Truffle information for the media

So, you’re writing about truffles. Thank you on behalf of the Australian Truffle Growers Association (there’s a bit about us on this page).
We realise you are on your usual deadline, so a Google search and cut and paste is your prime research tool. Which is fine if you understand what you’re talking about, but if you haven’t tried eating truffles and have been given wildly different information to make sense of, it is hard.

If that’s you, this page is here to help. We’ve seen lots of stories where we thought we’d shared the right information that gets mangled on publication and laughed at.

You’re welcome to cut and paste and if you can wangle it, a mention of the Australian Truffle Growers Association website is all we’d like in return especially for online stories. While we will occasionally wax lyrical about this product we love, this page is concise as we can make it. There are some expandable sections with links to other material if you need it.

We are acutely aware that information you need is different from someone writing in Europe where truffles have been part of their culture and a seasonal produce for centuries (but even they get it confused as well.) In Australia where this is a relatively new agricultural crop the first inoculated tree plantings were in 1995 in Tasmania with the first truffles found three to four years later, but it was almost ten years before good commercial quantities were harvested.

If you need even shorter ‘grabs’ of fun stuff see our Truffles FAQ page.

What are truffles?

Truffles are in fact a mushroom that has decided to grow underground. They are a fungi but unlike the mushrooms that grow above ground and spread their spores on the wind to propagate, they have evolved to keep the spores inside a protective skin and depend on animals to dig them up and spread them around. To make that happen they need to have a strong scent that passes through the soil when they are ripe in winter, so that they are dug up, eaten and scattered in droppings (poo). Wild pigs and other forest animals love them.

That pungent smell and seductive taste is attractive to us humans too, so we hunt and dig them up as well. And we have done that for thousands of years.

Truffles have fallen in and out of favour over the centuries, even being banned by the Catholic Church who thought that because they tasted good they must be sinful and besides they were black (clearly evil) and no-one knew how they were formed (so must have been made by the devil). Pasta must have got boring without them so they were added back to the approved menu. There are references in the Bible and the Koran as truffles being food of the desert and we think they are almost certainly the ‘manna’ that kept biblical travellers alive.

There’s a good introduction to all that history in this downloadable PDF document here. Feel free to use it.

Spot the difference

The two most prized varieties of culinary truffle are the large white Tuber magnatum – above left, which doesn’t grow in Australia, and resists attempts at commercial growing both in Australia and in Europe. It is only found in a belt defined as ‘Meditteranean’ in the wild but shows signs of some expanding its area of growth – or we’re just looking harder. The other (above right) is the black winter truffle Tuber melanosporum . There are other varieties that grow wild in Europe and North America but more of that below.

You wouldn’t confuse them if you saw them but we often see prices for the European white truffle mistakenly used to value our local black (and the little white varieties). $5-6000 a kilo was the imported price restaurants paid for the large white Tuber magnatum over the last two seasons. In Australia, black truffle reached a top price of $2000 a kilo, slightly more when sold direct to retail in small quantities.

You can see they do look different but when a journalist/editor (or restaurant advertising agency) heads for a stock shot from the image library to illustrate a local black truffle story or a menu item, they rarely have Australian images and we’ve seen some really embarrassing  mix-ups. Even when we point out the mistake and say that it is not what our truffle would look like!,  the blunders remain on publication websites to compound the problem for your research.

So you need to be careful with that quick web search. People who know about truffles just scoff, but  most of the reading public don’t know enough about them yet so they are looking at your story as authoritative.

We do have some stock library images you can use, or at least to check your other sources against. Just ask. If you have worked with a photographer to produce a story, and a grower has explained all this to you, you’ll be ok. Just check the art director/sub-editor’s captions.

That very phallic object is a truffle being born C1600

Since no-one could see or understand how truffles grew and the earth was ‘scorched’ around tree roots that they were found near, the theory developed that they were formed by lightning. Summer thunderstorms were long considered essential to growing them but it seems that this was more climatic than an ‘electric magic’.  Truffles like a Mediterranean climate. Warm to hot summers, lots of summer rain and then cold winters.

