Take a piece of the scrap "granite" you want to test and spill a few drops of lemon juice onto it. If you see that under the drops of lemon juice dark spots develop very quickly, it means that your stone is very absorbent and I would advise you against using it for your kitchen countertops.
If it takes, say, a minute or so to be absorbed, then you're dealing with a degree of absorbency that's easily manageable with the application of a good-quality impregnator-type sealer. If it doesn't absorb at all, then you have a winner right there! Go for it, and don't bother sealing it.
But hold on a second! Why lemon juice and not simply water? Because lemon juice is highly acidic, and, if for any chance, the "granite" you're considering is a mixed stone (with some calcite in it), it would etch. That is, it would have a permanent dull spot where the lemon was sitting, after you clean it up. If that's the case, you do NOT want that stone in your kitchen.
Cleaning granite countertops should only be done with specialized cleaners, not Windex or ammonia. The best performing product we have found is MB Stone Care MB-5Marble, Granite and More Spray Cleaner. We have provided this to all our customers as part of a stone care kit when we install a new countertop and when we show them how to care for granite tops the right way.
When dealing with contractors of any kind, quality referrals are your best way to avoid frustration and hassle. And it's why you should consider a referral source like Angie's List to help you find any kind of contractor, not just granite fabricators and installers.
Granite Care Kit Platinum combines the most recommended granite sealer and daily stone cleaner with a proven soap film remover for stone countertops.
Unlike silicon sealers, MB-4 Granite Impregnator Sealer will not evaporate or go through any type of natural deterioration. MB-4 will prevent liquids from being absorbed by all natural stones.
MB-5 Marble, Granite and More Spray Cleaner is your daily cleaner for natural stone including granite countertops. Effortlessly and effectively clean your stone countertops without leaving any streaks.
Platinum Kit provides 1 bottle of MB-4 Granite Impregnator Sealer, 1 bottle of MB-5 Marble, Granite and More Spray Cleaner, and 1 bottle of MB-3 Soap Film Remover!