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Could home fermenting catch on? Could home fermenting catch on?
(1 day later)
In this homogenous age of refrigeration, pasteurisation and conservative best-before dates, the slimy, gassy, murky process of fermentation is as alien to most western kitchens as the slaughter of animals. So far removed from the processing of our foods are we that the notion of ingredients crawling with microorganisms which, left in the right conditions, can deliciously preserve foods, seems either too good to be true or just plain minging. All this makes fermentation fertile ground for experimentation by avant-garde chefs such as Rene Redzepi. And so a process that may have seemed cutting edge in 3000 BC to the Sumerians is edgy all over again.In this homogenous age of refrigeration, pasteurisation and conservative best-before dates, the slimy, gassy, murky process of fermentation is as alien to most western kitchens as the slaughter of animals. So far removed from the processing of our foods are we that the notion of ingredients crawling with microorganisms which, left in the right conditions, can deliciously preserve foods, seems either too good to be true or just plain minging. All this makes fermentation fertile ground for experimentation by avant-garde chefs such as Rene Redzepi. And so a process that may have seemed cutting edge in 3000 BC to the Sumerians is edgy all over again.
Wild timesWild times
Of course, loads of everyday foods and drinks are fermented, from alcoholic beverages to bread and cheese, via soy sauce and balsamic vinegar, but the excitement among food lovers is about wild fermentation. Most mass-produced versions are made by killing off all the yeast and bacteria that live on them, then introducing pure, specially chosen cultures that will produce consistent results. We have Louis Pasteur to thank for this. Not only did he invent pasteurisation but he also discovered yeast and how to isolate it. But is wild fermentation ultimately better?Of course, loads of everyday foods and drinks are fermented, from alcoholic beverages to bread and cheese, via soy sauce and balsamic vinegar, but the excitement among food lovers is about wild fermentation. Most mass-produced versions are made by killing off all the yeast and bacteria that live on them, then introducing pure, specially chosen cultures that will produce consistent results. We have Louis Pasteur to thank for this. Not only did he invent pasteurisation but he also discovered yeast and how to isolate it. But is wild fermentation ultimately better?
According to an influential Tennessee fermentation revivalist with mutton-chop facial hair, Sandor Katz, who calls himself Sandorkraut: "My general observation is that in every realm of fermentation – beers, wine, breads, cheeses, cured meats – the easiest and most consistent way is to use starter cultures that have been isolated and selected. But the most celebrated examples of them, the highest expressions of them, with the most complex flavours, come from wild organisms that are indigenous to the foods." Katz begins the UK leg of the promotional tour for his new book The Art of Fermentation this week. Take salami, he says. "In the USA, all the salamis are made by adding starter cultures," whereas in Spain that's unheard of and they're willing to deal with a little bit more variability for the rich, complex side."According to an influential Tennessee fermentation revivalist with mutton-chop facial hair, Sandor Katz, who calls himself Sandorkraut: "My general observation is that in every realm of fermentation – beers, wine, breads, cheeses, cured meats – the easiest and most consistent way is to use starter cultures that have been isolated and selected. But the most celebrated examples of them, the highest expressions of them, with the most complex flavours, come from wild organisms that are indigenous to the foods." Katz begins the UK leg of the promotional tour for his new book The Art of Fermentation this week. Take salami, he says. "In the USA, all the salamis are made by adding starter cultures," whereas in Spain that's unheard of and they're willing to deal with a little bit more variability for the rich, complex side."
What do the yeast and germs do?What do the yeast and germs do?
