Q A few years ago, armed with an Indian cookbook I received as a present, I set out to make some delicious Indian dishes.
This went well, mostly, until I hit some recipes calling for mustard oil.
I purchased a bottle of the amber-coloured oil under the brand name Suraj. All the ingredients were prepared and I started with a teaspoon of mustard oil in the pan.
Suddenly, I noticed the label said: "for external use only." I discarded the oil and continued to make the dish without this oil.
I emailed the food company and asked at the supermarket what this warning label meant, but have yet to receive a satisfactory answer.
I wonder if you have any ideas on this mysterious oil, sold as a food, but labelled to be used only externally?
R. Stanley, Maple Bay
AAccording to the website of Indiabased Sunrise Foods Limited, sunrise.in, mustard oil is made from mustard seeds. The company says that its production volume, world-wide, is third, after soy oil and palm oil.
Mustard oil has a pungent flavour and aroma and in Asia -specifically in India, Pakistan and Bangladesh -it is used for medicinal and culinary purposes.
In the kitchen, mustard oil is used for frying, as a flavouring and, because of its preservative qualities, in preserves such as chutneys and pickles.
When cooking with it, to temper its pungency, a number of sources said you should heat mustard oil to the smoking point and then cool it to the required temperature.
Sunrise Foods says the oil contains the fatty acids, oleic acid, linoleic acid and erucic acid. It is the erucic acid that has government authorities in Canada, the U.S. and the E.U. warning people not to consume this oil.
According to the U.S. Food and Drug Administration website, fda.gov, expressed mustard oil is not permitted for use as a vegetable oil.
Mustard oil may contain 20 to 40 per cent erucic acid, which the FDA says has been shown to cause nutritional deficiencies and cardiac lesions in test animals.
According to the book, On Food & Cooking: The Science & Lore of the Kitchen, mustard oil also contains irritating isothiocyanates, a natural chemical compound.
That explains why mustard oil sold in the western world would have the words "for external use only" on the label. Good to use for a massage, but not for panfrying fish.
However, no studies on humans have been done and conflicting information can be found saying that the oil is actually heart-healthy because of those fatty acids.
Also, as noted above, the oil, which adds a distinctive taste, has been used for centuries in other parts of the world and that won't likely change in the foreseeable future.
Q Would you be able to do an overview on the shelf life and storage of oils and vinegars?
If you're unable to find a particular type of vinegar requested in a recipe, for example, blackberry vinegar, is there a way to create vinegar that would have a similar flavour?
Audrey Noel, Victoria
ABecause there's quite a bit of information on these subjects, I'm going to answer the vinegar part of Audrey's question today, and answer her query about storing oil next Sunday.
According to the New Food Lover's Companion, the word vinegar is derived from the French "vin aigre," which means "sour wine."
The book says vinegar is made by bacterial activity that converts fermented liquids, such as wine, beer or cider, into a weak solution of acetic acid, the component that makes vinegar sour.
That acid also works as a preservative, which is why vinegar is used in such things as pickles.
The book says vinegar should be stored in a cool, dark place.
Unopened, it will keep indefinitely; once opened, it can be stored for about six months.
If you store some vinegar for a very long time, or improperly, it can become cloudy. This cloudiness is referred to as "mother of vinegar." This is because vinegar at this stage can be used as the base to make more vinegar.
If that vinegar has an "off" smell, you should discard it. If it does not, you can make it clear again by straining it through a paper coffee filter or fine sieve lined with cheesecloth.
If you can't find a particular type of vinegar, such as a berry-flavoured one, you can make a version of it at home by using inexpensive, widely available cider vinegar and fresh fruit. Here's how to do it.
BERRY VINEGAR
When testing this recipe, I used imported berries with good results. However, to create the finest tasting vinegar, it's best to make it in the summer, when local berries are picked when ripe and full of flavour.
Cooking time: A few minutes
Makes: About 1 1/2 cups
1/2 lb. whole blueberries, raspberries or blackberries, or a mix of berries
1 1/2 cups apple cider vinegar
2 Tbsp granulated sugar
Place your berry of choice in a medium, stainless steel or heatproof glass bowl.
Place the vinegar and sugar in a non-reactive (not aluminum) pot, bring to a boil and then pour over the berries.
Cool to room temperature, cover and allow the berries to steep in the vinegar at room temperature for two days.
Set a sieve over a bowl. Line the sieve with cheesecloth. Strain the berry-vinegar mixture through the sieve. Gently push on the berries to release any liquid in them.
Transfer to a sterilized glass bottle or jar with a tight-fitting lid.
Label, date and store the vinegar in a dark, cool place for up to six months.
Eric Akis is the author of the recently published Everyone Can Cook Slow Cooker Meals. His columns appear in the Life section Wednesday and Sunday.
eakis@timescolonist.com
If there is a cooking issue that has you scratching your head, send your question to Eric by email at eakis@timescolonist.com, by fax to Ask Eric at 250-380-5353 or by regular mail to Ask Eric, Times Colonist, 2621 Douglas St., Victoria, B.C., V8T 4M2.
