Dad’s cooking secret: Top left salt (soy) – top right, sweet (palm sugar), bottom left, Sour (lime), bottom right, hot (la-yu oil) –
Tom Kime’s cookbook, Exploring taste and flavour, demonstrates how the tastes of salt, sweet, sour and hot are so important in cooking.
We associate these four tastes most commonly in Oriental food. A Thai curry for example, will be flavoured with a balance of salty fish sauce, sweet palm sugar, sour lime and hot chillies. But Kime also suggests that the everyday BLT is a combination of these four essential flavours: bacon is salty; white bread is sweet; tomatoes are sour; and leaves such as rocket are hot and peppery.
We can imagine other foods working to the same principles. An American BBQ sauce is a taste sensation bigger than the sum of its parts, but those parts comprise salt, sweet, sour and hot.
Thinking about food through these four prisms of taste can open up new possibilities for seasoning and adding flavour to our food.
The four tastes can come in many forms – salt can come from cured meats, anchovies or hard and aged cheeses such as Parmesan, cooked onions are sweet, as are carrots, beetroot and other root vegetables, sour can come from citrus fruits but also vinegar, tamarind, yoghurt and creme fraiche and heat can come from pepper, but also chillies, ginger and mustard. So an apparently mild and nondescript cauliflower and cheese can be flavoured by a saute of sweet onions and a sauce of salty cheese and hot mustard, finished with a little creme fraiche or a squeeze of lemon – all four tastes again…
True, not all food is balanced in this way. Pairs of flavours can work well. ‘Sweet and sour’ come together famously in the classic Chinese sauce – but also when sweet pork is paired with sour apples. ‘Salt and sour’ are an effective duo as in ‘salt & vinegar’ flavoured crisps.
Surprisingly, food rarely comes in the form of a single flavour. Even a bag of sweets can be a complex melange of flavours – usually including fruity or sour flavours. Bite into an apple and it will seem a perfect mouthful of sweet flavour. But in fact the fruit is both sweet and sharp. We may crave sweetness, but we also need a little sour to offset the cloying effect of sugars.
It appears our palate is designed to always seek other taste dimensions. If we add a piece of cheese to our apple we are pleased with the extra taste of salt. So we also add a pinch of salt or salty nuts to an apple crumple (or add salt to caramel or chocolate). And there are many fruit recipes which push the numbers of flaovurs, such as grilled plums or strawberries doused with acidic balsamic vinegar and a grating of pepper.
Often the flavours are all present – but not in the same place. Chinese ‘salt and pepper’ prawns sound very happy with their two flavourings – but they are served with a ‘sweet and sour’ dipping sauce. In France they might serve a simple salad of sweet lettuce with a separate salty, sour and hot dressing. It is interesting to note that Mexican food is not ‘hot’ per se, dishes can be quite mild but are served with an assortment of hot salsas and relishes.
In Indian cuisine the flavours take on philosophical meanings and are considered essential to balancing the humours of the human metabolism. It is traditional therefore to provide meals with the flavours separated into different bowls or dishes, such as a spicy, salty curry, a sour yogurt dish, a hot and bitter pickle and a sweet chutney. It is also evident in fine dining kitchens that chefs will construct highly complex dishes with the flavours concentrated into individual elements. This is articulated in televised cookery competitions where the judges make their assessments: ‘The meat is well seasoned and is nicely balanced with the sweetness of the puree, acidity of the fruit and spiciness from the crisp vegetables…’
And it does not stop with these four tastes. We can add bitter to the equation. Salty peanuts are perfectly balanced by bitter beer. Even chocolate has subtle bitter notes. However, bitter is the odd one out, when it comes to taste and flavour our palates are naturally suspicious of bitter tastes – a primordial indicator of toxins.
Most chefs now assume that there is a fifth taste: umami. Why is tomato ketchup so compellingly good? Apart from the distinct notes of all four tastes, there is also a satisfying savouriness and unctuousness that comes from the tomatoes – that’s umami. Chefs keen to enhance their food will work with foods rich in umami such as tomatoes, mushrooms, cheese, soy and even seaweed.
So when it comes to tasting our food and seasoning – there’s a lot more we can do than reaching for the salt and pepper…