Thursday, 27 November 2014

Little Battlers

The smallest bat species here, such as Pipistrelle Pipistrellus spp and Lesser Horseshoe Rhinolophus hipposideros, weigh between 5 and 8 grams during the summer. They only need to put on a couple of grams of fat and they are ready for hibernation! By this time of the year they are tucked away in their hibernation site (although warm dry nights may still tempt them out). Lesser Horseshoes stay in hibernation from October to April, much longer than Pipistrelles, who don't get serious about hibernating until November and emerge as early as February if the weather is good. Their tiny size is why it is so important not to disturb them while hibernating. A single awakening could lose them enough energy that they don't make it to spring.

A downed Pipistrelle in our garage, not taking the hint to move into the nice safe toilet roll tube I am offering it. I'm wearing gloves because it is potentially not safe to handle bats with bare hands as they can carry serious diseases which can affect humans.
Bats have a dilemma though as they work to bulk up for the big sleep. They can't afford to get too fat or they risk being too heavy to fly. Both Pipistrelles and Horseshoes are exclusively insectivores. During summer they catch and consume as many as 3000 insects a night (I saw a calculation that worked out that this is the equivalent of a human eating 50 pizzas in a night), but during hibernation they wake only occasionally, if at all, to eat or drink. There are fewer insects around, so they conserve energy by hibernating. It's a delicate balancing act, putting on just enough weight to get through the winter. This is one of the reasons bats often roost socially -- they help keep each other warm. Roosting sites, which are used during the summer, can be tree hollows, rock crevices and all sorts of nooks and crannies in buildings (behind shutters and render which has partially detached from the wall are favourite places for Pipistrelles especially).

A hibernating Lesser Horseshoe in an old underground limestone quarry. 
Horseshoes are easy to recognise because of their habit of wrapping themselves up in their wings.
The hibernation sites here (as opposed to summer roosts) are generally abandoned limestone quarries, known as caves. They have stable low temperatures and constant relative humidity. In such places bats can safely enter a state of torpor where they lower their body temperature, slow their breathing and reduce their metabolic rate. By the time they emerge in the spring they will have lost half their body weight.

A small brown bat which I think is a Pipistrelle, but could be something else.
These little bats are about the size of a teabag, with a wingspan of about 20 cm. They live on average about 5 years but can live to 15 or so. The locals are quite tolerant of them, often recognising the sterling service they provide in terms of eating mosquitoes and midges. All bats are protected species in France. Nevertheless life is fairly tough for them here. Modern agriculture and its intensive use of insecticides is reducing their larder, and the many domestic and feral cats make their life a misery if they choose to roost in buildings or hunt near human habitation. Fewer and fewer roosting spaces are available in buildings as people renovate and fill gaps, block holes and renew blown render. Common treatments for woodworm in rafters and beams can have the unintended side effect of also poisoning roosting bats, even years after the treatment was administered. Bats like to follow linear features when hunting, and the loss of hedgerows in the countryside as fields get amalgamated to facilitate larger and larger machinery has affected the hunting success of the Lesser Horseshoe bats in particular.

A Pipistrelle flying over our garden.
A la cuisine hier: Nutcracking. Honestly, this is the most tedious task in the kitchen that I can think of, with the exception of peeling chestnuts. Walnuts are alright -- they are large and I never have a huge crop of them as our trees are still young. Hazelnuts on the other hand are always abundant, and about one shell in three is empty, even after culling all those with weevil holes and those that don't come away from their husks cleanly, as these are always empty. Their small size means they don't work with many commercial nutcrackers and you risk getting your fingers pinched. This year I resorted to holding the base of the nut steady in some pliers and whacking them smartly on the tip with the meat mallet. Still took hours and some nuts were still fiddly.

Wednesday, 26 November 2014

Fungi in the Orchard

Recently the Association de Botanique et de Mycologie de Sainte Maure de Touraine held its annual fungi exhibition. I went along to help set it up and I took the opportunity to get the fungi from our orchard expertly identified by my friend Jean Bouton. So this is what it turns out we have:

Warted Amanita Amanita strobiliformis (Fr. Amanite solitaire).
This one caused Jean to exclaim with delight, partly because it was a perfect specimen, partly because the species is rare. It is found in forests, oak woods, hornbeam woods on calcareous soil. It is a large white mushroom with flakes on the cap like many Amanita spp have (the most famous is the Fly Agaric).  The stem is thick and bulbous. Jean assures me it is very tasty and perfectly edible. However, further reading suggests that not only does it share the Fly Agaric's flaky top, it possibly contains the same hallucinogenic chemicals. Therefore, despite Jean's enthusiasm, I will not be eating it.

Ivory Funnel Clitocybe dealbata (Fr. Clitocybe blanchi).
This species is widespread and common, appearing in lawns, meadows and pelouses (short calcareous grassland). It is a small white mushroom that forms fairy rings. It is very toxic, potentially deadly and its nickname is the sweating mushroom because of the symptoms that very quickly develop (within half an hour) if it is ingested. The specific antidote to the poison muscarine that the mushroom contains is atropine -- so that's OK then -- if I accidently poison myself I'll just take a swig of Simon's eye drops that give him funny dreams or chew on the nearest Thornapple Datura stromonium, which is a terrible weed here.

