The shelf life of Ultra Clear rice protein powder

Mast O Khiar, as you mention mainly consist of plain yogurt and cucumbers and most recipe do not require much more than that. Because of such, the shelf life for the yogurt product will be the shelf life of the yogurt itself. If it is a store bought yogurt, then the shelf life should be about 2 weeks in the refrigerator.

Make sure to store the sauce in an air-tight container. Most tubberware should work. Those soup containers from Chinese takeout orders work perfectly.

EDIT: After a bit of a debate in cooking chat, I decided to change my answer a little. The reason I said 2 week is because personally I had eaten 2 week old Mast O Khiar. However it could be recipe dependant so it could be different for a different recipe.

However it is very easy to tell whether yogurt OR cucumber is bad.

Mast O Khiar should have a very fresh/clean aroma. When yogurt turn bad, it releases a rancid smell. If it smells bad, dont eat it.

If you see fuzzy mold it's a good idea to throw it out.

There are three major things that will effect the "natural" shelf life of the compote, in that they could extend it considerably past the normal shelf life of the ingredients individually:

• How sweet is it? If it is sufficiently sugary, to the level of a jam or jelly, the sugar in the compote will act as a preservative.

  This is because any bacteria or mold that try to colonize the product will be dessicated, as water exits their cells into the sugar medium via osmosis.

  The problem here is that sugar is hydrophylic, and will easily attract water from the environment when the jar is opened, or when a wet spoon is put into it. If the surface becomes diluted with water, and thus the sugar is less concentrated, mold can get a foothold. So this kind of product is best stored in the refrigerator once opened.

• How acid is it? Very, very acidic foods are less hospitable to most pathogens.

• How salty is it? This one doesn't usually apply to compote recipes, but high enough salt levels also make foods inhospitable to most pathogens, again due to the dessication of their cells via osmotic pressure.

The specific recipe you linked to--at least the compote portion itself, excluding the vinegar syrup and the rest of the recipe--appears to have none of the characteristics that lead to a long shelf life. It should be held no longer than its most vulnerable ingredient, which would be the weak sugar syrup, so it is probably good for several days to a week in the refrigerator.

Now, in general, things named compotes tend to be far sweeter, and far more acidic than the recipe you have linked to.

In these cases, as ElindilTheTall points out, a very, very sweet recipe (jelly-like or jam-like sweetness) will last for many weeks in the refrigerator, and a couple of weeks at least at normal room temperature.

Finally, many compotes are amenable to home canning, if they are sufficiently acidic.

Canning has risks, especially for botulism, so you should only use recipes and methods from a very reputable source when doing canning, to ensure that the product is sufficiently acidic to be safe for the canning method used. Follow all of the techniques and prescriptions in the methods, as well, but I won't turn this into an essay on canning, which is not my area of expertise.

For those compotes that are properly canned, you should get an indefinite shelf life prior to opening, as long as the seal on the canning jar remains intact.