UK Truffle species for the gourmet table

There many hypogenous fungi, fungus that have no parts over the ground, and truffles. However few are sought as a gourmet ingredient. There are currently four different species of truffles which are hunted all over Europe, which are also found in the UK. Some truffles are best cooked, others raw, and are sought for by different industries. The canning industry for example is keen on black(ish) truffles that can stand the sterilisation process, or to sell them in pates for example. Restaurants and individuals may wish to use them in fresh dishes. Different species suit best specific recipes, following some key keeping, preparing and serving rules. The terminology in the UK regroups three of these under the same heading of Tuber aestivum. They actually grow differently, under different conditions, even if the season seems to overlap. Here are some pictures for comparisons when it is the most confusing.


Fig 1- Whole truffles-, T. uncinatum, T.mesentericum, T. aestivum (European terminology) ripe for the season in September


Fig 2 Same truffles cut through to expose the gléba (flesh)

TUBER AESTIVUM (T.a.): APRIL-SEPTEMBER

I have collected only a few specimen, some large and some extremely small. The black péridium (outer skin) seems to have a frantic activity, just like the growing ‘peaks’ of the Alps. There are scales growing it seems like from underneath continuously, pushing other sharp sides apart for another to erupt and take its place to form irregular warts. The warts are large, and high. I have found that even at maturity that there is little perfume attached to this truffle compared to others. The season is reported to be April to September, but left to ripen in August-September, I have found the flesh to be of a dark colour with the white veins much spaced out (gléba). There seems to be no reason to call it therefore white truffle, nor summer truffle in my mind, as there is no such attribute, unless it is unripe. One of several kilos was recorded.

TUBER UNCINATUM(T. u.): MID-AUGUST TO MID FEBRUARY

The first ‘ripe’ specimens are found in the UK from mid-August peeking through the soil, till 10th February. This would depend upon the weather. The early truffles of this species however do not reach the rich brown colour of Tuber uncinatum found deeper in the ground later on. The perfume can be as strong however. If the perfume is strong, and there is a grey-brown colour, they are best picked and used quickly. The truffle must however have a strong colour. Indeed, some have been found to have a decent perfume, but no colour and were definitely unripe, white, with no taste.
There is no reason to call this truffle either white, summer truffle, yet the press often refers to the UK truffle as white summer truffle or aestivum. This truffle species ripens in the autumn and winter. The warts will be nicely formed, and may differ in size from one side of the truffle to another. They can be flat, but ripe nice truffles seem to have raised more or less even warts. Some truffles are small and round(ish) with potentially a small depression from the size of a golf ball to a tennis ball, others seem to have a complex form, with different parts having reached different levels of maturity and can be much larger to 11cm in diameter (mostly quite ripe). The largest recorded was around 700g.
This is the best UK truffle, with a strong yet delicate mushroom nutty perfume and taste, and recognised as the queen of truffles, if the Tuber melanosporum is king. Much of it is lost if cooked higher that 60 degrees. If you are not used to such ingredients, eat it raw (left to transfer its perfume in the fridge), or add raw to a hot dish and cover for at least 5 mn before eating…!

TUBER MESENTERICUM(T.m.): MID-SEPTEMBER-TO FEBRUARY

Compared to the other two truffles, this is a smaller truffle. Those I found never reached the size of the tennis ball, and the first really ripe I found was in Mid-September, not August (France). They can have a kidney or pear shape initially, with a small depression to two depressions to fairly deep cavities, but ripe I found them almost round. When unripe, they have a strong ‘unpleasant’ smell of medicine cabinet. When ripe their perfume reaches the level of the melanosporum truffle in certain dishes. It requires skills and knowledge to slice through this truffle through the dip or the cavity to find the white veins parallel at the dip and near it as well as in its cooking. The cavity is a determinant (at the naked eye) of mesentericum species once ripe. The distinct perfume is often a more compelling determinant of the species.
Chose this truffle if you wish to use truffles in your roast as it can stand that sort of cooking, however do not forget to prepare your dish well in advance, so the flavour permeates throughout your meat before cooking.


Fig 3: Knobbly ripe Tuber brumale in comparison to a ripe T. uncinatum (gléba and péridium)

TUBER BRUMALE(T.b.): JANUARY-MARCH-

This truffle is not grouped with the others in the UK. It is very unlikely to be mixed with the others without being noticed. Like the mesentericum,Tuber brumale can stand high temperatures. It is easy to distinguish when young as the gléba (inside flesh) is pale grey (the other white), the péridium is almost smooth, with wide spacing whitish veins for a considerable time until ripe when it becomes dark grey. The truffle is knobbly, generally quite small but can reach just under tennis ball size.
The majority or T. brumale are quite small, when looking at a basket of freshly picked unsorted truffles rarely as large as a walnut. Their season is the same as for Tuber melanosporum, found in more southerly climates, and is often found mixed with them. The péridium (outer skin) has tiny warts when ripe, and they come off easily during the cleaning and picking process if ripe, unlike any of the others.
Come Christmas, this truffle is also useful for roasts. It favours a different type of soil, a much heavier soil such as clay. A large area of Anglia is covered in clay where these may be found wild. January is the start of the French season. I find it difficult to pick ripe ones due to the small size and the cover of sticky clay. Once disturbed, the truffle looses its food source and dies.