How to make rendang beef with a smooth and consistent texture? New to Malaysian cuisine, I recently tried rendang beef and really liked it. In my attempt to reproduce it at home, I followed several online recipes, mostly this BBC recipe. My end result was somewhat disappointing, being very chunky. How can I improve the texture and make it smooth and consistent? I used a generic food processor, one of the cheapest ones in the store. I don't know if a more expensive one would help, but it seems to me there will bound to be chili flakes, lemongrass chunks, galangal chunks in the puree that I prepare in the first step.

Is all galangal super firm and rigid? This was the first time I have used galangal in my cooking, and it was a solid mass of stone that was difficult to cut.

Also, my rendang beef turned out very tart. I wonder if I should cut back on tamarind paste. (I couldn't find kaffir lime leaves anywhere in Atlanta, so I used the zest and juiceof an ordinary lime.)
A cheap food processor is usually just fine for this type of application, I used a stick blender for years to make curry pastes with good results. Although, if it's a really cheap and nasty one it may not do much for you. 

The trick is to chop hard ingredients before blending. Galangal is very hard and will take forever to blend unless you cut it into pieces first. For lemongrass I suggest cutting it lengthways and then cutting into 1 inch or so pieces - bash the fat end with the back of a knife and throw away the pithy hard plug that comes out first.  

As for sourness tamarind is not a universal product, you get different intensities throughout the world so you may need to add less. However, it sounds like you overdid the lime a bit, lime leaves aren't that sour so zest and juice from a lime is a bit much. However, you can add more sugar (palm sugar is great) to balance it out. It all depends on how sweet and sour you want it.