Using brisket sliced against the grain has worked well for me; I season with only sea salt. It's quite easy to cut this using a sharp knife; the first time I Mage jerky I asked the butcher to slice it for me and he was more than willing, so don't be afraid to ask for a different cut of meat.

I trim the fat- I think it tastes delicious, but my boyfriend hates the flavor of fat in his jerky. I keep my jerky in the fridge most of the time. If You're concerned about rancidity, I would remove the visible pieces of fat and marinate in a bit of apple cider vinegar with some spices and salt for 8-12 hours before dehydrating.

I've also made salmon jerky with just salt that has been great.

As a microbiologist with lots of experience growing dangerous microorganisms in the lab....it's more important that your jerky is either: A) with few seasonings, but completely dry, as in crunchy...to avoid bacterial growth, OR, B) Only partially dry (chewy and moisture collects in the packaging) but then it needs to be cured with salt and nitrates/nitrites, and/or refrigerated and eaten right away.

I make crunchy jerky. That way I don't have to add tons of salt and nitrates. The complete dryness of the meat prevents bacterial and fungal growth. It also helps to dehydrate your jerky at temperatures between 150 and 200 F at some point to ensure all microorganisms are killed.

Like Mike T. said, it doesn't have to be 100% lean, because if you dry the jerky fully, then the fat should render and drip off. If you don't dry the jerky fully, and you don't use any other preservation method (salt, nitrates/nitrites), then expect bacterial and fungal growth, made worse if there is fat (more variety for the microbes to consume).

I have made jerky with a bit of fat left on it (unintentionally) and dried it in an oven on the lowest setting or a bit higher but surely under 200 degreed farenheit . With that said my brother and I finished all that jerkey the same day I made it lol so if it were to go rancid or spoil, We didnt let it. I don't know about buying strips of beef with alot of marbling, and keeping the jerkey for a week. Just buy a lean cut of meat or trim as much fat off as possible and freeze the meat for a bit to make the cutting a bit easier. Hope this helps.

Try to trim as much fat as you can, and if there is a bunch left try and eat the fatty pieces first. Also, though it wasn't part of the question, I love Stubbs beef marinade for my jerky. You should try it because it is awesome.

I have been making jerky for years and have never worried about cutting the fat off. I find that as long as you can keep it out of the direct heat, or in the fridge it will last at least a week if not longer. I have never had any go bad on me in a short period of time and I usually always have beef with chunks of fat on it. Just make sure it is thoroughly dehydrated

If you let it dry long enough, wouldn't all the fat melt and drip off of the lean? In theory maybe you could catch it at the bottom of the dehydrator somehow and then render it and use it for the pemmican?

If you don't let it dry long enough, then you aren't removing as much of the moisture, and it will spoil more quickly. I personally don't think I'd risk 7 days of not fully dried jerky in a hot backpack.

I haven't tried this myself yet but I think it may be worth a shot for trips of this length - since the concern is with the fat in the jerky going rancid, you could probably lengthen the storage time of your jerky by packing it airtight with oxygen absorbers. Example product on Amazon here.

Ensuring your jerky is packed as dry as possible will also help, as will packing in small batches so you're not exposing all of the jerky to fresh oxygen and humidity every time you open the pack.

There's always going to be a little bit of fat in the meat. I dried london broils and meticulously cut off all the fat but the resulting jerky still left an oily residue on my hands when I touched it. I wouldn't leave big gobs of fat on. It probably wouldn't taste very good. But small amounts are probably not a problem at all.

I have made pemmican (with those dried london broils.) I have to admit it was difficult to choke down. One night I melted the pemmican into my rehydrated sweet potatoes and other vegetables. Oh my god, heaven on earth. That was the best backpacking food I've ever had.