It is water.
It's normal for a car that sits for a long time or only gets driven short distances, especially when the outside air is humid. This would be just moisture condensation. You get rid of it by driving longer distances to let the engine fully warm up and stay hot, for the moisture to evaporate. Like an hour on the freeway. Time for a road trip! An oil change wouldn't hurt either, you can start with that to get some of the moisture out quicker.
It *can* be coolant too, which would indicate a head gasket leak or in case of a watercooled turbocharger, the seals in the turbo. Since your turbo is so new, I don't think the gaskets are suspect.
A shop can pressurize your cylinders (Leakdown test) one at a time and then look at the coolant through the filler hole, a leaking head gasket would eventually cause bubbles in the coolant. (and pressure loss during a leakdown test).
You can also buy your own leakdown tester at any auto parts store, I can't remember prices right now but it's not bad. You also need an air compressor to use it.
So, change the oil, and make a habit of driving the car on a longer trip like an hour or more, one day a week. See if the milky, mayonnaise looking residue goes and stays away.