Take away any of those factors, (and the high pH limestone soils they need to fruit) and they just stop or won’t grow. Which is what is happening in Europe where wild harvested truffles have been declining in quantity for twenty years. Climate change, environment change – as forests are no longer harvested and thinned and canopies close up, stopping the sunlight reaching and warming the soil, are all factors. This prompted experiments to dig up and plant-out small seedling trees that they hoped the truffle growing on the roots. Eventually the process of using spores and inoculating the soil and roots of (mostly) oak and hazel nut seedlings was perfected, and now cultivated truffle has filled the demand from declining wild harvests.

Farmed truffle. Our seasonal advantage

While there are edible truffle varieties that grow almost all year round, the season for culinary quality black and white truffles is in Winter. In the EU there is even a prescribed ‘best-by’ season and a cut-off to protect buyers from early or late quality differences and to contain over-harvesting in the wild.

Because our winter growing season is during the northern hemisphere summer, our growers saw an opportunity to export to those markets without competition (or presenting our fresh truffle against the frozen or canned truffles they would normally use).  The unique advantage of exporting truffles is their high value per kg weight. They travel well by chilled airfreight, and Australian truffles can be on tables in Europe (or USA and Asia) in just days.

The Southern Hemisphere seasonal advantage also applies to South Africa and South America, who are planting as fast as they can and will be a challenge to our market advantage. Given the long(ish) lead time from planting to maturity, we have less than ten years to consolidate distribution and prove to the world that we have a premium product with consistent high quality standards.

It's all black and white (and a bit brownish)

It was the black winter truffle, Tuber melanosporum, also called the Perigord truffle or French black truffle that was the first to be successfully farmed. It happened first in France and then in Italy, Spain, New Zealand, and now Australia. It’s the most cultivated variety because of it’s mellow flavour, and compared to white truffle that is almost always served shaved raw over a dish, allows some flexibility because it retains flavour in cooking. It also has a stable market value in Europe for processing into pressure cooked truffle juice and pastes. The fresh price paid there, like here, changes with seasonal availability and demand. The Australian growers are producing more than we can consume locally in our winter and are aggressively chasing export markets in Europe, America and Asia. The quality of our produce is highly regarded overseas.

Below are some 3D examples of what the varieties look like.

Fresh, frozen, dried or canned?

Fresh if you can get them. Always. Even chilled and sealed wrapped in paper in a jar, their flavour will decline after ten days or so, and lose weight from drying out. If quick frozen, black truffles can keep well under refrigeration with an inevitable decline in flavour ( you just need to use a bit more). As they go soft and squishy when defrosted, they are usually used while frozen and chopped or grated. Recent seasons in Australia haven’t produced a surplus that can be frozen and it has been hard to get them. Some restaurants freeze their own to extend their truffle menu.

You will see some dried product, pressure packed often with risotto rice, but as the natural aroma is driven off with heat it is more for appearance. In Europe canned truffle pieces and especially the juice are a staple restaurant item. Some chefs prefer the ‘pressure cooked’ taste and it is a stable year-round, food safe option when fresh truffle is not available. We haven’t started to can truffles yet in Australia.

If it is a cold autumn, the black truffle season in Australia can start in late May. They get blacker and more pungent in June but are almost always finished by September. One week you can get them and the next they’ve all gone. Gasp!

It’s seems a bit silly to call this truffle Perigord or French in a country where the consumers don’t know or care that much about identifying it as from France, and it is now cultivated in so many other places. There’s some agitation to just drop that and call our truffles Australian black truffles and fall back to the genus name Tuber melanosporum vitt when entering it on the export documents.  You pronounce melanosporum just as you’d expect,  mellah-no-spore-um. Sounds delicious doesn’t it?

Black truffle – Tuber melanosporum

Slightly less favoured for culinary use are Summer truffles Tuber aestivum. It sells for less but is available when the black isn’t. In Europe when it is ripe in late autumn, it’s know as Tuber uncinatum or Burgundy truffle. Then it develops a stronger flavour and is well regarded.

You pronounce aestivum, as  es-STEVE-um and uncinatum  OON-see-nah-tum.  Or UN-see-nah-tum.

Both of the these varieties are the same species. You will start to see these increasingly on the market but it still has to find its own value, usually much less than the black truffle. They are growing in some older truffiéres as an unwanted contaminant before growers had access to DNA testing of their seedlings.

Summer truffle – Tuber aestivum

Bianchetto – the ‘lesser white’ truffle  Tuber Borchii, has many small plantings but is still to produce commercial quantities. Its commercial value is lower than the large white Magnatum truffle and its aroma is initially more delicate and pleasant, but over time becomes stronger and more garlicky. The harvest period in Australia is after the black truffle season finishes gives it its own space in the market, but one that will require another education process as Australian chef’s and consumers learn to use them.

