What's the difference between taste and flavour? Now, there's a tale. It may sound a bit weird, but you taste with your tongue, but you register flavour with your olfactory bulb, up there behind the bridge of your nose. Don't believe me? Well, try this.
Get a piece of chocolate and some table salt. Squeeze your nostrils so you can't breathe through your nose, and put some chocolate in your mouth. Start chewing, still holding your nose; do not swallow. You won't taste anything. Now, with the chocolate still in your mouth and your nostrils still squeezed, take a pinch of salt and put this in your mouth. With your nose still sealed, you will be able to taste the salt, but not the chocolate. Now let go of your nose and the flavour of the chocolate will come through.
This experiment demonstrates how we taste. Tastes - sweet, sour, salt, bitter, and the mysterious fifth taste, umami - are registered on the tongue. As we eat and swallow, we save a little of the food right at the back of the tongue. This enables the opening to our throat to widen, allowing air to pass over the flavour molecules passing through our olfactory bulb and out of our nose. Our brain then connects the two systems together so that we assume that most of it is going on in our mouths.
But connecting these two systems is not the only thing to deal with. It has to pull in sight, sound and the most powerful of all, smell, as well as sort out cultural and social influences as well. The Japanese detest rice pudding, but think nothing of eating live soft shell crabs. And we happily eat prawns, but are shocked at the thought of eating grasshoppers.
It may seem equally strange to some to include what looks like a straightforward recipe for strawberries at this time of year, but there is method in my madness. Or I think there is.
A couple of years ago, Professor Andy Taylor at Nottingham University carried out some of the tests on the brain-to-palate connection. One of these involved strawberry juice. Fresh strawberries were juiced. Half of the juice was mixed with water and the other half with sugar. The consistency was adjusted so that they were both the same. Tasters were tested using a device that can detect what flavours exist in the olfactory bulb. They were fed both the unsweetened and sweetened juice. Although everyone tested said that the actual strawberry flavour was stronger in the sweetened juice, the strawberry flavour registered in the olfactory bulb was exactly the same.
The same test was carried out in the Far East and, with a couple of exceptions, there was no detectable difference. They then repeated the test with an additional juice mix, this time with monosodium glutamate (MSG), the flavour-enhancing salt used extensively in Far Eastern cookery.
Europeans still perceived the sweetened juice as having the strongest strawberry flavour, however, while those tested in the Far East believed the MSG mix to possess the most perceptible strawberry character. Although the actual flavour of the strawberries was the same in each test, we Europeans, having a sugar-based diet, found that adding sugar made the fruit flavour more pronounced. To people with a salt-based diet, it made no difference, but adding MSG did.
A couple of months ago, I received a letter from a reader advising me to provide seasonal recipes. I've got nothing against using raw materials in season. In fact, I'm all for it. Food usually tastes better in season. But the point of these articles is to lay down a few ground rules for a new kind of cooking. Perhaps my correspondent will forgive me for suggesting this particular strawberry recipe. Keep it until the strawberry season gets under way.
This recipe serves six.
Strawberry juice not only makes a fab soup but is also great for making drinks, pouring over ice cream, or adding to rice pudding. And it keeps well. But if you can't be bothered to make it, you can heighten the flavour of strawberries simply by sprinkling unrefined caster sugar over them half an hour before serving. When preparing strawberries, hull them (that is, remove the core) just before you macerate or use them. Don't wash them before hulling, as they will absorb water, destroying their taste and texture. If you're doing the whole recipe, you'll need to begin the day before. You'll also need some muslin.
For the strawberry juice
1 tbsp icing sugar
1 tbsp water
Hull and quarter the strawberries, put them in a metal bowl and sprinkle them with the sugar and water. Set this bowl over a saucepan of simmering water, cover with cling-film and simmer very gently for 90 minutes.Then put the contents of the bowl into the muslin, tie it up and hang it overnight, set over a bowl to catch all of the juices. For the soup
125ml fruity red wine
1 tbsp unrefined caster sugar
The above quantity of strawberry juice
Extra virgin olive oil
Orange flower water, to taste
Hull and quarter the strawberries, put them in a bowl, add the sugar and pour over the strawberry juice; leave this mix to macerate for two hours. Zest the orange and lemon, taking care to remove all of the white pith. Juice the fruits and reserve.
Meanwhile, bring the wine to the boil, flame it to reduce some of its acidity, then add the zest and juice of the orange and lemon. Now reduce the wine by half. Strain this liquid and set aside to cool. In a liquidiser, combine the macerated strawberries with the red wine reduction and blend. Add the strawberry juice.
You will now need to finish this by using your taste buds. Add the orange flower water, about one-tablespoon to begin with. You may need to add a little more sugar and orange juice. The important thing here is to keep on tasting to get the right balance. Give the soup a really good blend and finish off by adding the black pepper to taste.
You now have a few options: you can hang the soup again overnight. This will produce a wonderfully concentrated essence of strawberry; you can pass the soup through a fine-mesh sieve; or you can serve it as it is, adding extra strawberries for texture if you want.
To serve, dribble over a little best quality virgin olive oil. Finally, if you are feeling adventurous, finish the dish by sprinkling over some freshly picked rose petals!
Heston Blumenthal is chef/proprietor of The Fat Duck, Bray, Berkshire.