I never ground meat for hamburgers. I have a Kitchen aid mixer with
the grinder and pasta extruder attachment. I think I can figure out
how to use it, I have made pasta with it, but what I don't know
anything about is what to buy.

The last two times we had BBQs, we used ground sirloin from this local
place that had it on sale for $2.89 and $2.69 a pound. Boneless
sirloin on sale is usually about $3.99 and Fairway has prime sirloin
for london broil at $4.99.

So, how do they get down to $2.89 and $2.69. What do they add to it
to bring down the price? This ground sirloin was 92% lean. Could
that be from a peice of sirloin for london broil. What am I missing
here?

I really like the taste of sirlon, so is there anything I should add
to a piece of sirlon london broil to get the fat content down up to
10% or 90% lean.

What is the difference between sirloin and top sirloin? Is prime
sirloin better than choice top sirloin? What are the differences?

Alan