The name Bianchetto is pronounced BEE-AN-Ketto.  Borchii is pronounced Borky and it is traditionally inoculated on Stone Pine trees. That means if you can beat the cockatoos to them, they will produce high value pine nuts as an extra income for the growers.

Bianchetto – Tuber borchii cut face

The Australian truffle 'industry'

The green areas on this map, overlaid on the Bureau of Meteorology temperature averages for Autumn, are where we believe truffles could grow, given the right planting aspect, soil, water and seasonal variations. Some areas would struggle to produce ripe black truffle but could be ideal locations for Summer truffle or Bianchetto.

Say truffière please!

That’s the French name for a place where truffles are grown. It is pronounced TRUE-fee-air. If you can’t find the grave è in Word or the sub-editor scoffs at talking French, it is ok to write it ‘truffiere’ or call it a truffle orchard, or truffle patch. But there’s no such word as ‘truffery’ or ‘trufferie’ in any dictionary.
The person who grows them, is in French, a truffier without an accented e, pronounced TRUE-fee-er but we call each other truffle growers.

We’d appreciate if you get that right. Thank you.

Facts and figures

Best estimates. Our role as the representative body for the Truffle Industry comes with some special responsibilities to represent small growers who aren’t members for various reasons. So we’ve had to use many different sources to assemble this data every year,

1999 – 1 kg
2000 – 2 kg
2001 – 10 kg
2002 – 20 kg
2003 – 30 kg
2004 – 40 kg
2005 – 50 kg
2006 – 100 kg
2007 – 200 kg
2008 – 1,000 kg
2009 – 1,500 kg
2010 – 3,000 kg
2011 – 4,500 kg
2012 – 5,000 kg
2013 – 6,000 kg
2014 – 8,000 kg
2015 – 10,000 kg
2016 – 13,000 kg

In 2020 we estimate we’ll be producing 20,000 kg in Australia

We're going on a truffle hunt

Even if you can’t get a chance before your deadline, do it sometime anyway, and take your children. This is the best way to learn about how truffles grow, how hard it is to find them, what they smell like (and the soil around them). Many growers use the truffle hunts as an extra income stream and enjoy sharing their knowledge and demonstrating their dog handling skills. They often have a small truffle tasting, and since it’s cold, soup with truffle is popular or bread and truffled brie cheese. Look for growers that keep you in a small group so you can ask questions, get down and smell, and some even let you help dig out a truffle. Usually they have enough that they can sell you a truffle or truffle pieces, or even truffle products such as truffle infused eggs to take home.

More information please?

Ok, we’ll try. We are an organisation run by volunteers and it sometimes takes us time to answer you. If we’ve really left something out of this and our website, our media communications person is paid (not much) to respond but he/she will try to avoid tyre-kickers and non-media people that want to grow truffles in tubs, greenhouses, under the oak trees in your street, in tropical climates or help you identify the ‘truffles’ you found in the garden/bush/paddock. ‘It’s absolutely a white truffle (the cook at the servo take-away said it was)’.

Just use our contact page form (to avoid the spam).And if you have suggestions about how this could be clearer or more helpful, we’d appreciate your feedback.

Prepared by the Communications team,
for Australian Truffle Growers Association

Scroll down for More Technical stuff ( if you need it)

The taste test and synthetic ‘truffle oil’

You’ll most likely meet our fresh black truffles when dining so what do they taste like? Well, they retain some of their earthy origins. When freshly dug up some people smell that element like in beetroot. There’s certainly mushroom overtones but truffles are unique. Sex and old socks was the classic description which we guess is a mix of pheremones that make female pigs attracted to them (and easy to train finding them) and the sweaty socks which is that earthiness. It doesn’t help much because you can’t compare it to just one thing. Some truffles have a kerosene nose that chefs like, others hate. Sexy? Yes and they were even considered an aphrodisiac.

We can define exactly what the mix of chemicals is that give them their odour and one of them can be manufactured synthetically, a thioether called (2,4-dithiapentane). Manufactured cheaply in bulk it is then added to an oil, like grape seed or mild olive oil and sold as ‘genuine’ truffle oil at an exorbitant mark-up. Sometimes they throw in a bit of sterilised truffle so the label can claim it contains ‘genuine black or white truffle’. If the label says ‘contains aroma’ you know it has the chemical in it. While it is a strong flavour when used in cooking, it has nothing to do with the multi-layered complexity that a real truffle brings to a dish. Some people are even allergic to it.

