Look, we all know a juicy, fatty steak is scrumptious if you need grilled or pan-seared meat. That wealthy marbling imparts an unimaginable taste because the fats breaks down, however that is the worst potential factor for jerky as a result of the whole level of the jerky-making course of is dehydration. You need to get as a lot moisture out of the meat as you presumably can, which not solely lends beef jerky its signature texture, it retains it (if you happen to actually nail the method) shelf-stable, which is why it may final for thus lengthy.
Fats, in the meantime, accommodates a complete lot of moisture. The extra fats in your minimize of meat, the more durable it is going to be to get the moisture out of your jerky, making it far more more likely to spoil. Along with the spoilage issue, fats will get slightly bizarre if you dehydrate it. It is meant to be rendered at excessive temperatures somewhat than have its moisture sucked out, which leaves fatty jerky exhausting and unappetizing. This implies the cuts to keep away from are issues like ribeye, tomahawk, T-bone, porterhouse, or New York strip; all of those have a fats content material method above what you are on the lookout for in dehydrated deliciousness.