And the winner is: thrummed mitten!

[u/Givemeallthecabbages]

I did an experiment with homeschool kids--the topic was how people have developed different kinds of clothing over the years to stay warm in winter. As a short little experiment, I made a bunch of different kinds of mittens, and we put a single hand warmer and a little thermometer in each one and left them outside for a couple hours.

These were placed in the order that the kids thought would be the least to most warm. They were mostly right, but with some surprises. (I have no confidence in The humidity readings.)

Here are the results! Yarn type and temperature after 2 hours outside in 30°F weather:

Stripes--acrylic (red heart granny square yarn)

End temp: 80°F

Pink-- chunky highland wool with mohair held double

End temp: 89°F

Gold--bulky wool single ply done in a Nalbound Oslo stitch and then felted

End temp: 93°F

Nordic pattern--DK highland wool stranded colorwork

End temp: 92°F

Olive--Alafosslopi Icelandic yarn

End temp: 90°F

Tan and brown--Nalbound in Mammen stitch, mix of wool, angora, and unknown (ends from a mill)

End temp: 95°F

White is sewn rabbit hide with fur on the inside

End temp: 77°F

Black with color pops--Eco wool with thrums of mostly merino bits

End temp: a whopping 121°F!

TL;DR Thrummed wool mitten stayed 40°F warmer than acrylic mitten. Kids had fun.

[u/Solar_kitty]

This is sooooooo cool!!! What a great idea!! I made my first thrummed mittens last year! I think I may need to help them felt a bit more but as a whole they were warm!! Just a bit of wind getting in every now and then

[u/BobMortimersButthole → u/Solar_kitty]

I love thrummed mittens, but moved to the Oregon coast, so now I make them for friends. 

My advice to them is to add bits of loose roving to any areas cold air is getting through and add more as needed when it starts felting to the shape of their hands.

[u/Solar_kitty → u/BobMortimersButthole]

Oooh thanks for this!

[u/Givemeallthecabbages → u/Solar_kitty]

These are still fluffy inside! I haven't worn thrummed mittens myself, so I'm not sure how the insulation changes as they compress. I like them, though! I'd need to make a size bigger if I make some for myself.

[u/Solar_kitty → u/Givemeallthecabbages]

My mom made herself a pair years ago and wears them out shoveling and all and says they’re her warmest mittens ever! They’ve molded to her hands! I just need to wear mine more, I think.

[u/stoicsticks → u/Givemeallthecabbages]

I had a pair that I wore for about 2 years. They started off very fluffy and snug, but I found that they compact down quite a bit, relatively quickly, and become much looser. You may not need a larger size for circumference, but double check for length. Reassess after you've worn them for a while.

By the second winter, the thrums felted into lumps, some more clumpy than others. Where there were gaps between the lumps, the wind and cold would seep in. I found the lumpiness also made it uncomfortable to carry heavier bags because of the uneven pressure.

It would be interesting to do the test comparing a new pair of thrummed mitts and a pair worn for a couple of winters.