Category Archives: Storage

Screwcaps and ageing

Screwcap closures have had some bad press, but in my opinion, any wine destined to be drunk within a year of production should be sold in a screwcap bottle.

Ch.Margaux is carrying out trials with screwcaps

Ch.Margaux is carrying out trials with screwcaps

What is good about screwcap bottles

  • The closure does not contaminate the wine. The wine may still be corked because of contamination during wine production, but at least the screwcap won’t have caused it.
  • Every bottle will be the same as the next. There are some caveats, and you should refer to a previous blog for further details. Every natural cork is different, whereas every screwcap closure is identical.

What is bad about screwcap bottles

  • Removing a screwcap just doesn’t have the same theatre as removing a cork. Sadly, I can’t think of any solution to this problem.
  • Production of ‘reductive’ chemicals in the wine because air is excluded. These are sulphur compounds which may be produced in the bottle because of the absence of air. These compounds disappear quickly after a bottle is opened, but can be excluded by modifying the winemaking process.
  • A little bit of oxygen appears to be necessary for a wine to age gracefully. Original screwcaps allowed almost no air to reach the wine.
  • Screwcaps were associated with cheap wine, so producers of quality wine tended to shy away.

New developments

  • The seal in a screwcap is provided by padding at the top. Different materials are being used for this padding, which allow different amounts of oxygen to pass through. This means that they can potentially be used for ageing fine wine.
  • The obvious thing is to try long term tests, and some tests were initiated in the 1980s in Australia. However, the prestigious Château Margaux in Bordeaux has started their own long term trials. Endorsement by one of the great old names in the wine business would make all the difference in the acceptance of screwcaps. Time will tell.

By choosing the correct seal, there will be screwcap closure for every wine, but it may take a while to prove the point.

Collecting wine and wine accessories

Collecting wine is an unusual form of collecting, as the stock is both perishable and delicious. Collecting accessories is more traditional.

Ch.Lafite 1982 - a speculator's wine

Ch.Lafite 1982 – a speculator’s wine

Collector vs investor

  • My definition of a wine collector is someone who enjoys drinking wine, and who has a particular interest in certain types of wine, or wine region. A collector may, or may not, make money out of their hobby.
  • An investor regards wine as a commodity, which they trade in the same way as stocks and shares. They may never set eyes on the stuff, or even like wine.

How to start a collection

  • Identify which types of wine you enjoy drinking.
  • Buy that wine, expanding to different producers within the region.
  • Buy the best wine you can afford. If a wine region becomes fashionable, it is always the top wines which appreciate the most.
  • If a wine increases in value, you have the option of selling it.
  • If the wine decreases in value, you can still drink it; an advantage over other types of asset.

Two examples:-

I particularly enjoy wine from two regions. Their contrasting investment performance shows the benefit of buying wine you enjoy:-

  • Burgundy, particularly Red Burgundy, and the Pinot Noir grape variety. This is a complex and fragmented region, producing fabulous wines and awful wines, and everything in between. There was a time when just about all the wines were affordable, but the top wine has now broken through the £10,000 ($16,000) a bottle barrier. This has dragged up the value of many other wines.
  • Rioja, is another region I have followed for many years. The best wines may not be as fine as a top Burgundy, but they represent very good value for money. There has only been a small appreciation in value with time, so I just drink and enjoy my Rioja.

Buying wine

The best sources of a wine are:-

  • The vineyard itself.
  • The main import agent in your country.

If you buy consistently from these sources, then you will continue to get an allocation, even if the wine becomes trendy and expensive. You can of course look out for deals from other sources, including the Internet and auctions.

Storing wine

Wine is a perishable commodity, and should be stored in suitable conditions – see a previous blog post. If you are going to keep a wine for several years, then you must do one of the following:-

  • Have it stored professionally, where they can maintain perfect conditions.
  • Store it at home in a specially designed wine storage device.
  • If you live in a temperate climate, then there are other options. A deep cellar is perfect, but you can also improvise to provide adequate conditions.

Provenance – who has owned the wine and where it has been stored – has a significant bearing on a wine’s value. It ensures the wine is in good condition, and is genuine. Sadly, fraud is an issue these days.

Wine accessories

Many types of accessory have been made over the years, and many of these are avidly collected.

  • Corkscrews. This are probably the most popular item, with amazing patented mechanisms. There are also exotic designs, many of the most popular being erotic.
  • Glass. Bottles, decanters, jugs, drinking glasses come in a vast array of designs, from beautiful Venetian glass to cruder items.
  • Wine coolers, wine labels, bin labels, coasters – the list goes on and on.….

Internet resources:-

  • The column to the right of this blog lists many useful wine-related sites.
  • Wine Collectionary – a useful source for collectable wine and wine accessories.

Visit the ‘Know Your Wine’ Facebook page, and ‘Like’ it to receive future posts.

