In a uniquely Scottish crime against yarn, I decided to see if I could dye wool with only the power of the Scottish national drink, Irn Bru.

Irn Bru is (like most fizzy drinks) full of food colouring and citric acid, which in theory are all you need to dye protein fibres. So in this Instructable we're testing the theory 'Will it Bru'.

Supplies

Irn Bru. I initially used one 330ml can, but then went back in with a second
Yarn. I used a 10g mini skein of merino/nylon blend sock yarn
Heatable dyeing receptacle. I used one of the glass beakers and steamer I use for regular dyeing, but as we're only dyeing with Irn Bru it won't matter too much if you use a regular saucepan

Step 1: Prep and Soak Yarn

You want your yarn to be in a skein (big set of loops), and tied in at least three places, to prevent tangling. My skein was only tied in two places, so I made a figure of eight shape through one portion of the skein, and knotted with spare yarn (keep your figure of eight nice and loose, if you strangle the yarn it creates a resist and won't dye evenly).

Soak your yarn in warm water for half an hour, and in the meantime boil a kettle of water.

Step 2: A Lovely Bath

Pour your Irn Bru or chosen national drink into your chosen receptacle (in my case, a beaker in the top half of a steamer). Sipping at small quantities of any remaining Irn Bru, think back to your childhood as you immerse the yarn in dubiously orange liquid. As I discovered, yarn floats in Irn Bru, so smoosh it down into the liquid with a spare kitchen utensil.

With acid dyes and food colouring dyeing, you can add as much water as you like to your bath: it's the quantity of dye that matters, not the concentration levels in the water (so 5g of dye in 100ml of water will dye to the same intensity as 5g in 1000ml), so if you're using a large receptacle feel free to add water to help submerge the yarn evenly.

Step 3: Heat

Heat your lovely soup until the liquid turns clear, then an extra 10 minutes to be safe. I found my yarn dyed *really* quickly (within 10-15 minutes), probably because there was so much citric acid.

Step 4: Rinse Rinse Rinse

Once your yarn is dyed, you're going to want to do a *lot* of rinsing to get all that sugar out. Pour away your now dubiously clear and yet still-smelling-of -Irn Bru liquid, and start rinsing your yarn in warm water. I did a few rinses in plain water, then with washing up liquid/dish soap, and then plain water again. As you can see, the dye doesn't leak out into the water, so we can happily say it's colourfast.

Just to really get rid of any residual Irn Bru, I also heated the yarn in a panful of water on the hob for ten minutes. You can skip this and just do lots of rinsing if you prefer.

Step 5: Dry

After rinsing, gently wring out your skein of yarn, lace both hands through the loops, and yank your hands away from each other in a snapping motion. This helps realign the strands, so it won't tangle when you wind it into a ball for using.

Lay it out or hang it to dry, and twist into a skein again once dry.

Step 6: Bonus Repetition

This is my skein after one can's worth of beauty treatment. I decided this was a bit pastel for my tastes, so I repeated steps 1-5 with a second can for a stronger colour.

Step 7: Conclusion

Here is my mini skein after a glorious two cans. Conclusions:

Irn Bru absolutely works as an all-in-one dye for protein fibres
At 2 cans per 10g of fibre for a decently strong colour, it's not the cheapest of dyes (if I was actually in my native Scotland, I would absolutely be experimenting with knockoff brands such as Iron Brew etc. because those are things that really exist)
This was a fun and successful experiment, requiring no specialist equipment. Probably a fun thing to try with kids

I'd love to see other people try this project with their locally popular fizzy drinks, so lemme know if you try!