That's what I thought. Easy. One year into research and product testing; not so easy.
It's hard to find a product that is not only reusable, but also durable. I experimented with several brands of reusable ziplock bags. Over all, I wasn't impressed. After two months on rugged expeditions, in Brazil last spring, the plastic began to separate from the zipper, the seal wasn't as sound, and there were a few holes. They were way more durable than a regular ziplock bag, though I expect their life span wouldn't last through too many expeditions. Lastly, the higher price tag doesn't make them appealing for a long expedition in need of 150 bags.
Next option. I'll just make my own. Easy right? Ha, no. I'd like to offer a big thanks to all the moms who have worked to make reusable food safe snack bags. Their research became my jumping off point.
First- What is the purpose of a food bag on expedition? It keeps food dry. It's not breathable- it doesn't allow dried food to absorb moisture. It needs to be durable. Weight matters.
Second- The material has to be food safe. This has been challenging to address. This is where those snack bag making moms were a big help.
Third- Construction. Sewing is the most practical. However the seams of a waterproof fabric quickly become not waterproof when sewn. Sealing them opens the door to a huge amount of research- food safe adhesives or seam tape that adheres to said fabric. This question led me down a rabbit hole into the world of industrial food packing adhesive manufacturers. Then I began to ask is seam sealing worth it?
Step Four- Testing the first prototype. I'm not 100% satisfied with the product. The seams aren't sealed, the fabric is different than I expected. They are food safe, machine washable, the fabric is waterproof (up to 300 washes), and they're not too heavy.
Fifth- Keep researching! I'm still investigating more materials and construction methods.