Slow Cooker Immersion Dyeing

I've recently (since writing my first immersion dyeing post) learned about immersion dyeing in a slow-cooker. It is not only different enough to warrant a new post, but it's also my favorite way to dye and I think it makes dyeing so much easier and more accessible especially to people who either don't have time or are too easily distracted to closely babysit a simmering pot. You really can't screw things up using a slow-cooker. There is zero concern of accidentally felting your wool. None. Oh, and the best part? That weird wet-dog-burning-hair smell you can get from dyeing wool? That's not an issue with this unless it's been cooking for a while longer than it needs to. Your dye job will be done before you can smell it. I learned that the hard way based off instructions from youtube videos. This is not a 4 hour job. It's more like 2 hrs. I also learned a few other things that were incorrect on various youtube videos and will update the other guide to reflect those changes if necessary.

This is my tiny little dyeing set up in my  art studio . It doesn't take up much space, and I have it ready to go so I can dye at any time.

This is my tiny little dyeing set up in my art studio. It doesn't take up much space, and I have it ready to go so I can dye at any time.

The list of items you'll need (most of which are the same as the other dye guide, so check it out for detailed descriptions and links to some of the items).

  • Slow cooker - do not use the same one you use to cook food. You can usually find them in thrift stores. I recommend those short oval ones over the tall round ones, in a 6-quart size. A smaller cooker would be more than sufficient to dye an ounce of wool and, as needle felters we don't really need to dye copious amounts of wool do we?

  • Slow cooker liners (optional) - I like using one, because it makes clean-up easier. While you aren't supposed to reuse liners between meals, I've safely reused the same liner for several dye baths before I decide to replace it with another one. It'll stain from the dye, but it shouldn't leach into the next dye bath. To be safe I try to do back-to-back dye jobs within the same color range (so don't follow a blue after a red or vice versa). That being said I would still not use a slow cooker after dyeing in it even after using a liner, just to be safe.

  • Large stainless steel bowl - this replaces the tub and colander. I use my bowl for a lot of things and am not really worried about the colander/strainer anymore.

  • Tongs - ones you do not use for food

  • Milligram scale - used to weigh out your dry dye

  • Digital kitchen scale - used to weigh out your wool

  • Acid Dye - I am personally a huge fan of both Dharma Trading Co. and Jacquard. I think Dharma is a bit cheaper. Also, they have more colors.

  • Acid - I like to use granulated citric acid. I'm not sure I'll ever run out of that stuff.

  • Ammonium Sulfate (optional) - this is if you choose to use any premetalized dyes. Many of Dharma's acid dyes are premetalized (which is how they're able to offer so many colors), and while you do not have to use this to dye your wool, you will want this if you want to aim for a mostly even color. Don't get scared off by the word "advanced" - it's just an extra step or two and if you don't use it, it just means you'll get a lot more color variation in the end product. It's a cool effect and we needle felters will find a use for anything.

  • Safety Equipment - things like dust masks and gloves. I wouldn't suggest snorting dye.

  • Glass Jars - how I mix my dye. Syringes are also useful for injecting dye into certain spots if dyeing multicolor.

  • Bamboo skewer - just one. It's very versatile, useful to help stir the dye as it dissolves and poke at the wool in the slow cooker. I've been using the same one for years.

  • Water Kettle (optional) - I dissolve my dye using boiling water. Some dyes pretty much require it.

  • Neutral PH wool-safe detergent - Dharma sells Synthrapol. I use Unicorn Clean.

One other thing I didn't include on the list that you may want to have if you plan on dyeing more than one batch in a day - I have some gallon ziploc bags dedicated to pre-soaking my wool. I weigh out and stuff the wool I plan to dye in the bags, fill with water, squeeze as much of the air out as possible and zip it closed. That way I have several bags lined up ready for the next day. When presoaking your wool, do not add acid. This depends on the effect you're trying to achieve. With some colors you want to wait to add your acid so you can get an even color. If you're doing rainbow and don't want your colors to mix and want them to set immediately, you add the acid at the beginning. 

You don't need to buy special jars, anything will do. Even spice jars. You just need something to dissolve your dye.

