When bringing your own reusable bags for produce that needs weighing, what's the lightest option?

Question

When purchasing fresh fruit and veges and other foods from the supermarket that are weighed during check out, I have tended to use the very thin plastic bags provided (when it's necessary to use a bag at all) because if I use my own cotton bags I'll pay extra for the privilege due to the heavier weight of the cotton.

It's not a realistic option in this case to zero the scales first with the empty bag sitting on the scales. The extra cost of using my existing cotton bags would be substantial when the produce has a high price per kilogram. eg if the bag weighs 20 grams, and I'm purchasing something at $5/kg, I'll pay about an extra 10 cents for each bag used, assuming the weight of the thin plastic bags is negligible.

It's also not a realistic option to reuse the thin plastic bags; they simply aren't very durable.

Which reusable materials/fabrics could be used for replacing these bags to minimise any extra cost? Silk is pretty light, but I'm not sure how long it would last, and there might be other options that are cheaper or more sustainable.

Answer 1

I prefer to cheat - I use the disposable bags brought home by my housemates. One way or another our household seems to accumulate enough plastic bags that there's rarely a shortage, and if there is my workmates could easily fill it. So the simple option would be to look for a source of plastic bags that you can re-use.

My local supermarket will happily weigh most larger things without bags at all, as long as there's only a few of them. So I can buy 3-4 onions, 3-4 apples, and so on without bags. I often do that. Likewise, for less perishable items (rice, beans, potatoes) I buy a larger bag rather than loose items (to be honest, I do this because it's cheaper), and those bags are often usable in the garden afterwards, or can be returned (reused) or recycled (the rice co-op recycles the bags into new bags).

What our food co-op does is encourage people to weigh their containers before they fill them so that a net weight can be established. This works because it's a fairly small shop and (almost) everyone plays fair. I suspect that a supermarket would not do this, except perhaps with things like peanut butter that really have to go into a jar.

If you're going to make the bags, I suggest rip-stop nylon. It's almost as light as silk but more durable. You could also optimise the shape somewhat by making triangular or rectangular prism shaped bags rather than simple pouches. Also, don't put drawstrings or anything on them and keep the hem widths small. But the question there is whether you'd use more resources with the nylon that you'd save by re-using other people's plastic bags.

Answer 2

Firstly the plastic grocery bags that the stores give/sell you are awfully light. I just weighted 4 on my kitchen scale. They average 6 grams each. This means if you buy stuff a pound at a time, it's just over 1% extra. At a kilogram you are down to 0.6% extra.

Secondly: the bags are tough enough to get home, and we often reuse them for other things. So, as long as you aren't hauling rocks in them, I would expect to get a half dozen uses each.

Thirdly: They only have to last long enough to go over the scales. You can transfer them to your cloth bags as you bag your groceries.

For stuff that is either sharper or you want to buy in larger quantities, recycle the red mesh onion bags. (Obviously a bad idea for split peas or bulk couscous...)

Finally for stuff that keeps, buy it prepackaged in the largest size you can store. We buy flour in 10 Kg bags, and store in a non-operating chest freezer in a shed. (Old freezers are great mouse proof storage.) Ditto sugar.

One local chain has bins outside where you can return your plastic bags to be turned into fence posts. No reason you can use them for another round trip first.

Answer 3

I would like to suggest you also look into recycling very light, maybe sheer, window curtains as the material for your own homemade bags. Just one from a yard sale could make enough bags to last you for quite a while, and if you do a good job of hemming them and finishing the edges, you could probably machine wash them in a protective mesh bag, as you would lingerie.