What have croissants and coffee got to do with it?
A recent road trip to Bordeaux, fuelled largely by coffee and the (very) occasional croissant, reminded me how small choices in roasting or baking can transform simple ingredients into something layered and complex. The same is true of wine: beyond the vineyard’s fruit-driven primary aromas and the winemaking-led secondary aromas discussed previously lie the more elusive tertiary flavours, revealed only with time in barrel or bottle.
As harvest gathers pace, crews working long shifts in vineyard and cellar are often fuelled by caffeine well into the early hours. The relentless cycle of pick, press, clean, repeat can leave even the most seasoned teams running on autopilot. Yet the true reward lies down the line, when patient viticultural and winemaking choices reveal themselves in bottles of depth and character.
In reds, vibrant berry evolves into dried fruit, leather, cedar and tobacco. Whites shift from citrus to honey, toast, nut and petrol. Sparkling wines gain richness from extended lees ageing, delivering brioche, hazelnut and cream – a hallmark of English sparkling wines, where crisp acidity sets these tertiary notes in striking balance.
These changes arise from a blend of processes:
- Oxidation (nutty, caramelised notes),
- Tannin and pigment polymerisation (softer mouthfeel, brick-red hues),
- Maillard reactions in sparkling wines (biscuit, roasted character),
- Wood interactions (spice, vanilla, toast).
While oak remains the classic tool, amphorae, staves and alternative vessels offer different balances of oxygen and flavour. Just as important is the closure, whose oxygen transmission rate determines whether a wine ages gracefully or prematurely oxidises. For producers, the challenge is part science, part patience. Trials with vessels, closures and ageing regimes are essential, but so too is knowing the market.
While the influence of winemaking practice on tertiary character is well documented, recent studies now highlight how vineyard management – from water and nitrogen balance to canopy shading and harvest maturity – might influence how wines develop both in barrel and bottle. Opposite, I’ll explore some of the most interesting findings and reviews, drawing together current understanding and pointing to the new research areas being investigated.
Vineyard foundations: setting up the future
The vineyard does more than shape primary fruit – it determines the precursors that later unfold into tertiary complexity. Balancing the stresses the changeable weather brings is critical for vineyard managers to proactively influence the wine style, as the saying goes you make good wine from good grapes. Some of the recent papers I have looked at highlight how management in the vineyard can affect the wines outcome.
Water and nitrogen balance
Studies in Bordeaux show that moderate water deficit can enhance the eventual “ageing bouquet” of truffle, cedar and undergrowth in reds (Picard et al., 2017; Le Menn et al., 2019). By contrast, excess nitrogen has been associated with elevated dimethyl sulphide (DMS) in aged wines – intriguing in trace amounts but overpowering when dominant (Samaniego Solis et al., 2024).
In the UK, assessing yeast-assimilable nitrogen (YAN) is not yet routine at many vineyards, and growers often work with rules of thumb rather than detailed laboratory data. Much of the available nitrogen is rapidly consumed during the lag phase of fermentation, meaning decisions made in the vineyard carry long-term consequences.
This season has provided a useful contrast: this sun-drenched summer of 2025 has sharply differed from the cooler, wetter conditions of last year. Sunshine and warmth alter vine water stress and nitrogen uptake, shaping the pools of precursors that will only reveal themselves years later in the tertiary complexity of the finished wines.
Light and canopy management
As discussed in a previous article, sunlight exposure drives carotenoid breakdown, feeding norisoprenoid precursors such as TDN and β-damascenone. These compounds only become apparent with bottle age, contributing the familiar petrol or honeyed notes seen in Riesling and Chardonnay. While Riesling plantings remain limited in the UK, it shares a genetic pathway with the more widely planted Bacchus, meaning similar mechanisms may influence ageing potential here.
Trials in Franciacorta showed that shading nets reduced norisoprenoid accumulation, while heavy leaf removal increased it (Ghiglieno et al., 2023). Complementary Riesling studies using photoselective shading confirmed the direct impact of vineyard light exposure on TDN levels (Grebneva et al., 2022).
Harvest maturity and amino acids
Amino-acid levels at harvest influence Strecker aldehydes, which drive nutty, malty and meaty complexity over time (Bueno et al., 2018). Work on Moristel (Arias-Pérez et al., 2022) and Savvatiano (Miliordos et al., 2025) shows how vintage and maturity shape amino-acid pools, steering long-term flavour outcomes.
Takeaways for growers
- Aim for moderate water stress, not extremes.
- Manage nitrogen carefully to avoid runaway DMS.
- Canopy management in hot years to temper TDN in whites.
- Monitor amino acids/YAN at harvest for age-worthy programmes.
Winery influences; orchestrating to greatness
Once fruit arrives in the cellar, winemaking choices set the trajectory for how vineyard precursors are expressed and evolve.
Oxygen management
In barrel, micro-oxygenation builds aldehydes and polymerises tannins, softening colour and mouthfeel. At bottling, however, oxygen becomes a risk factor. Excess dissolved oxygen accelerates decline, while too little can stall development. Closure research (Suhas et al., 2025; Mota et al., 2025) highlights how oxygen transmission rate (OTR) differs between corks and screwcaps, shaping long-term evolution.
Vessel choice
Oak species and toast levels contribute distinct signatures: French oak subtle spice, American oak vanilla and coconut, acacia and chestnut their own typicity. Amphorae and concrete offer slow oxygen ingress without oak overlay. Each vessel is, in essence, a different “brew method” for grape precursors.
Lees and Maillard reactions
In sparkling wines, extended lees ageing promotes nutty, biscuity tertiary character through Maillard chemistry between amino acids and sugars (Charnock et al., 2022; 2023). Tirage yeast, tirage closure and dosage sugar type all modulate the balance, offering precise control over tertiary depth.
Closures and ageing arcs
Far from neutral, closures shape trajectory. Long-term OTR and NMR studies (Leleu et al., 2025; Suhas et al., 2025) confirm corks and screwcaps age differently, with substantial stopper-to-stopper variation. Matching closure choice to intended release timing is critical.
Takeaways for winemakers
- Select closures by OTR, not cost alone.
- Trial vessel diversity to fine-tune tertiary development.
- Use lees time and dosage experiments to modulate sparkling complexity.
- Track dissolved oxygen carefully at bottling – small margins matter over years.
In conclusion
Just like the boulangerie and café there’s a fine line between delicious and overdone, wine’s tertiary character rests on many small decisions: vineyard water stress, nitrogen status, canopy exposure, harvest maturity, oxygen management, vessel choice and closure. Each step contributes to whether a wine evolves towards earthy depth, nutty savour or honeyed elegance.
For drinkers, the reward is the complexity of a mature wine. For growers and winemakers, the process is disciplined and patient, demanding long-term vision rather than instant gratification.
It’s worth remembering that aged wines also require capital, storage, and consumers willing to wait. While the current market often prizes freshness and immediacy, cycles change – as with fashion, what was once overlooked can return as cool, reinvented and reinvigorated. Tertiary aromas are part of that rhythm: the proof that flavour is never an accident, but the slow unfolding of time, choice and craft.
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