Need fake beans, need hot, fake beans.

January 22, 2008 1:02 AM

Beans! I want to make a microwavable beanbag, something that I can nuke for 30 seconds or so and wrap warm around my neck - but I don't want to use beans.

I've seen the handmade ones with cherry pits, aduki beans, pearl barley, etc, but I'd like to make one that won't attract bugs or mold. Is there a synthetic equivalent I can use?

posted by roygbv to grab bag (28 comments total)

What about ceramic pie weights?
posted by clh at 1:34 AM on January 22

Does rice attract mold? I used to use rice.
posted by sully75 at 1:37 AM on January 22

Flax Seed is what you seek.
posted by Aquaman at 1:43 AM on January 22

There used to be a product advertised on TV called the SobaKawa Neck Pillow, which was a cloth bag which was bigger at the ends than at the middle, and was filled with buckwheat hulls. It was advertised as being microwaveable, so it could be heated up for 30 seconds to 1 minute (I think) and it's deep heating warmth would relax muscle tension, and create an overall feeling of well-being. Or so it was claimed...I also recall this product being available in Daiei department stores here in Hawaii, so it may be worthwhile to search the web and see if it's still available.

P.S. Soba Kawa translates to Buckwheat Pillow...at last, truth in advertising.
posted by motown missile at 2:09 AM on January 22

Rice.
posted by orthogonality at 2:14 AM on January 22

I have had one filled with plain white rice for about 15 years now, and it hasn't ever attracted bugs or gotten moldy. I always figured if it did get messy in some way, I'd just open it up, wash it, and put in new rice (which is really cheap), but it's been used a lot and not gotten messed up in any way in all this time, even though it has spent it's whole life sitting on the back of my couch for regular evening use. Also, it seems to hold the heat longer than any of the others I have had.
posted by Orb at 2:24 AM on January 22

BTW I feel like mine lost its ability to hold heat after a while and I thought that was because the rice dried out. Which doesn't make any sense but that's what it felt like. Initially the heat seemed to be a moist heat, then it slowly was drier and less warm.
posted by sully75 at 3:21 AM on January 22

Rice is so easy and cheap, just toss it if it develops a problem. You don't need to make an elaborate cover -- a sock will do. If it dries out too much, as sully75 says, then dampen it a bit. (Yes, you can wash it, too.) Toss in some lavender, or add a little essential oil, if you prefer that to a slight smell of rice.
posted by Idcoytco at 3:40 AM on January 22

I use wheat. 2lbs of wheat in a bag, nuked for up to 4 minutes.

Sully75, the same thing happened to me. Sprinkle a bit of water over the bag and let it soak in before you use it. Every time you heat it, the water evaporates a bit. Putting it back in revilatises the bag.
posted by Solomon at 3:42 AM on January 22

I thought of buckwheat hulls, too. Unfortunately this site indicates that buckwheat can suffer from mold. Personally I would go the flax/rice route and toss it if you have problems, as Idcoytco recommends.

If you really want non-food materials, Pyrex in small sizes would be microwave safe. It looks like a lot of bead artists make/use boro (borosilicate = Pyrex) beads in their work. It seems an expensive route to go, but you could buy a bunch of arty boro beads and use those. Or chat with them to see where they get their raw materials.
posted by cocoagirl at 3:55 AM on January 22

I don't think your suggestion will work, Cocoagirl.

Microwaves work by exciting water molecules. Water is a dipoar molecule - one side is strongly positive and the other side is negative. The microwave oscillates its polarity rapidly, making the water molecules shake rapidly, which effectively heats the product. Something that is not polar and contains no water eg a microwave safe glass like Pyrex, will not heat up in the microwave. You need something in the bag that contains small amounts of moisture - hence the wheat or rice.
posted by tim_in_oz at 4:18 AM on January 22

I thought that was because the rice dried out. Which doesn't make any sense

actually, that makes perfect sense. microwave ovens work mainly by making the water molecules in your food rotate; this is because water molecules have a high dipole moment. if you stick something really dry in the microwave, it won't get very hot. for this reason, i dont think glass beads would work very well.
posted by sergeant sandwich at 4:22 AM on January 22

Here you go - A Tutorial!

