The mystery of minerality

In the July edition of Societynews we answered a member’s question on the term ‘minerality’. Here Master of Wine and scientist Caroline Gilby examines the subject in more detail

Back in the late 1990s, I recall doing some translation work for a Chablis producer when I insisted that ‘the typicity of the minerality’ was a meaningless phrase in English. The word ‘minerality’ barely appeared in wine language back then and it didn’t appear in Emile Peynaud’s legendary wine tasting bible The Taste of Wine published in the 1983. Today, though, you won’t read many wine descriptions before the words ‘mineral’ or ‘minerality’ crop up (‘mineral’ appears more than 50 times if you do a search on The Wine Society website, for example). It’s usually a positive cue for a quality wine with a sense of place or terroir and often linked closely to a specific soil or rock type.

> Classic 'mineral' wines to taste

But does minerality come from the soil?

There is an implication that this mineral quality must somehow come from the vineyard and the soils or bedrock, but try as they might scientists cannot find any sort of mechanism for this. The thing is that plants are very good at absorbing what they need and nothing more. And it’s important to understand that in fact what they take up from the soil through the roots has to be dissolved in water, meaning very simple ions, and these have no taste at the levels measured in wine. There’s a good paper by Alex Maltmann of Aberystwyth University on this for anyone wanting to delve deeper. It makes no difference whether a calcium ion, for instance, comes from chalk, limestone, clay or any other sort of bedrock – it’s still the same tasteless cation. And there’s no mechanism for complex or crystalline minerals to be taken up by plant roots and end up in the grapes.

At this point it’s worth a couple of definitions. The International Mineralogical Association definition is ‘A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes.’ It is also naturally occurring (so not man made), inorganic, solid with a definite chemical composition and ordered internal structure. In contrast, rocks are disordered and are a mixture of minerals. Examples of minerals include things like calcite (that is important in limestone rock), halite (rock salt) and sulphur, while rocks include chalk, slate, shale, basalt and many more.

Distinctly different: halite (rock-salt) is a mineral not a rock

Distinctly different: halite (rock-salt) is a mineral not a rock

Do we all mean the same thing when we use the term ‘mineral’?

The use of the word ‘mineral’ has become so widespread that various researchers have tried to identify if there is a detectable cause in wine and indeed if there is any unity between tasters in what the concept of ‘mineral’ or ‘minerality’ means. One recent paper by Parr et al in New Zealand tested two groups of tasters from France and New Zealand respectively to identify mineral characters in samples of sauvignon blanc. Descriptors like citrus, flinty and chalky were linked to minerality in both groups while tropical notes like passion fruit were negatively linked to minerality. Interestingly, in this group the French tasters relied more heavily on the nose to evaluate wines than the New Zealand ones though there was largely agreement about key descriptions. Parr has also pointed out that the rise of the term ‘minerality’ has also been paralleled by the rise of screw cap use in New Zealand.

Are some grapes more likely to be described as ‘mineral’?

Chardonnay, one of the grapes more prone to show mineral characteristics Chardonnay, one of the grapes more prone to show mineral characteristics

If you ever get the chance to do a horizontal tasting across wines from different soil types from a single producer, it’s clear there are differences and therefore also clear that there’s a gaping chasm between the art and scientific understanding of this aspect of wine. But scientists are working hard to try and tackle this. A recent study in Spain (by Outlook Wine and Excell Iberica) entitled Minerality in Wines found that the chemical composition of wines and perception of mineral characters are not linked to minerals in vineyard soil. The team also looked at the sensory basis for mineral character in wine and came to some conclusions. They found that certain grapes are more prone to showing mineral character including chardonnay, chenin blanc, albariño and sauvignon blanc, and in reds syrah and pinot noir with cabernet franc, nebbiolo and cabernet sauvignon to a lesser extent.

Cool climate means more incidences of ‘minerality’?