Katz isn't sure we really need to focus on the science behind fermentation too much – after all, people managed to do it very well for thousands of years before Pasteur put the process under his microscope in the 1850s. But if you're feeling inquisitive, here's the gist of it. Pasteur was asked by a man who made beetroot wine, to discover why some of his batches had failed to become alcoholic and tasted, instead, like sour milk. He worked out that the alcohol was a byproduct of enzymes in yeast from the environment converting the glucose in the beetroot into energy, without using oxygen. "Respiration without air," as he put it, is what biologists now call anaerobic respiration. Pasteur discovered that the bad batches of wine contained more bacteria than yeast (which is a single-celled fungus). Bacteria ferment foods, too, but they produce lactic acid. Different ingredients, conditions and types of yeast and bacteria produce various results and byprodcuts, including ethanol, lactic and acetic acids and carbon dioxide. Sourdough breadmaking, which naturally involves friendly bacteria and yeast fermentation, produces all of these: lactic acid gives it that satisfying twang, acetic acid helps it stay fresh and mould-free, carbon dioxide makes it rise and the booze evaporates. Katz isn't sure we really need to focus on the science behind fermentation too much – after all, people managed to do it very well for thousands of years before Pasteur put the process under his microscope in the 1850s. But if you're feeling inquisitive, here's the gist of it. Pasteur was asked by a man who made beetroot wine, to discover why some of his batches had failed to become alcoholic and tasted, instead, like sour milk. He worked out that the alcohol was a byproduct of enzymes in yeast from the environment converting the glucose in the beetroot into energy, without using oxygen. "Respiration without air," as he put it, is what biologists now call anaerobic respiration. Pasteur discovered that the bad batches of wine contained more bacteria than yeast (which is a single-celled fungus). Bacteria ferment foods, too, but they produce lactic acid. Different ingredients, conditions and types of yeast and bacteria produce various results and byproducts, including ethanol, lactic and acetic acids and carbon dioxide. Sourdough breadmaking, which naturally involves friendly bacteria and yeast fermentation, produces all of these: lactic acid gives it that satisfying twang, acetic acid helps it stay fresh and mould-free, carbon dioxide makes it rise and the booze evaporates.
FlavoursFlavours
When we think of fermented foods, sourness, acidity and astringency spring to mind, balanced with rich, pleasing, buttery tones. But crucially, one of the most universally craved tastes, umami (or savoury), is greatly enhanced in fermented foods. The process breaks down proteins to release the amino acids, such as glutamate – "the single best elicitor of umami taste in humans," says leading nutritional scientist Paul Breslin, of Rutgers University. Another weaker umami-tasting compound, aspartic acid, will also be released, usually along with "free ribonucleotides, which can be great enhancers of glutamate's umami taste." Bread is slightly savoury, and so is beer and cheese, possibly yoghurt, wine and fermented meats, plus many pickles – especially Korea's national food, Kimchi, says Breslin, "which is often supplemented with fermented animals in the form of shrimp sauce, fish sauce, oyster sauce, etc." However, umami levels will vary from product to product. Parmesan cheese has much higher glutamate levels than cheddar, and champagne trumps cabernet sauvignon wine for savouriness.When we think of fermented foods, sourness, acidity and astringency spring to mind, balanced with rich, pleasing, buttery tones. But crucially, one of the most universally craved tastes, umami (or savoury), is greatly enhanced in fermented foods. The process breaks down proteins to release the amino acids, such as glutamate – "the single best elicitor of umami taste in humans," says leading nutritional scientist Paul Breslin, of Rutgers University. Another weaker umami-tasting compound, aspartic acid, will also be released, usually along with "free ribonucleotides, which can be great enhancers of glutamate's umami taste." Bread is slightly savoury, and so is beer and cheese, possibly yoghurt, wine and fermented meats, plus many pickles – especially Korea's national food, Kimchi, says Breslin, "which is often supplemented with fermented animals in the form of shrimp sauce, fish sauce, oyster sauce, etc." However, umami levels will vary from product to product. Parmesan cheese has much higher glutamate levels than cheddar, and champagne trumps cabernet sauvignon wine for savouriness.
Chemical compounds called esters are also produced by fermentation. These are known to infuse ales with unlikely banana and pineapple notes, and when I sniff my home-made sourdough bread, I swear I can smell buttery orchards. The fun thing about baking with whatever yeast and bacteria happen to be floating around your kitchen is that it's exciting, in a geeky and greedy way, every time you make a loaf. Anything can happen.Chemical compounds called esters are also produced by fermentation. These are known to infuse ales with unlikely banana and pineapple notes, and when I sniff my home-made sourdough bread, I swear I can smell buttery orchards. The fun thing about baking with whatever yeast and bacteria happen to be floating around your kitchen is that it's exciting, in a geeky and greedy way, every time you make a loaf. Anything can happen.
Will home fermenting catch on in a big way? Have you tried it? What are the most delicious fermented foods?Will home fermenting catch on in a big way? Have you tried it? What are the most delicious fermented foods?
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