You don't need to buy special jars, anything will do. Even spice jars. You just need something to dissolve your dye.

Setting up your dye station

I have a little hand towel set up under my slow cooker to protect the surface and catch any spills and drips. I'm actually using a rolling filing cabinet as my stand since it's in the perfect location - right next to an outlet. On it I keep my slow cooker, my jar of citric acid, the big glass jar I use to both mix the dye and then dissolve and add the citric acid, my skewer, tongs and a measuring spoon (1/2 tsp). If I plan on dyeing more than one batch that day, I have a smaller jar for dissolving the dye for the next batch and letting it sit for a few hours. Having a pair of Ove-gloves is also useful for doing more batch in one day, because that inner pot in the slow cooker is gonna be HOT and you're going to want to dump that water out to get the next batch going. Also if you're sensitive to the smell that comes with dyeing wool (it honestly really doesn't bother me but I know it bothers some people) you'll want to dump it out and rinse it out as soon as it's done. 

Getting your dye ready

You'll need the milligram scale, boiling water, your jar and skewer for this. Dharma discusses how to paste-up the dye first before completely dissolving (click here and click on the instructions tab). Can I just mention for a minute what an amazing resource this is? While youtube was my source of visually showing how it's done so it makes sense, this is really where I learned most of what I know, as well as correcting the misinformation on said youtube videos. I'm not an affiliate, just a fan. Back to the dye prepping, I've both just poured all the boiling water and stirred as well as trying the paste-up method. I personally didn't notice any difference, even with the premetalized dyes. I think the key either way is to let it sit for a few hours and then give it another good stir before adding it to the pot. 

To figure out how much dye I need, I use this free online calculator. If you hate math, I can give you a few basic numbers here. For a nice color, you'll want to use 1%-2% OWG in dye (not sure if that's worded right). Basically you weigh out your wool, and 1% of that weight is how much dye you'll weigh out. The math is actually pretty easy to figure out. 

For 1% OWG if you're dyeing 1 oz of wool, you'll want to weigh out .01 oz of dry dye.

For 1% OWG if you're dyeing 2 oz of wool, you'll want to weigh out .02 oz of dry dye.

For 1.5% OWG if you're dyeing 1 oz of wool, you'll want to weigh out .015 oz of dry dye.

For 1.5% OWG if you're dyeing 2 oz of wool, you'll want to weigh out .03 oz of dry dye.

For 2% OWG if you're dyeing 1 oz of wool, you'll want to weigh out .02 oz of dry dye.

For 2% OWG if you're dyeing 2 oz of wool, you'll want to weigh out .04 oz of dry dye.

If you choose to mix your primaries and get cool colors, just make sure that the total of the dyes add up to the total % OWG. So if you wanted to dye 1oz of wool a simple green at 2% OWG, do .01 oz of blue and .01 oz of yellow, and that'll add up to .02 oz total.

The only time this is a bit different is for really really really really dark colors. Dharma recommends several of their dyes to be dyed at 4% OWG to match the color on their chart (noted on the site). Keep in mind which black you purchase if that's one that you need. The true black is premetalized, which will require ammonium sulfate and risks not getting an even color (which if you like a heathered look, not a bad thing necessarily). Their toner black is not.

Make sure you tare the scale with the empty bowl on it before adding your dry wool. Your dye measurement is based on weight of dry goods. Soak it after weighing it out.

Make sure you tare the scale with the empty bowl on it before adding your dry wool. Your dye measurement is based on weight of dry goods. Soak it after weighing it out.

The steps for dyeing a single color

  1. Fill your slow cooker with water, leaving about an inch and a half from the rim (where the lid goes, not the top). Turn it on high.

  2. Add the dissolved dye and stir.

  3. (optional) Add your ammonium sulfate. I do 1/2 tsp

  4. Add your pre-soaked wool, using your skewer or tongs to poke it around and make sure it's all submerged. It's okay to move your wool around, that's not the same as agitating.

  5. Set your timer for 2 hours (update: I now check at 1 hour, add citric acid then, and turn it off to cool).

  6. Work on your needle felting project, binge watch a show on netflix, get some cleaning done, waste your time on social media or watching youtube channels, read a book, etc. It's your time. Feel free to peek in and poke around your wool. If you're using a premetalized dye, it's a good idea to gently stir it a bit, but it's not the end of the world if you don't.

