What can I substitute for dry white wine

In general, dry white Vermouth is an excellent substitute. In fact, the venerable Julia Child almost always used it when a recipe called for white wine. It keeps better/longer than white wine, once opened, for starters. plus, the herbs infused in it add interest to almost any dish.
Otherwise, I would say it all depends upon the dish you're looking to sub the wine in - as well as your reason for subbing.

After a long and frustrating search for wine substitutes, I finally got up the nerve to create “wine bouillon” and it’s proving a good substitute for wine in many dishes.

Essentially, I’ve flash-dried wine into a powder that contains zero alcohol, no salt or preservatives...and all the flavor of wine. I’m calling it The Dry Gourmet. We’ve produced a red and a white. (Bourbon and rum are in the works.)

Currently, we’re only selling on our website (www.drygourmet.com).

Initial results have been great, with many home cooks creating their favorite dishes with all the flavor of wine.

Please drop me a line if I can answer any questions about this wine substitute.

Thank you.

Ben

Depends on what you are making and why you ask. If you simply don't have dry white wine in your larder and you are trying to flavor a sauce or deglaze a pan, then chicken or vegetable stock will work. If you are just seeking an alternative flavor, then white vermouth or sherry would work. If you want to avoid alcohol, then chicken or vegetable stock or just plain water would be fine.

Dry Vermouth is my kitchen staple. Sherry is a close second, but adds some sweetness so decide based on your recipe.

White dry vermouth is your best friend in both kitchen and martinis.

Dry vermouth would be fine. If cooking to reduce, then plain chicken stock.

What's the recipe you're making?