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The Cook Up with Adam Liaw
It's a bit of a mystery, but that hominids (and humans in particular) developed a taste for the sweet-sour combination through the consumption of rotten fruit. The right balance of sweet and sour in the fruit indicated that it was full of beneficial yeasts and lactic bacteria that could increase the chances of survival. The wrong balance indicated the fruit was dominated by dangerous filamentous fungi.
'Sour' is really just a rough guide to a food's low pH or acidity level. It can also indicate that a food is high in vitamin C, a nutrient our ancestors stopped manufacturing approximately 60 to 70 million years back. So, eating sour foods can increase the acidity and vitamin C levels of the food we eat.
But sour isn't for everyone, which is where sweet comes over to play. It balances the tart sourness of food and is even fundamental in indicating that beneficial fermentation is taking place.
Enough with the science, because we all know that getting juuust the right balance of sweet and sour is an art form. Everyone tastes sour flavours differently, so to arrive at an appealing balance between the two you need to taste, taste and taste again.
Of course, it's helpful when a top recipe gives you a measured jumping-off point. To accurately hit your sourly sweet or sweetly sour spot, jump off from here.
Suwisa Phoonsang is a big believer in singing while cooking curries. Credit: Darcy Starr
Credit: Lottie Hedley, The Great Australian Baking Book
This sublime dahl comes from the western Indian state of Gujerat and uses tamarind and lime for sour and jaggery and tomato for sweet. These golden, orange-scented ricotta fritters served with honey-poached rhubarb and strawberries, are ready in just 25 minutes. The combination of sweet and sour flavours will leave everyone raving about this delightful treat. A splash of vodka helps release specific flavour compounds in the tomato paste that can only be unlocked by alcohol, creating a pasta sauce with a rich, complex taste. The balance of sweet and sour notes in the sauce adds a unique depth that you won’t want to miss. Tamarind broth with beef and water spinach Credit: Luke Nguyen's Food Trail
Filipinos are also inclined to bring tamarind's intense sour taste into the mix. In this pork sinigang, the fruit works beautifully with the sweetness of pork and tomatoes. If you’re short on time but still craving the classic duck à la orange, consider using duck breasts instead of roasting an entire duck. This simple substitution can drastically reduce your cooking time while still delivering the same rich, succulent flavours. Paired with a sticky-sweet orange sauce, this one is a winner! Sweet and sour sardines (Sicilian sarde a saor). Credit: Chris Chen
Let's not forget the work of guava as an agent of sour. This is one zesty fruit that demands a sweet friend, in this case, oodles of sugar and cream cheese wrapped up in pastry. Just in case you've come here for the classic, here she is. Every mum has a recipe and this one is Sam Young's. Express no surprise that there are added strawberries. Just consider them a sweet bonus... 