  7. When the timer goes off, use your jar to skim some of that hot water, add 1 tsp of citric acid (1/2 tsp should be enough I think, but more acid really makes sure it exhausts), dissolve it in the jar and try to pour it around different areas of the pot. Turn off the heat.

  8. Your dyebath should be clear or mostly clear in 1/2 an hour. That's it. If you've got stuff to do, this was the only dye lot you were planning on getting tone today, you can leave it in there to cool off until you can get back to it.

racka locks - star magnolias

Steps for dyeing multiple colors in the same pot (dyeing locks)

  1. Add your wool in a thin layer, add enough water to just cover it and set it on high. Take a little bit of the water, dissolve citric acid (1/2-1tsp), and pour over the wool. Let it get hot. The faster your dye sets up, the less the dye is going to mix in the pot, and you need heat and acid for that to happen.

  2. Sprinkle on your dye where you want it. I want bright, bold, saturated colors, I'm not worried about exhausting the bath, and if I dissolved it first I would be at risk of the colors mixing more than I want. When dyeing a single color for a project I try to be as exact as possible so I can replicate it if I need to, especially if the wool is meant to go in kits. This is more of an artistic process.

  3. I do this in a thin layer, but even with that you risk not getting the dye all the way to the bottom. Come back in about 30 minutes and very gently lift the edges of your wool to see how the dye is setting and if enough dye got to the bottom. If not sprinkle some more in the spots that need them.

  4. Put the lid back on, and try to do your best to wait patiently. I know it's hard.

Dyeing multiple colors (not locks)

Similar to above, but not in a thin layer. You want it pretty packed. Make sure the pot is hot (near simmering) and you have acid in there. You can sprinkle dye on or dissolve and inject with a syringe. For best results, do one color at a time, wait a few minutes and let it set. Blues take the longest to set so start with that color if you're using it (or anything with blue in it). Once it looks like its set, add your next color. And so-on. Flip the wool over to make sure you get any white spots underneath. 

Removing the wool

  1. Using tongs, remove wool from bath into bowl, holding it back to pour off liquid back in. Set aside.

  2. Put on your oven mitts and take inner pot to the nearest sink to dump out, rinse and repeat. Or just dump out and rinse if you're done for the day, or fill if you're gonna dye more tomorrow - then it'll be ready.

  3. Wait for the wool in the bowl to cool off.

  4. When the wool has cooled off, remove it, pour room temp water into the bowl, add a bit detergent (just a dribble), add your wool and gently swish your wool to rinse out. This will get rid of any trapped dye that didn't make it. Pull wool out and set aside in the sink, dump water out, fill bowl with fresh water, rinse wool. I do two rinses.

  5. Put your wool in a strainer/colander and let it drain.

  6. Once you're done, spread out a towel, spread the damp wool on the towel and roll it up. Squeeze/stand on towel to press more water out. Unroll and set the wool aside to dry. This speeds up the drying process.

And that's it! Simple enough, right? Plus, you'll feel productive even if the only other thing you did that day was browse Netflix or lost track of time on social media. Once you get the hang of it, you'll never need to worry about whether or not you have the right color for the job, or enough of it - you can always just dye some more.

update 2/2019

One thing that has helped me speed up the rinsing process at the end is using the Avalon eco-spinner, and a hanging mesh herb drying rack. I no longer need to roll my wool in a towel, and it is usually dry by the end of the day if I dye in the morning.

Another thing I do, is sometimes if the wool is left cooking for longer than necessary, it starts to smell a bit. There’s a fairly short window between the dye being set and when that starts to happen, which is why I now check at 1 hour. It does not harm the wool from my experience, and it goes away after it dries, but to me it’s still noticeable. So when I’m rinsing, I now add lavender essential oil to the rinse water. I think the lavender also helps to keep the wool moths away. It’s one of a few essential oils, cedarwood being another, that deter wool moths, and it smells good. I have never had an issue with wool moths attacking my clean, dry wool, so I can’t give you an official guarantee that it works, but it helps my peace of mind.