Using a blender on pears raises one major concern. If you break the seeds, you will regret doing it that way. I chop the pears because if I inadvertently cut a seed I can see it right away and remove the cut parts. You can, of course, halve them lengthways and de-seed them first. I have done this. All it takes is time. Then drop the halves in the blender and puree the pears, skins included.
BTW, use sulphite, not sulphate. Huge difference. Use it early to reduce browning of the fruit. Ascorbic acid will help with this too, but be conservative.
An advantage of chopping fairly fine as opposed to puree is that chopped pears can be contained in nylon straing bags while pureed pears cannot. When transferring from primary, the bag lifts out cleanly and drip-drains quickly -- do not squeeze or you will suffer a clarity problem. If finely chopped, you get excellent flavor extraction during vigorous fermentation. Remove the pulp when s.g. is between 1.020 and 1.010.
If you use a yeast that likes the bottom, stir the wine, wait no more than a half hour, and rack into secondary. You can also stir and simply pour the wine into secondary through a funnel. Worry about racking off the lees later, when fermentation is finished. If the wine is still very cloudy and the yeast is well suspended, simply rack without stirring.
Jack Keller, The Winemaking Home Page
formatting link