Thanks for commenting, Glenn. It seemed like such an inventive idea when I saw it in the book that I suspected few would have tried it.

re: sunlight, actually, that is what makes this idea feasible... seeds normally sprout underground (i.e., in darkness) so putting the bottle in your pack is great.

There are two practical problems I think of. First, the seeds/sprouts must be kept moist and ventilated, so you have a container of moist stuff in your pack with mesh or porous fabric over the top. I've grown sprouts before but it was a long time ago and I cannot recall how "wet" they need to be, so I am not sure whether this might be a spillage issue or not. Second, I am sure this would work in warm/hot seasons, but wonder what happens when the temps get cooler/colder.

Oh, and while this set-up does not need to be very heavy, it is bulky for its weight (like a 1 qt peanut butter jar with several oz of sprouts in it), so that factors into pack size.

Guess I will need to do more research and some experimentation!

-- Sam