Cellaring Wine - All Your Questions Answered
As you might have seen on our socials or even in your inboxes, Dewey Station Wines have decided to start a yearly tradition of releasing a few of our best kept bottles in September.
Due to some of our first vintages being ultra-small runs we only have a limited quantity to share. That’s where our wine club members step in, they’ll have exclusive access to purchase these beauties each year. Want in? Join the club!
Here, we’re going to discuss a little more about why we cellar wines and drive ourselves mad attempting to be patient enough to pop the cork at the very right moment.
How Does a Wine ‘Age’?
Wine ages through the slowed process of oxidation (you heard that right!).
With corks, screwcaps, or glass tops all wine closures have an oxygen transfer rate due to their porosity as well as the limited oxygen left in the bottle during bottling. For instance natural cork tends to have a higher OTR than manufactured screwcaps. This is why a lot of high tannin Old World reds (French Bordeaux, Italian Barolo, Spanish Rioja, etc.) will usually be enclosed via cork, also to follow the centuries of tradition beforehand, and light, bright New World Wines (New Zealand Sauvignon Blanc, South African Pinotage, Australian Grenache, etc.) will usually have screwcaps.
Another note between cork and screwcaps is the ever ongoing and fiery debate around which one is ultimately better - we’ll let you decide!
Cellaring a wine will also dramatically affect the colour, deepening into a yellow or deep amber for whites, and lightening to a brickish or orange-red for a red wine. More on that later...
What Wines Cellar Best?
Short answer, wines that have structure.
White wines or red wines that have either high acid or medium to high tannins.
Most wines can age, it just depends on how long. For example, if Shiraz and Cabernet Sauvignon are made with extended time on skins during fermentation (more info can be found on our socials series Wine Talk Wednesday: Skin Contact and Tannin) and adequate time in oak - this will produce a wine with high enough tannin and acid to develop for 10 to 20 sometimes even 30+ years. Whereas Grenache and Pinot Noir that have lower tannins naturally and tend to spend less time in oak generally have a 5 to 10 year window before losing too much fruit and tasting ‘dried out’ or off.
I know what some of you might be thinking, but how come white wines can age if they have little or no tannin? That’s where acid steps in, Riesling in partticular is naturally high in acid even if sweet (how the Germans like it!) and some Semillons and Chardonnays can also be laid down for 10+ years.
So What Actually Happens? (Prepare to get science-y!)
Acid
Natural acid is used as a ‘freshness preserver’, slowing down the chemical reactions responsible for way a wine changes over time in the bottle. Chemical reactions of acids and alcohols slowly bonding over time facilitated by the low level oxidation create new molecules called ester. These good ol’ aunt esters transition those bright citrus notes into the more mellowed, sometimes creamy honey, nuts, and dried fruit characters we love in a richer white. By ’softening’ these acids through time white wines that began as sharp, linear and usually best super chilled mature into broader, opulent and palate-filling wines better served only lightly chilled.
Tannin
Here’s where we really get into the beakers and lab coats!
Facilitated by slow oxidation, over time tannins shift from smaller polyphenol molecules binding together to create longer chains - this is called polymerisation. So if the tannins are still there, just changed, how come the wine feels softer? Well, as the chains grow larger they lose solubility and ability to bind with the proteins in your saliva so instead of feeling ‘grippy’ on the palate they take on a velvety smoothness.
This also explains why high tannin red varieties can tend to age longer than lower tannin varieties - there’s just more tannin chains to bond!
Colour
Red Wine
Youthful red wines gain their colour from pigments called anthocyanins which fade and degrade over time. These fun little compounds can also be found in berries, flowers, and vegetables like blueberries, red cabbage, and butterfly peas. Anthocyanins also undergo polymerisation with tannins, becoming chains so heavy they drop to the bottom of the bottle as sediment. (That chunky stuff in the last pour of an older bottle, yum!) As this happens your wine will turn from those vibrant reds and purples into brick-red and orange hues.
White Wine
Phenolics (the tannins of white wines), which are responsible for mouthfeel, colour, and flavour, do oxidise over time. Given great cellaring conditions and the correct type of wine - these will slowly shift from pale straw to deep gold or amber colours. If you’ve ever forgotten an opened bottle oif white wine before, you may have seen a fast-tracked version of this process as miore oxygen was available.
Does Temperature Actually Matter?
Absolutely!
After deep diving into the science behind how and why a wine changes over time, temperature can either accelerate or slow down this process dramatically!
Heat directly speeds up the rate at which these chemical reactions occur, doubling by roughly every 10 degrees warmer. If storing in a space that exceeds 21 degrees you might see risks of a seal failure as the liquid expands, vinegar-like or ‘cooked’ flavours.
The opposite can occur when the storage space is too cold, stunting the developent of the wine. This usually happens at and below 7 degrees celcius. There’s an additional risk of further oxidation if sealed with cork as naturally the material contracts in cooler temperatures.
The best way to keep your wine safe, sound, and comfortable during it’s aging journey is at a constant temperature. The ideal is 12 to 13 degrees, but in Australia that can be pretty hard to manage without a specific wine fridge. So, top tips are a space that stays relatively cool and constant, think a bathroom or walk in robe that has no outside walls or is tiled, and keep the bottles away from direct light (yes, UV affects a wine too - how precious!)
Made it to the end?
Now you’re equipped with info that will impress any dinner party!
Wine Club Members, feel free to whip out these fun facts when you share you’re Museum Release nabs with friends.
Want to read more?
Here’s a couple of our fav articles:
https://winefolly.com/tips/white-wine-aging-chart-best-practices/
https://winecompanion.com.au/articles/news/what-to-cellar-and-why
https://www.vintec.com/en-au/expert-advice/cellaring-wine/facts-about-wine-cellaring/