Drinking wine on an aeroplane – a disappointing experience

Wines are usually disappointing if you drink them on a plane. The circumstances are unusual, with conditions affecting both the wine and the drinker.

wines to drink on an aircraft

wines to drink on an aircraft

What is unusual about aeroplanes:-

  • Aircraft are pressurised at the equivalent of around 8,000 ft altitude, which is about three-quarters of that at sea-level.
  • Air-conditioning reduces the humidity to around 10%, much lower than most people are used to.
  • There is a lot of vibration.

Affect on the wine:-

  • Low pressure reduces solubility of gases such as oxygen and carbon dioxide, and this reduces the wine’s freshness.
  • Red and white wines are usually served too warm, which has a significant influence on the taste and smell.
  • Wine is rarely served in a decent glass, and this has a negative influence.
  • Wines can be severely shaken up, which doesn’t help.

Affect on you:-

  • The low humidity has a direct influence on your nasal passages, and hence your sense of smell and taste.
  • You also salivate less in conditions of low humidity. Saliva moderates astringent tannins in wine, so a wine appears more astringent than normal in an aircraft.
  • Flying is stressful and tiring, and all this affects your senses.


The conditions tend to suppress the fruit and sweetness of a wine, and enhance any harsh acidity and tannin. So, wines need to be carefully selected to compensate for this.

Bottle variation

Bottles of the same wine may taste very different, and variations increase as a wine gets older. In fact one bottle of a mature wine may be wonderful, and the next over-the-hill. Why?

different bottle sizes

different bottle sizes

The blend
Virtually all wine is a blend from different barrels or vats. If the mixing vat is not big enough to take all the wine, then one batch may well differ from the next. So, there may be a difference before the wine is even bottled.

A particular wine may be bottled in batches rather than all at the same time. The fill levels, added sulphur dioxide, entrained oxygen, and gas injected above the wine may all vary at each bottling session.

The closure
Historically this was always natural cork. It is a fine closure, but every cork is different and will allow differing amounts of air to diffuse through. This causes bottles to mature at different rates. One big advantage of screwcaps is that each closure is the same.

Transport and storage
This is a major issue, and can completely destroy a wine.

  • Temperature – is covered in more detail by another post. If the temperature gets too high, the wine will be damaged, perhaps fatally. Cases of wine stored at different temperatures will mature at different rates.
  • ‘Lightstrike’ – damage by over-exposure to UV light.

Bottle size
The larger the bottle, the more slowly and gracefully a wine matures. This may just be because the gap between the cork and the wine is the same for a half bottle, a bottle or a magnum. Any air in that gap will be spread more thinly in a magnum than a half bottle, meaning that it will be oxidised more slowly.

Age of the wine
The older a wine, the more time there is for all these influences to take effect, and the higher the chance of one bottle being very different to the next.

Is there a perfect temperature for storing wine?

temperature and humidity recorder

temperature and humidity recorder

Wine is an organic living thing. The temperature a wine experiences can have a big influence on its quality.

So, is there a perfect temperature?
Time has shown that deep cellars in temperature parts of Europe are perfect for wine storage. A constant temperature of around 12°C (54°F) is ideal. A high humidity prevents the cork from drying out.

Increased temperature leads to increased reaction rates
Wine is a complicated mixture of chemicals, which react with each other. As the temperature rises, all of the reaction rates will increase, but some will increase more rapidly than others.

Increased temperature leads to new reaction products
As the temperature rises, new reactions will occur, which simply wouldn’t happen at 12°C. An example is the breakdown of aromatic chemicals in dry white wines. Unpleasant compounds are also produced.

Wines with low sulphites/sulphur dioxide
Natural wines with low levels of sulphites (sulphur dioxide) are increasingly popular. Sulphur dioxide serves two very useful functions:-

  • to limit oxidation of the wine.
  • prevent bacterial growth.

Both of these become much more of an issue as a wine’s temperature rises, and natural wines are particularly vulnerable.

Unfiltered wines
If the temperature gets too high, it is perfectly possible to restart fermentation . This causes plenty of problems.

What if the temperature is lower than 12°C (54°F)?
As the temperature decreases, the reaction rates slow down. So, a wine may not mature in the normal way, but at least it won’t go off. If a wine gets cold enough it may deposit white tartrate crystals, but these do no harm. The alcohol in wine depresses its freezing point, so it needs to be well below 0°C (32°F) before it even starts to freeze.

If you live in a climate where the temperature is above 25°C (77°F), and you don’t have dedicated wine storage, then please keep ALL your wine in a domestic fridge. You will have to remember to take the red out in good time before drinking it, but at least the wine will be in good condition.

Preserving wine once a bottle is opened

Once a bottle is opened, most wine has a very limited life. All but very mature wine will improve for a while when exposed to the air, but over time all wine will oxidise and become unpalatable.

