Alcohol made from fermented grain (e.g. whiskey, beer) is not permitted on Passover. Alcohol made from other sources is permitted. Examples of permitted types of alcohol are grape wine and vodka made from potatoes.
If you were able to find corn vinegar that is certified kosher for Passover, it would be kitniyot which means that the majority of Ashkenazi Jews would not use it.
As capers come packed in brine, they require a kosher for Passover certification. However, because the brine used for capers has vinegar in it, it is not possible to find brands that are kosher for Passover. If you could find fresh capers, they can be eaten.
You can substitute regular balsamic vinegar for white balsamic vinegar in the recipe.
Yes. Balsamic Vinegar is vinegar made from grapes, as opposed to rice vinegar, or white wine vinegar. Balsamic Vinegrette is a salad dressing, specifically a mixture of Balsamic Vinegar, often with herbs, spices, and olive oil.
It would have to be certified kosher for Passover.
The label has to say "Kosher for Passover"
Yes, only if they are specifically certified kosher for passover. You can find kosher for Passover olives at any Jewish supermarket
When you purchase balsamic vinegar, you do not get the oil in the vinegar. However, it is possible to purchase a pine nut oil and balsamic vinegar salad dressing.
It can be, it would require a valid Passover hechsher.
no. You can not substitute any other vinegar for balsamic and get the same flavor.
I think "rendered balsamic vinegar" is the same as "reduced balsamic vinegar" - heat it up in a pan until it has evaporated to (at least) half the volume that it was originally.
Yes, it can be since it is made from wine, which can be Kosher for passover if created under appropriate supervision. The bottle would require a kosher for Passover hechsher.