Ok, as maize and cattle farmer I will try to add some perspective. "Off" mielie pap will have a sour smell. Are you sure that is what you smelled? I have never heard of or experienced something like that. Possible in any way that your domestic worker spilled some porridge or maize meal on the stove before you cooked the meat? You say it was stewing beef, was it only meat or did it still have bones in it? Was it lean or quite fatty? The reason I ask is because if the cold chain since slaughter has been broken at any stage, even only for an hour or so meat especially with sawn through bones start to spoil quickly. (You can prove this for your self by leaving some beef with plenty of bone, like shin, in the fridge alongside a clean cut like rump. The shin will start to "smell" after only a day or two while the rump will stay fresh much longer.) Warm raw fat also picks up aromas of other stuff in it's vicinity more quickly than lean cold meat. What an animal ate during its life, especially the last 3 months before slaughter, will determine the taste, and most of this taste lies in the fat. That is why karoo lamb taste different from freestate and both taste different from natal. The fatty acids in the fat of animals is where a lot of the flavour lies and these are quite volatile. This is what you smell the instant that steak hits the grill. Grass fed vs grain fed: I would guess that 5% or less off beef consumed in SA are pure grass fed. Why? Short answer economics. As cattle farmer it makes sense to sell my calves as soon as they can be weaned to a commercial feedlot. In doing so I am shortening the inter calf period, I carry a lot less risk, and I can keep more cows per hectare. That is why genuine grass fed beef will be much more expensive. On the other hand grain fed does not mean that the cattle only eat corn flakes. Cattle are ruminants and even though yellow maize form part of the ration used by most feed lots they also need a lot of roughage in the form of grass hay or silage. The colour of fat are not so much determined by grass fed or grain fed. It is determined by breed, and to a lesser extent age off an animal. (As a rule of thumb whiter = younger and older more of a creamy or darker hue of white) Classic example of the breed thing is the butter like yellow of the jersey's fat. (By the way if you like your biltong fatty, jerseys makes the best biltong of any breed and that is a fact!) The fat of grass fed beef from the green Natal midlands will most probably be quite yellow, while the fat of beef from the Kalahari or Namibia might be whiter than the fat of beef from a feedlot using yellow maize as energy. Consumer research done by the Red meat producers organization has shown that the SA consumer prefer white fat over yellow and this is taken into account by the different beef stud farmers in the selection of breeding material. The different rations of different feedlots will certainly play a role in the colour of the fat, so I would guess that beef from a feedlot in Mpumalanga where yellow maize is used as energy in the ration should be more yellow than beef produced in the Natal midlands where bergasse (edit spelling?), a by product of the sugar cane industry is used. If the feedlot that your local butcher gets his carcasses from is close to a brewery chanses are that at least a part of the energy component in the ration are dried distillers grain. So next time if your steak has a hint of Castle Lager it might not be your imagination or intoxication! It might actually be true.