The best thing to do with a bottle of wine is to drink it all at one sitting. If you fail to do that, then there are several options for preserving it in good condition for a few days.


Chilling any wine, including reds, will help to preserve them. All reaction rates, including oxidation by air, will decrease at low temperatures.

Vacuum systems

vacuum stopper

vacuum stopper

vacuum pump

vacuum pump

These pump air out of the bottle. The less air there is, the less oxygen is around to spoil the wine. The problem with hand-held systems is that you are likely to remove some of the desirable chemicals as well. Commercial systems claim to pump the air out more precisely, without affecting the volatile compounds in the wine.

Inert gas systems – hand-held

The gas cannister dispenses an inert gas on top of the wine; this is heavier than air and displaces it. Pouring wine from a bottle will agitate what is left in the bottle, and dissolve some more air into the wine. The inert gas will not keep the wine for prolonged periods, but it works well for several days.

Inert gas systems – commercial

These use an inert gas to force wine out of the bottle, and through a nozzle into a glass. No extra air is introduced into the bottle. Enomatic is the market leader, and their website provides more details. These systems allow restaurants, wine bars, and shops to sell wine by the glass, even if it takes weeks to empty the bottle.

Plastic film on top of the wine

A company called Wine Shield sells specially designed thin plastic film, which sits on top of the wine in a bottle. This aims to keep air away from the wine. I haven’t tried it, but it does sound plausible.

A simple and reliable approach

I pour wine into a smaller bottle, and fill it. Pour with care so as not to introduce too much air. Then stopper it and put it in the fridge. Depending on the wine, this is fine for a couple of days. It lasts longer if you squirt some inert gas above the wine.

Screwcaps versus cork for wine bottles

branded natural cork

natural cork

Natural cork provides a very good seal for a wine bottle, but a screwcap is potentially better still. There are pros and cons for each of them.

Sealing liquids

  • Cork has a unique cellular structure which allows it to be compressed, and then spring back to its original shape. This provides a very good seal to prevent wine from seeping out. It can still seep out if the bottle is overfilled, the cork damaged, or because of poor storage.
  • Screwcaps prevent any wine from seeping out.



Sealing gases

  • Cork. Oxygen can slowly diffuse through the cork into the wine. Some corks are more porous than others, and some have defects; this allows more rapid diffusion of oxygen into the wine, and more rapid ageing.
  • Screwcaps. The original screwcaps allowed almost no oxygen into the wine, and this may cause unpleasant odours to develop. Different seals are now available which allow controlled amounts of oxygen into the bottle.


  • Corks can be contaminated with TCA, a very small amount of which makes the wine undrinkable. Refer to this earlier post for details. This is cork’s biggest disadvantage.
  • Screwcaps do not contaminate the wine.


  • Cork. Bottles have to be stored with the wine in contact with the cork. If not, the cork dries out, and becomes a less effective seal. Rapid temperature fluctuations can cause a cork to move within the bottle neck, which can also cause sealing problems.
  • Bottles sealed with screwcaps do not suffer from these problems.

Long-term ageing

  • Cork has been used as a wine closure for centuries, and there is plenty of evidence that a good wine, with a good cork, stored in a good cellar, ages gracefully.
  • Screwcaps have been around for decades, and there is evidence that some wines age well. However, plenty more trials will be needed over many years, before everyone is convinced.


The scientist in me says that a screwcap with the right seal, is the perfect closure. No bottles will be contaminated, and every bottle in a batch will mature the same way. My heart however, would rather see a cork pulled from a fine bottle of wine, rather than someone crack open a screwcap.

Wine storage – what you need to know

Wine rack

A classic wine rack

Wine is alive, and there are two things which will kill or maim it in no time at all, they are direct sunlight, and temperatures above 25°C (77°F). Even if you are going to drink a wine soon after buying it, beware shops and restaurants where these conditions apply.

Light, aromatic wines are most susceptible, and heavy reds the least.

Sunlight has two harmful properties – ultraviolet light (UV) light, and radiation which heats what it shines on. UV light encourages the breakdown of many chemicals, and the oxidation of others. All this is bad news for the wine. Coloured glass provides some protection.

Temperature. High temperatures cause some chemicals to breakdown, and others to react rapidly. New and unpleasant compounds are also produced.

Avoid rapid changes in temperature as this can cause the cork to move within the bottle, and allow air in. This influx of air causes the wine to go off more quickly.

Ideal storage conditions are:-

  • Temperature:- 12°C to 13°C (54°F to 56°F).
  • Humidity:- 60 to 70%. If the cork dries out it will let air into the wine.
  • Horizontal:- the cork should be in contact with the wine, to prevent it from drying out.
  • Keep it in the dark. No sources of UV light or heat.