Weeping Bolete Suillus granulatus (Fr. Bolete granulé).
This mushroom grows in association with pines and is edible with the proviso that you are best to wipe off the slimy coating on the cap, as it has a laxative effect. The pores will produce milky droplets when fresh and removing the pores before cooking is also recommended.  Neither the pores nor the flesh stains when damaged or cut. It is the most common of the Suillus species that grow in a symbiotic relationship with pine trees and can be included in commercially available wild mushroom products. Apparently handling it can make some people come out in a rash.

Tuesday, 25 November 2014

Catching the Train to the Chateau d'Azay le Rideau

The station at Tours has a series of 18 painted ceramic panels decorating the walls. Their purpose is to beautify the station concourse and entice travellers to the destinations portrayed. At present the panels are badly in need of conservation and a crowd-funding campaign is underway to raise the money to save them. Each panel will cost €8000 to clean, conserve and reattach the tiles to the walls. You can see a small test patch on this panel where conservators have cleaned to see what the effect will be. To learn more about the restoration fund and the panels themselves go to Ulule Gare Tours (in French).

We thought that it might be fun to show one of the panels every now and then, with the timetable information for how one gets there from Tours today. Azay le Rideau is a simple half hour journey from Tours. The station is on the outskirts of this attractive village, and it is a walk of 2 km to the centre of the village to get to the lovely chateau from the station.
Update: The City of Tours announced today that it would fund the restoration of a panel and has chosen this one.

Monday, 24 November 2014

Coriander Induced Musings

Parmesan cheese smells of vomit. It actually does, and especially the ready-grated stuff. That's because the two things share some volatile chemicals that create aroma. However, even though smell and taste are inextricably linked, the human brain, a master of cognitive dissonance, is perfectly happy to focus on the delicious savoury umami taste and very few people dislike parmesan cheese. The British like it so much that the Italians can't believe how much they use -- more is consumed in Britain than in Italy. It's not the only cheese that has a pungent pong either, as anyone who has taken a Pont l'Eveque home in their suitcase after their holiday in Normandy will know (ahem...). Quite a few highly prized cheeses share volatiles with stinky feet. Whether you eat and enjoy them or not is a matter of exposure to them ie whether you are used to them or not.

About a fifth of people of northern European origin utterly loathe coriander leaf (known to you by its Spanish name cilantro if you are from the US). I remember being told years ago that the Vietnamese word for coriander was the same as their word for stink bug. I've been unable to verify that, but I have discovered that the word coriander itself comes from an ancient Greek word for stinking bug and that the ancient Greeks were very familiar with the herb (and, undoubtedly, stinking bugs...).

A Hawthorn Shield Bug Acanthosoma haemorrhoidale, an archetypal stink bug, ambling about in the Forest of Loches. 
Many smells come from a group of volatile organic chemicals called aldehydes. Many people, like me, will describe the smell of coriander as like that of stink bugs. It turns out that coriander shares an aldehyde called trans Decenal 2 with stink bugs. It's an aroma that occurs naturally in foods as diverse as milk, tea and caviar as well as coriander, carrots and pork, and has been synthesised or extracted for use in the food and cosmetics industries. It is described as a fatty orange rose aldehydic floral green and the taste is fatty fried citrus.

Some people who think coriander smells like stink bugs loathe the stuff. Others, like me, love it. The difference is how our smell receptors respond to certain aldehydes. For some people, some stinky aldehydes seem to overwhelm everything else. Simon appears to be one of these people. For him, lavender smells of  stale sweat, not a mix of lovely astringent herbal scents. Likewise he hates rosemary, sage, cloves, cinnamon, saffron and nutmeg. Neither of us are keen on mint of any sort.

Simon is one of a small group of people who say that coriander tastes metallic. He has the same reaction to parsley. This group of people seem to be very sensitive to bitter tastes. Simon will taste the bitter elements in many green vegetables that I don't even notice, or perhaps enjoy. I like a good combination of bitter and sweet, such as good honey has or intense dark chocolate. Endive doesn't have much to recommend it though, it has to be said.

A packet of coriander from the supermarket. 
Auchan in Chatellerault is one of the few places apart from the specialist Asian supermarket Paris Store in Tours Nord that  I can usually rely on getting coriander around here. Sometimes they even have big bunches.
The French for stink bug is punaise (='stinker'). A French person will often tell you that punaises smell like stale almonds. Frankly, I don't know what stale almonds smell like, but presumably that cyanidey odour that too much almond essence gives you.

These sorts of very intense differences in perception of  taste and smell appear to be genetic, involving two genes linked to bitter taste and one to pungent flavours. Nearly half of Europeans have two copies of one of these genes, some have none. A significant number of these people report that coriander tastes soapy. Describing coriander as tasting soapy seems to be the 21st century version of describing them as smelling of stink bugs. I guess fewer people are exposed to stink bugs these days. As usual though, genetics isn't the whole story. Cultural background makes a huge difference, and for coriander lovers or haters this is possibly more significant. If you come from an Hispanic, Near Eastern or South-east Asian background you are much more likely than not to love coriander despite any genetic indicators. Like the cheeses, it's a matter of exposure.