Sourness has many subtle faces as shown by these Asian condiments. Look for speciality vinegars in gourmet supermarkets or region-specific shops and malls such as Yue Hwa, Golden Mile Complex and Lucky Plaza.
Making vinegar:The traditional process starts with a source of sugars, such as fruit or plant sap juices, or cooked starch fermented with yeasts. The sugars are converted to alcohols by yeast microbes. Bacteria then turn the alcohols into acids.
Each step must be well controlled to regulate fermentation and avoid producing off-flavours. Small parameter variations produce a wide spectrum of results. Ageing finished vinegar adds aroma and flavour complexity. For example, long-aged Shanxi sorghum vinegar is famed for its depth. Japanese kuro-zu vinegar, made from unpolished rice, is aged outdoors in ceramic jars until molasses-dark and very mellow.
• Live vinegar: Unpasteurised and containing live bacteria, this can be used as a starter to make more vinegar. As they grow, the bacteria form a raft of cellulose called a "mother", as shown here. It can simply be strained out of home-brewed vinegar and transferred to a fresh vessel of alcohol to kick-start more fermentation. Sold at health-food stores.
• Cereal vinegars: Rice, wheat, barley, sorghum and millet are common vinegar foundations across China and Asia. Shown here is a sorghum and millet black vinegar, which has a savoury, almost smoky funkiness.
• Rice vinegars:Mild and versatile white rice vinegars range from colourless to pale yellow. Shown here are a pale Taiwanese rice vinegar and a slightly darker Japanese rice vinegar.
Vinegars brewed from brown rice have more layered tastes, with savoury notes from the rice bran and germ. Glutinous rice vinegar can be made from white or black grains, the latter providing darker colour and earthier aromas than the former.
• Chinkiang/Zhenjiang vinegar: An iconic Chinese condiment with a rounded flavour, malty, earthy notes and a refined tartness, it is used as a seasoning, garnish or dip. Brewed from glutinous rice, wheat bran and darkened with scorched rice, it can be aged for many months. Shown here is a three-year aged Chinkiang vinegar.
• Red vinegar: Unrelated to grape-derived Western red wine vinegar, this Chinese vinegar is made from rice and/or other cereals, obtaining its brick hue and light fragrance from red yeast rice. Typically used as a dip or garnish for seafood, noodles, dumplings and soup.
• Palm vinegar: Vinegar can be made from the sugary flower sap tapped from various palm species, such as coconut and nipa, and also from coconut water.
Often slightly cloudy and distinguished by sweet, lilting, even floral nuances. Good for dressings, dips, marinades, and ceviche-type dishes. Shown here is a Thai coconut vinegar.
• Cane vinegar: Made from sugarcane juice. Clean-tasting, good for pickling and marinades. Filipino stores sell various types. Shown here are pale sukang maasim cane vinegar (photo 8) and darker sukang Iloco (photo 9), which is made from reduced cane juice and has sherry- and cider-like notes.
• Flavoured vinegars: These may be steeped with salt, sugar, herbs and other ingredients during or after fermentation.
Sweetened spiced Chinese black vinegar, sold in supermarkets and Chinese stores, is used in dishes such as the stewed ginger pig trotters traditionally given to new mothers. Filipino stores sell cane and palm vinegars infused with chilli, garlic and other spices for dipping or marinating meats and seafood. Fruit-infused vinegars, which may or may not be also made from fruit, are popular. In Japan, Taiwan and Korea, they are used in beverages and cooking.
• Distilled vinegar: Fermented from distilled alcohol, this has a clean, uncomplicated sourness.
• Artificial vinegar: Usually labelled as such, this is a solution of acetic acid made by non-fermentative methods. One-dimensionally sharp, it is more suited for cleaning than eating.