There was also an association with expressing ‘minerality’ if grapes had been grown in cold or cool climates; harvested earlier rather than fully or over-ripe; if the wines showed high acidity/low pH and had been made using reductive techniques (ie minimal exposure to oxygen) and had higher levels of free sulphur dioxide. They also found that there had to be an absence of highly aromatic compounds, particularly terpenes (responsible for key aromas in lemons, lavender and pine, for instance) and fruity esters. The researchers also found the presence of higher levels of an acid called succinic acid (which is produced by the yeast metabolism during fermentation) and has a salty taste is directly associated with the concept of minerality in some wines. However, careful research to define a group of wines as ‘mineral’ and then to analyse them, did not find any single compound consistently linked to this characteristic.

Vineyard characteristics could have some influence

What is clear is that this is a complex picture and there are almost certainly links with what is going on in the vineyard and its soils, even if the soils are not involved directly. For instance, stress in the vineyard caused by lack of water (on sandy, gravelly or rocky sites, for example) can cause changes in juice composition that may lead to ‘mineral’ characters. Another soil factor is that infertile soils with low nitrogen (limestone soils are often low in fertility, for instance) may mean low nitrogen in the juice which can force yeast to metabolise more sulphurcontaining compounds, leading to more reductive, struck-match/flinty characters associated with ‘mineral’ descriptions. This suggests that geological/climatic factors are involved but doesn’t show any firm link with an identifiable chemical. The process of fermentation plus clarification and stabilising wine also affects the composition of wine and thus its final taste and possible perceptions of ‘minerality’ too.

Stress in the vineyard due to lack of water may lead to ‘mineral’ characters (Rocky vineyard, Croatia)

Stress in the vineyard due to lack of water may lead to ‘mineral’ characters (Rocky vineyard, Croatia)

So, the answer doesn’t just lie in the soil then?

So it appears that the phenomenon of ‘minerality’ is complex and most likely to be an indirect effect of grape growing and also winemaking. But it is not in any provable or literal way a taste of actual rocks or minerals found in a vineyard. Nonetheless, the word ‘mineral’ has become very fashionable and a handy shorthand for implying quality, elegance and provenance. I don’t see the word going out of fashion anytime soon.

Caroline Gilby: Master of Wine

Caroline Gilby MW Caroline Gilby MW:
Master of Wine

Caroline Gilby is a Master of Wine and a scientist by training. She is a wine writer with a passion for the wines of Central and Eastern Europe and contributes to several wine books, magazines and websites.

> Classic 'mineral' wines to taste

> Winemaking: The Importance of the Soil

> Read other articles by Caroline Gilby MW

Members' Comments (0)

There are no comments for this article.

Want more inspiration?

Sign up for a carefully-curated selection of recipes, guides, in-depth expertise and much more.

Our website uses cookies with the aim of providing you with a better service. By using this website you consent to The Wine Society using cookies in accordance with our policy.


4.4. Cookie Policy

By using The Wine Society website, you agree to cookies being used in accordance with the policy outlined below. If you do not agree to this, you must alter your browser settings to turn off cookies or block those types which are unacceptable to you or cease using the website.

The Wine Society uses cookies to enable easy navigation and shopping on the website. We take the privacy of all who use our website very seriously and ensure that our use of cookies complies with current EU legislation. The following guide outlines what cookies are, the types of cookies used on The Society's website and how they work.

You may alter your browser settings to turn off cookies or block those types which are unacceptable to you, but this will cause difficulties when accessing and using some areas of the site. Instructions on how to do this can also be found below.

4.4.1. What are 'Cookies'?

  • Most major websites use cookies.
  • A cookie is a very small data file placed on your hard drive by a web page server. It is essentially your access card, and cannot be executed as code or deliver viruses. It is uniquely yours and can only be read by the server that gave it to you.
  • Cookies cannot be used by themselves to identify you.
  • The purpose of a basic cookie is to tell the server that you returned to that web page or have items in your basket. Without cookies, websites and their servers have no memory. A cookie, like a key, enables swift passage from one place to the next.
  • Without a cookie every time you open a new web page the server where that page is stored will treat you like a completely new visitor.
  • More recently, cookies have also been used to collect information about the user which allows a profile of their preferences and interests to be created so that they can be served with interest-based rather than generic information about available goods and services.