And it doesn’t have the major attraction of all the truffles in containing glutamates, the natural flavour enhancers that appear in garlic, tomatoes, Parmesan cheese, potatoes and mushrooms.

Truffle has a natural affinity with fats, so milk, butter, cream and eggs carry it’s flavours and odours  (which is a big part of what we call taste). If it is used shaved in slices or grated over a warm dish such as pasta or risotto, the heat releases that unique smell and prepares you for eating it. White truffle is considered so refined that the idea of cooking it and driving off the scent means it is almost always shaved at the table, or made into a fresh paste.

Black truffle is a little more robust and can be blended with foie gras and cream to make the classic Perigord Sauce, it can be inserted under the skin of chicken before baking in a dish called ‘widow’s chicken’. But just shaving or grating on top of dishes as diverse as pizza and salad also see it shine.

How much should you use? Unfortunately lots of people go away from a first truffle meal with a ho-um feeling. The restaurant has to use enough so that you know you’ve enjoyed truffle while keeping an eye on their budget. We think an entree should have about 5 grams per serve (at $2 a gram that’s adding $10 to the dish without markup) and up to 10 grams for a large main course. Dishes such as truffled ice-cream need to use as much as the mixture requires but as it is usually (stored with) infused  into the eggs or cream for a few days before, they have their flavour and truffle to shave as well.

Once you get the taste, it is a seasonal addiction and you bemoan that you didn’t have one more truffle dish before they were gone.

The biggest difference between farming truffles in the the Mediterranean truffle regions and here in Australia is the soil. In Europe the soils are often built on a limestone base and weathering has meant that the pH of the soil is highly alkaline. ( pH is the measurement of whether something is acid or alkaline, eg. lemon juice has a pH of  2.0, milk sits about 6.6, pure water is 7.0, and baking soda is 8.30). The structure is usually coarser without a lot of clay. Sandy loam is ideal.

Australian soils are also very old geologically but over half our usable soil area is less than or equal to pH 5.5, which is below the optimal level to grow most crops as it makes most of the soil nutrients inaccessible to plant roots. So we have to raise the pH by adding lime before we can grow truffles. This needs to be done a year or two before planting out the inoculated seedlings and involves ripping the paddocks and spreading tons of lime. Then digging it in.

We think that our success in truffle growing has a lot to do with how adding that lime to the soil kills off any existing or competing mycorrhizas, the fungal threads that spread through all soils. The problem is then to restore the soil to be friable and healthy and a place an earth worm can call home.

The small seedlings are planted out from their soil tubes like most tree seedlings, then the care is much the same as any other orchard as they grow. Weed control, watering and some pruning is needed to control their shape and low branches. While we are caring for the tree above ground, the roots are preparing for truffles.

Truffles need a host tree. Because they grow underground they do not have access to sunlight to photo-synthesise sugars. So they grow in association with fine tree roots that they can draw sugars from and their even finer roots can share some of the mineral nutrients that the tree wants. Or at least that’s what seems to happen and we’d accepted as the process. We now think that the truffle isn’t playing as nicely and is perhaps more parasitic and controlling the exchange. The experiments are ongoing. We know that the truffles don’t want anything on the surface such as grasses that will compete for the transfer of moisture, so they create what is called a brulée, a dead patch of grass around the trunk, ( ‘burnt’ as in your Crème brûlée). It’s a welcome sign to a grower that there are truffles underground but it doesn’t guarantee you’ll find them. That seems to require a complex interaction of mating types in the truffle nodules on the roots and the ‘mycelium‘ in the soil, and now that we have ways to measure that and the DNA of the truffle varieties, it is becoming a much more scientific approach to truffle farming. Watch this space.

There are many tree varieties that can host truffles in their roots. The main choices in Australia are hazelnuts and oaks of two different varieties. There is an evergreen oak called the Holly or Holm oak Quercus ilex, and the deciduous English Oak Quercus robur.  They have been historically used for propagation here because they were available, often in the local churchyard or as street trees. You will sometimes see these mixed with Hazelnuts Corylus avellana which also lose their leaves in winter.