model.
Body and extract
Concentration of dissolved solids predicts how a wine evolves. Light-bodied, fresh-fruit styles show short windows. Concentrated, low-yield wines from old vines or heat-stressed sites carry deeper material and longer windows.
Oak treatment
New oak percentage, barrel age, toast level, and elevage duration all factor in. Heavy new oak adds tannin and slows early integration. Stainless or neutral oak shifts the curve toward earlier drinkability.
Varietal aging curve
Each varietal has a baseline aging trajectory built from decades of professional tasting data. Cabernet Sauvignon, Nebbiolo, Sangiovese, Riesling, Champagne, and Tokaj all have distinct curves. The varietal curve is then adjusted by the wine-specific factors above.
Vintage modifier
Every region gets an annual vintage modifier sourced from professional vintage reports (Decanter, Wine Spectator, Vinous, Wine Advocate, regional councils). The modifier is a numeric coefficient that scales the projected window for that region and year. Updated annually.
Producer house style
Two wines with identical varietal and vintage from neighboring producers can age very differently. We track house style at the producer level: extraction philosophy, oak handling, ripeness preference, traditional vs modern stylistic positioning. Wines from collectible producers known for longevity get a calibrated lift.
Closure type
Cork type (natural, technical, DIAM, screwcap, glass), oxygen transmission rate, and year-of-bottling closure quality all influence the upper bound of the drinking window. Screwcap whites and DIAM-closed reds generally hold longer than natural cork.
Where the data comes from
Cellared maintains a master wine database joined against producer profiles, regional vintage modifier tables, and varietal aging curve coefficients. Wine-level data comes from professional tasting notes, technical sheets, and our own enrichment pipeline. Vintage modifiers are sourced from published professional vintage reports and updated annually.
Once you log a bottle as consumed and rate the experience, your own consumption data becomes a calibration signal for your personal windows. This is what the Pro tier learns from over time.
What the model does not know
Your specific storage conditions
We assume wine is stored at 55F and 70 percent humidity, dark, vibration-free. If you store at 65F or in fluctuating conditions, your real drinking window is shorter than what we project. We surface this as a caveat in the app and flag temperature-sensitive wines.
Individual bottle variation
Even from the same case, two bottles can age differently because of cork lottery and microclimate inside the rack. The model gives you a window for the wine. Your specific bottle may peak earlier or hold longer.
Your palate preferences
The model targets a balanced sweet spot between primary fruit and secondary development. If you prefer your wines on the younger, fruitier side, drink at the early end of the window. If you prefer tertiary notes, drink at the late end. The Pro tier learns your preference over time and shifts your personal windows.
Wines with insufficient data
When a wine lacks enough structural data to score confidently, we flag the projection as low confidence. We would rather show you a wide range with a caveat than a precise number we cannot stand behind.
How we calibrate
Annual vintage refresh
Vintage modifiers are updated each year as professional reports land. The model re-runs against published windows to spot drift. Sessions are run for Bordeaux, Burgundy, Rhone, Tuscany, Piedmont, Champagne, Napa, Sonoma, Rioja, Mosel, Australia, and South America.
Calibration sessions
We run dedicated calibration sessions for collectible categories that the standard model historically underweights: Champagne (long-tirage and disgorgement variability), Rioja Gran Reserva (extended barrel and bottle aging), DRC and Leroy (producer-driven longevity premium), Penfolds Grange (Australian Shiraz with cellaring intent), Vega Sicilia (atypical varietal blend with multi-decade aging).
Sources and further reading
Decanter vintage reports, region-by-region annual
Primary source for vintage modifiers.
Wine Spectator vintage charts, Wine Advocate vintage charts, Vinous vintage reports
Cross-reference for vintage modifier calibration.
Master of Wine theses on aging and tannin development
Academic grounding for tannin and acid scoring.
Wine Folly aging research and charts
Reference for varietal aging curves at the consumer level.
Frequently asked
Is my wine ready to drink right now?
Cellared returns a four-point window for every bottle: open, peak start, peak end, close. If today's date is past the open year and before the peak start, the wine is approachable but still developing. Peak years are the recommended drinking window. After the close year, the bottle is at risk of decline.
Can I age my wine past the projected window?
Sometimes. Storage at 55F with stable humidity, low light, and minimal vibration extends the window. So does a high-end closure (DIAM, glass, screwcap for whites). The CAI projection assumes ideal storage and average bottle variation. Well-stored collectible bottles can sometimes outlive the projected close year.
Should I open this wine tonight?
Use Quick Pick in the app, which filters your cellar by tonight's window and your meal context. From the methodology: a wine inside its peak range and paired with a compatible food is the right open-tonight candidate. A wine still in its pre-peak phase needs more time unless the occasion calls for fruit-forward expression.
What does a wine taste like at peak?
Peak is when primary fruit, secondary development (oak, lees, malo), and tertiary notes (forest floor, dried fruit, tobacco, leather) are balanced. Before peak: primary fruit dominates and structure feels grippy. After peak: fruit fades and tertiary notes take over until they hollow.
Why does Cellared sometimes show a wide window?
When wine-specific structural data is sparse, CAI returns a wider range with a low-confidence flag rather than a precise number it cannot defend. A four-year window means high confidence. A ten-year window means the model is honest about uncertainty.
How is CAI different from a generic varietal aging chart?
Generic charts assume a Cabernet ages like a Cabernet. CAI scores the actual wine: producer house style, vintage modifier, oak treatment, closure quality, residual sugar. Two Cabernets from the same vintage can differ by 15+ years on CAI even though a varietal chart would show one number.
How often is CAI updated?
Vintage modifiers are refreshed annually as Decanter, Wine Spectator, Wine Advocate, and Vinous publish vintage reports. Producer house style data is updated when a winemaking change is documented. Major methodology revisions ship as new versions (current: CAI v1.0, reviewed 2026-05-15).
How this is versioned
The model is versioned and dated so it stays stable to reference: the current release is CAI v1.0, last reviewed 2026-05-15. The version changes only when the model itself changes; annual vintage-modifier refreshes update the reviewed date without incrementing it.
See it on a bottle
Drinking windows on every bottle in your cellar. Try it on a wine in the guide.
Browse the Wine Guide