4.4.2. How do Cookies help The Wine Society?

Cookies allow our website to function effectively. Cookies also help us to arrange content to match your preferred interests more quickly. We can learn what information is important to our visitors, and what isn't.

4.4.3. How does The Wine Society use cookies?

The Wine Society does not accept advertising from third parties and therefore, as a rule, does not serve third-party cookies. Exceptions to this include performance/analytical cookies (see below), used anonymously to improve the way our website works, the provision of personalised recommendations, and occasions when we may team up with suppliers to offer special discounts on goods or services.

The Society uses technology to track the patterns of behaviour of visitors to our site.

4.4.4. What type of cookies does The Wine Society use?

We use the following three types of cookies: Strictly Necessary Cookies
These cookies are required for the operation of our website, enabling you to move around the website and use its features, such as accessing secure areas of the website. Without these cookies, services like shopping baskets or e-billing cannot be provided. Under this heading, we currently use the following cookies:

  • Authentication Cookie and Anonymous Cookie
    These cookies remember that you are logged in to your account – without them, the website would repeatedly request your login details with each new page you visit during your time on our website. They are removed once your session has ended.
  • Session Cookie
    These cookies are used to remember who you are as you use our site: without them, the website would be unable to tell the difference between you and another Wine Society member and facilities such as your basket and the checkout process would therefore not be able to function. They too are removed once your session has ended. Functionality & Targeting/Tracking Cookies
These cookies are used to recognise you when you return to our website and to provide enhanced features. This allows us to personalise our content for you. Under this heading, we currently use the following cookies:

  • Unique User Cookie
    This cookie is used to:
    • store your share number in order to identify that you have visited the website before. Without this cookie, we would be unable to tell whether you are a member or not.
    • record your visit to the website, the pages you have visited and the links you have followed. We use this information to make our website, the content displayed on it and direct marketing communications we may send to you or contact you about more relevant to your interests.
    • This cookie expires after 13 months.
  • Peerius Cookies
    These third-party cookies are used to provide you with personalised recommendations based on your purchase and browsing history. They expire within 4 hours of your visit. Performance/analytical cookies
These cookies collect information about how visitors use a website, for instance which pages visitors go to most often, and if they get error messages from web pages. These cookies don't collect information which identifies a visitor. All information these cookies collect is aggregated and therefore anonymous. It is only used to improve how a website works. Under this heading, we currently use the following cookies:

  • Google Analytics Cookies
    These are third-party cookies to enable Google Analytics to monitor website traffic. All information is recorded anonymously. Using Google Analytics allows The Society to better understand how members use our site and monitor website traffic. Authentication Cookie
In order for us to ensure that your data remains secure it is necessary for us to verify that your session is authentic (i.e. it has not been compromised by a malicious user). We do this by storing an otherwise meaningless unique ID in a cookie for the duration of your visit. No personal information can be gained from this cookie.

4.4.5. How do you turn cookies off?

All modern browsers allow you to modify your cookie settings so that all cookies, or those types which are not acceptable to you, are blocked. However, please note that this may affect the successful functioning of the site, particularly if you block all cookies, including essential cookies. For example, In Internet Explorer, go to the Tools Menu, then go to Internet Options, then go to Privacy. Here you can change the rules your browser uses to accept cookies. You can find out more in the public sources mentioned below.

4.4.6. Learn more about cookies

4.4.7. Changes to our cookie policy

Any changes we may make to our cookie policy in the future will be posted on the website and, where appropriate, notified to you by email. Please check back frequently to see any updates and changes to our cookie policy.