When making hummus the other day I noticed that it’s gotten grainier in the past year, and I’m starting to suspect that the food processor knife is to blame. The machine is getting on in years (fifteen, I think, so it’s possible that this particular model has been taken off the market) and the blade has started to look rather notched. Google gives me to understand that blades can indeed be sharpened using a whetstone, but as usual, it’s hard to find reports on the result. What say the Café Society Dopers?
I’m sure you can do it with mixed results, but you might want to see if your local hardware store sharpens knives.
Otherwise, it’s probably easier to just get a new one. Take a look at their website and see if they sell replacements and/or check RepairClinic.com to compare prices. You might find it’s only $10 or $15 for a new one.