Judging solely by the names — spare and baby back — you would naturally assume one rack of ribs is smaller than the other, and that assumption would be correct. (Though if you assume one of them is ...
Fat means that the ribs have a good flavour so look for marbling throughout the meat and the ribs should be a pink-red colour. The key to good ribs is to marinate them well and cook them slowly ...
For the ribs, place the rib racks into a large, wide, heavy-based saucepan with the celery, onion, chillies, garlic and apple juice. Pour over just enough water to cover the pan contents.