There are 3 conditions that could cause white smoke !
1. Water in the combustion chamber
2. Misfuel.
3. brake fluid.
Have a look at the master cylinder and see if the level has dropped
4. Normal combustion. Coupled with a cold exhaust system, and cold, moist air just beyond the tailpipe.
If I was a betting man, I'd put money on you having started the engine and run it for a few minutes every few weeks, while it was off the road?
The trouble with this is that unless the exhaust system gets properly hot, it will collect condensed water each time the engine's run for short periods.
I did some rough calculations this week, and, surprising though it may sound, a petrol (or diesel) engine makes around 1 litre of water per litre of fuel burnt. The basic chemistry is fuel + oxygen = CO[size=8]2[/size] + H[size=8]2[/size]O.
Obviously, inside the combustion chamber this 'newly created' H[size=8]2[/size]O is in gas form (steam), but once it cools in a cold exhaust system, it becomes, for want of a better description 'cloud'.
