Rouxbe

I like to make big batches of mayonnaise in my food processor, and unlike every recipe I've seen which says you can only keep it a week, mine keeps for two months or more in the fridge. The secret? Add several tablespoons of active-culture whey while making it, then, after putting it into your storage container, leave the container out on the counter overnight, refrigerating it in the morning. This turns your mayonnaise from a potential petri dish for bad microorganisms into a filled ecology for good organisms. Since the ecological niche is already filled, bad organisms have a hard time getting in. This makes it not only more convenient, it is a very healthy addition. One thing, though...if you use this to make Waldorf salad, you'll notice the salad tastes slightly fermented on the second day, even if you keep it in the fridge. (Personally, I think that's a plus.)

You get active-culture whey by straining active-culture yogurt through cheese-cloth or other cloth. For mayonnaise, you'll only need several tablespoons, but whey is a great addition to other culturing projects like sauerkraut or kim-chee. It ensures that it works to perfection every time.

Another trick I use for mayonnaise is to use 4/5 olive oil and 1/5 coconut oil. The two flavors balance themselves so that neither is overpowering.

Well, yes and no. If you're using yoghurt to get your whey (second paragraph above), then it's Lactobacilli acidophilus, a beneficial bacteria. If you're using kefir, which is what I currently use, it would be a combination of several yeasts and bacteria.

As for how much...no need to be exact. I'd use a tablespoon of whey for a small recipe, maybe three tablespoons for a large one. All you're doing is innoculating it...that is, giving it a big batch of microorganisms to get it started.

You probably can't find active-culture yogurt at a regular grocery store, unless perhaps you live in California. Look for plain, unflavored yogurt at the health-food store. It should have some variation of the words "active culture" on it. To strain out the whey, I use a very clean men's cotton handkerchief to line a large seive, and then just pour in some yogurt and let it drain into a bowl for several hours. It should produce a thin, yellow liquid that is slightly sour...that's whey.

Culturing - another word is fermentation, also pickling - milk, vegetables, even meats, using beneficial bacteria or yeasts, is a very, very old art. Almost every traditional culture around the world cultures something. (Sorry for using two definitions of "culture" in the same sentance...) Pickles, sauerkraut, kim-chee, natto, miso, tempeh, yogurt, kefir, koumiss, kvass, kombucha, chutney...the list is endless. The only reason we don't know about it today is because our food chain has become big business, and culturing is inherantly small-batch. As a result, they replace fermentation over time with salt and vinegar, and call it "pickles" or "sauerkraut".

From the Wikipedia article on fermentation of food:

Food fermentation has been said to serve five main purposes:
1. Enrichment of the diet through development of a diversity of flavors, aromas, and textures in food substrates.
2. Preservation of substantial amounts of food through lactic acid, alcohol, acetic acid and alkaline fermentations.
3. Biological enrichment of food substrates with protein, essential amino acids, essential fatty acids, and vitamins.
4. Detoxification during food-fermentation processing.
5. A decrease in cooking times and fuel requirements.

Anyhoo, you can find lots and lots of info on the web about culturing. My favorite book is "Nourishing Traditions" by Sally Fallon and Mary Enig. It is a wonderful health treatise/cookbook, and has a great chapter on culturing.