I have white wine in my wine fridge from 2007. Will it be drinkable?
"Drinkable," yes, but in all probability it's well past its best-before date, like the open jar of mayonnaise I've had in my fridge since about the same time. You didn't specify the particular brand or style, so it's impossible to offer a conclusive verdict. But most whites would have succumbed to the less-than-ideal conditions of your refrigerator. A fridge is cooler than ideal cellar temperature. At roughly 4 degrees C (typical fridge temperature), versus the 13-degree ideal of a cellar, reactions that can spoil wine slow down considerably, meaning that your wine will in principle not have evolved much. That in itself is not a bad thing.
However, a fridge's main compartment is very dry (in contrast to the vegetable crispers, which are designed to be more humid). That arid environment, at less than 50-per-cent relative humidity, will dry out the cork, permitting liquid to evaporate through the cork and air to seep in to fill the void. Oxygen is your enemy here. It bruises the wine and leads to off-flavours. White wines are particularly susceptible because they are generally fermented without skin contact, so they don't have the skin tannins that provide antioxidant support to reds.
For this reason, I would recommend storing wine in the fridge for no more than a few months. If, on the other hand, your white was sealed with a screw cap, you might be in luck. Screw caps provide a much tighter seal against airflow.
There's only one reliable way to find out: Try the wine. If it's a pinot grigio, sauvignon blanc or chardonnay and tastes more like sherry, it's not in good shape. You can still safely drink it (it won't harm you like bad milk or cream). Just don't expect guests to lap it up with gusto at your next dinner party.
The Flavour Principle by Lucy Waverman and Beppi Crosariol (HarperCollins) won top prize for best general English cookbook at the 2014 Taste Canada Food Writing Awards.