by VeggieSue » Sun May 13, 2018 5:14 am
About 20 or so years ago, making potato bags was a big thing for crafters. For one yard of fabric you could make a few of those bags, from small to family-sized. There were swaps on various message boards and everything.
Then it was discovered that if you used the cheaper cotton/poly fabric and batting instead of 100% cotton quilting fabric and filling and nuked your spuds for too long they did smolder and/or go up in flames, especially if you didn't wet the bag first. So people started warning others to use only 100% cotton for the fabric and batting. You were still advised to wet the bag or potato first. The Internet is full of websites with directions on making your own bag in various sizes to this day.
The potato was supposed to have the texture of restaurant baked potatoes - moist and fluffy without getting dried out. You could also warm up rolls and bagels without them getting gummy or rubbery.
As for sweet potatoes - your choice, but *I* never used one. The plain old orange sweet potatoes tend to leak all over, whether cooked in a conventional oven, microwave, even a pressure cooker, every time I cook them, so I wasn't going to take a chance of one leaking all over my potato bag. Maybe a dryer sweet potato, like the Hannah Yams, Japanese sweet potato or batatas, but not Garnets or other orange ones. Others have said they use the bags all the time and never had a problem.
The bags sold in the stores today, like Potato Express bags, feel like they're made with polyester fibers, not 100% cotton. This is probably why they all have warnings on them not to use on high heat or use more than 4 minutes at a time. They're also pretty small - when the box says it cooks 4 potatoes at a time, assume they mean 4 of the small potatoes, like you find in those plastic steamable bags or at most, the size of a dinner roll, certainly not 4 decent sized russets!
Nowadays I toss my russets into the Instant Pot, but if that's being used, I put them on a plate and put one of those plastic microwave plate covers over them and hit the potato button on the microwave and get a perfect potato every time. IDK if the bag would work on these nukers that have the preset buttons, because they depend on the sensors picking up how much steam is coming off the food, and I suspect the bags would interfere with that. I may try it next time with my 20 year old tried and true 100% cotton potato bag.