How to sanitize fruit for wine

I have a pear tree in my backyard and the girlfriend thought it would be cool to make wine with the pears. I have only made beer, so I get confused. I guess a boil isn't used, so how is fruit kept from infecting the batch of wine? Am I missing something?
Or is wine yeast able to takeover before anything else begins to live in the wine?

Most winemakers don't boil the fruit, but instead "sanitize" it with campden tablets (potassium metabisulfite).

What I do is simply freeze the fruit first. That means it easier to smash up when it thaws, as I don't have a fruit press.

Then, when I mix up the must I use 1 campden tablet per gallon of must. I crush the tablet and mix in some hot water (usually 1/4 cup water or so is plenty) and make sure it's dissolved, and add that to the fruit must. Stir well, cover, and wait 12 hours. Then, after 12 hours, I add pectic enzyme. That's not required, but it breaks up the pectin (the stuff that makes jelly) so you can extract more juice as well as prevent a pectin haze in the finished wine. Then, wait another 12 hours, and add your chosen yeast.

Wine yeast is tolerant of sulfites (that's why winemakers use them) but it's still good to wait a while before pitching the yeast once you've used them. Sulfites inhibit the action of pectic enzyme, so that's why you wait 12 hours before adding it. Pectic enzyme doesn't play well with the yeast, so that's why you wait another 12 hours before adding the yeast.

The sulfites added aren't much, about 50 ppm, but it's enough to kill or inhibit wild yeast and bacteria so that your chosen yeast can take hold. The sulfites will disipate relatively quickly, so you can add more (or not) at every other racking as a preservative/antioxidant if you'd like.

The use of 1 campden tablet per gallon of must is used to sanitize, some wines call for boiling the water and pouring over the crushed fruit and letting it steep for a couple days which takes the place of the campden.

For pear wine I would go with the campden or a sulfite solution

Wine grapes are never washed, just crushed/pressed and fermented. Beer brewers have a strange view of fermenting, often they think the must has to be kept entirely free from micro-organisms and if any wild yeast or bacteria get in it will cause an "infection" and the ferment will get tainted. Actually there are always a variety of bugs in any ferment, even beer, but you pitch a yeast so that it will dominate and the others won't cause problems. It is pretty rare for taints to be caused by bugs in the primary ferment, usually problems are caused by something in the winemaker's process eg temperature issues or too much air getting in. The most important thing is keep air contact to a minimum by keeping your containers full to the very top and keeping handling to a minimum. Don't be tempted to open every day to have a look when in secondary, or sample too often.

Greg

Thanks for the replies. Seems like wine making is not at all like making beer. Can I get a recommendation for a good book that explains the basics?

The Joy of Home Winemaking by Terry Garey

Free one here...

"The Home Winemakers Manual" by Lum Eisenman
http://www.winebook.webs.com