Ytdyklly

I don't tend to keep any white wine in the house for cooking and have a bottle of rice wine vinegar to use up - only used it once and don't know what else to use it for.

Could I use rice wine vinegar at the start of cooking a risotto?

I would not use any vinegar. You will not want the sour taste that vinegar will leave. You will have a better final result if you just omit the wine. If you feel like it needs a little acidity at the end add a light squeeze of lemon (or even a couple of drops of vinegar). However, I've made risotto plenty of times without wine or extra acid...no problem!

Yes, you can, although I'd suggest adding a little sugar to it to offset the sharpness of the vinegar. About 1 tsp in 3/4 cup of vinegar should do it. However, if your rice vinegar is "seasoned rice vinegar", then it already has sugar in it (and salt). Add no sugar, and decrease any salt you'd normally add by 1/2 tsp.

Other substitutes that work for the wine in risotto are lemon juice (decrease quantity, add sugar), sherry (straight up), wine vinegar (add sugar), and white grape juice. Basically the wine at the start is just adding a bit of acidity and flavor.

The most reliable substitution, as @moscafj suggests, is probably just to omit it entirely and increase the quantity of stock.

You can use rice wine vinegar for anything that you would otherwise use red wine vinegar for, or white vinegar, like salad dressings. You could even use it as a substitute for lemon juice, in savory dishes only, carefully. It gives an Asian undertone to flavors, which is quite nice if you're aiming for that. I like to drench dimsum with it for instance.

But it's NOT a substitute for wine. Wine is never that sour. Wine may be what vinegar is made from originally, but the fermentation completely changes its qualities. Parmesan is not a substitute for milk for instance. Just please don't :-).

I wouldn't use vinegar as the wine doesn't really give too much acidity, but I have used beer several times in the past for risotto and it comes out quite nicely. Just don't use too hoppy of a beer as the bitterness will concentrate and leave the risotto too bitter. I like to use Newcastle Brown Ale.

I dunno about rice wine vinegar, but I always make risotto with a little bit of vinegar to omit the wine. I just use a little bit of vinegar (50 - 100 ml ?) watered down to a small cup, and use accordingly more stock.

I do this because I figured it might help with the acidity, although I have never verified it.