Rice Heat Therapy Bag with Washable Cover
posted by Corky at 4:35 AM on January 22 [1 favorite]

@Sergeant Sandwich I said it made no sense because it happened over a long period. I would figure that whatever moisture that was in the rice would dissipate quickly in the microwave. What says you?
posted by sully75 at 5:24 AM on January 22

I use one filled with corn. It gets pretty hot and holds its heat well.
posted by konolia at 6:33 AM on January 22

I would figure that whatever moisture that was in the rice would dissipate quickly in the microwave. What says you?

I, too, have a homemade one filled with rice. It seems like a little bit of moisture comes out every time I heat it, so I imagine the residual moisture of the rice will run out eventually.

If you've got a sewing machine, it's SUPER easy to make a little pillowcase (or 2!) when you make the warmer itself, and then you can wash it more easily. I always wonder whether the heat of the rice bag makes my skin underneath sweaty, so I like to keep the cover clean.
posted by vytae at 6:42 AM on January 22

My wife has one filled with buckwheat hulls, and it's as good as new after 10 or more years of use.
posted by deCadmus at 7:22 AM on January 22

Can I slightly derail by asking if any of these options will NOT smell like dirty socks, bringing my microwave along for the stinky ride? I gave up on all such things when the smell drove me mad.
posted by rokusan at 7:41 AM on January 22

My wife has one that has flax seed plus some cinnamon and clove and other spices. This works well and smells nice. The spice smell gradually fades with use, but if you have made the thing yourself, you can always add more.
posted by Lazlo Hollyfeld at 7:53 AM on January 22

Field or deer corn works really, really well. It has a pleasant corn smell but you can put the bag inside a ziplock to kill the smell while heating. The person I linked to kindly provides directions for making the bags and information about fire hazards and use of the corn bags in hospitals.
posted by hecho de la basura at 8:33 AM on January 22 [1 favorite]

Seconding Deer Corn.
posted by lyam at 8:38 AM on January 22

I make them with rice and store them in the freezer (so they're a ready ice pack if something hurts/swells, and can still be microwaved for heat). I haven't ever had any problems; the oldest one I had before I tossed it to move was several years old, and the oldest one I made that's in my mother's freezer is probably 10-12 years old.
posted by Cricket at 9:04 AM on January 22

rokusan- some of them have some lovely stuff in them that smells great: I made mine with dried eucalyptus and lavender, which ends up smelling oh so good.

To answer the question, what about sand? It isn't synthetic, but it may allay your concerns about mold.

How about salt? That certainly won't mold, and optomotrists use that to fix glasses.

How about silicone beads? They use them at 4eyes to bend glasses by heating them gently. Couldn't find any sources for you, tho.
posted by arnicae at 9:44 AM on January 22

I bet silica gel would be the ideal filler for such a pillow. The water content if you leave it out in a room in ordinary conditions is more than enough to make it heat up in the microwave. Every time you heated it up in the microwave it would dry out a bit, but it would recharge itself by picking up moisture from you and the ambient air when you used it. It's non-toxic (silica dust is dangerous to breathe, but I think dust from a pillow with a tightly woven cotton cover would be minimal) and you could easily sterilize it-- it would in fact probably be self-sterilizing in a microwave.

As an extra added bonus, when silica gel does pick up moisture from the environment, it heats up dramatically, so the heat from a thoroughly microwave dried silica gel pillow would be (I suspect much) longer lasting than one from other materials with comparable heat capacities.

The last time I bought it as a dessicant, I think I paid around $17 for a can containing several pounds.
posted by jamjam at 9:50 AM on January 22

I don't think your suggestion will work, Cocoagirl.

Oops, yup. The whole reason Pyrex is m/w safe is because it doesn't heat up. I lost sight of the OP's actual goal.
posted by cocoagirl at 10:18 AM on January 22

Years ago I filled a tube sock with rice, tied the top closed with a string, and voila! Never have had a problem with smells or mold and this "Rice Rat" when heated in the microwave is good for both muscle issues and fantastic for clearing your sinuses when fighting a cold.
posted by donovan at 11:11 AM on January 22

nthing deer corn - my aunt makes these stuffed with deer corn, I hate the smell but it works.
posted by Lizc at 1:13 PM on January 22

nthing the rice.
I keep a sock full of rice in my camera bag in humid places. When It's not in the camera bag, it's often being microwaved to put on my knees.
Incidently, if you use it to absorb humidity under really humid conditions, like a rainforest, you can dry the rice out a bit by untying the sock and toasting the rice a bit in a dry skillet.
posted by piedmont at 3:15 PM on January 22