The big drag with many Costco fruits and veggies is that unless you have a huge family or a restaurant you aren't going to use all of the big quantity Costco sells before it goes bad. I have, however, found a way to make the romaine hearts Costco sells in six packs last for weeks:
- Fill your sink with cold water and put the romaine hearts in to soak for about 30 minutes. This re-hydrates them.
- Let the romaine hearts dry for about 20-30 minutes after you soak them.
- Put each romaine heart in its own gallon sized zip loc bag, removing excess air before you seal, and then put them in the refrigerator.
- Every few days eyeball all of the bags and remove any leaves that are starting to brown. Typically the leaf on the bottom starts to brown after a few days, maybe because the weight of the romaine heart is resting on it.
I have no idea whether or not this is considered a good practice from a food safety point of view, and I also have no idea whether or not this ruins some aspect of romaine lettuce that foodies feel passionate about. I do know that I have been doing this for months without getting sick and that the lettuce is still fine by my standards after up to three weeks.
