What kind of dye pot do you use?

Have you wondered what kind of dye pot to use? Does it matter? Can you use one of your kitchen pans? I’m going to share some hints and tips in this blog post.

This is one of the most frequently asked questions I receive:

Why do you dye in aluminium pots?

I generally avoid using aluminium salt mordants (e.g. aluminium acetate and potassium aluminium sulphate), as I don’t like working with fine powders. Alum works as a chemical mordant by helping the dyes fix to the fibres. If we avoid alum, that doesn’t mean that we can’t benefit from the mordanting potential of aluminium. It’s possible to use an aluminium dye pot and have a similar, albeit, weaker effect. (Don’t worry about the “weaker” part, as we can do some other things to help improve colourfastness.)

Since we need to use a dye pot of some sort, we may as well choose one that's made a "useful" metal. This is why I like to use aluminium for most of my dyeing. I don't cook food in aluminium because it’s a reactive metal; whatever is cooked in the pot will most likely contain trace amounts of aluminium, and we know that it’s not healthy to ingest this metal. However, the reactive nature of aluminium is a useful feature for dyeing. This mordanting technique is called pot as mordant.

Above: dyes from acorns (brown), avocado skins (pink) and marigold flowers (yellow).

What is the “pot as mordant” method?

The pot as mordant method is where we carry out the mordanting in the dye pot, at the same time as dyeing. Typically, dyers will treat fibres with some form of alum before dyeing, which is called premordanting. As you may know, I like  to pretreat fibres in soya milk, then I use an aluminium pot to dye fibres.

An aluminium pot won’t be as effective as using alum, as the action is more random. Some of the dye particles will be attracted to the sides of the pot, rather than the fabric. However, I find that using an aluminium pot makes enough of a difference to be worthwhile, and I've continued using this method for years. Also the brightening effect of using an aluminium pot cannot be dismissed. The dye colours speak for themselves!

Above: Discussion about dye pots in Botanical Colour at your Fingertips (also available as an eBook).

It must be noted that I don’t use the pot as mordant method as my only technique for making long lasting colours. As described in Botanical Colour at your Fingertips, you’ll see that I also recommend dyeing fibres slowly, to achieve deeper and longer lasting colours. I don’t just dye for an hour, then rinse. I like to gently simmer fibres for longer periods of time, then leave fibres soaking sometimes for days at a time, and reheat on a few occasions. To sum up, time is a useful factor to work with.

I also use soya (soy) milk as a pretreatment, which you can read more about in this other blog post.

Finally I make use of tannin rich dyes -- this last point deserves a blog post to itself in the future! As we can see, there are lots of factors that we can work with to achieve long lasting colours.

As I hinted earlier, aluminium brightens dye colours and in my experience it can help shift dyes to new and exciting shades. For example, on several occasions I’ve made green from fresh spring time nettles in my trusty aluminium pan. I've never replicated this colour in stainless steel — it simply results in a duller tan. Avocado dye is another one that benefits from aluminium, and I’ve made the rosiest of pinks in aluminium dye pots.

Tips for identifying aluminium pans when shopping in secondhand shops?

Aluminium is duller than stainless steel, so look out for pots that have a matte, satin or brushed finish, especially on the inside.

Also aluminium is lighter in weight than stainless steel.

Generally, once you’ve seen one aluminium pot, you’ll get a good sense of what it looks and feels like, and you’ll be able easily spot them in the future!

Can we use stainless steel?

Yes, of course. You can dye in any kind of dye pot, but stainless steel is non reactive so won’t have any effect on the fibres, either in terms of mordanting benefit or brightening colours. I tend to use stainless steel pots when dyeing with tannin rich dyes, such as alder cones (shown in photo below).

Photo by Siobhan Watts

Do I need to buy a special pot for dyeing?

No, use what you already have, or what you can get hold of easily without spending too much money. You can start off with stainless steel, if that’s what you have, then perhaps look for an aluminium pot later on. If you dye slowly, like I mentioned above, then this will help you develop deeper and longer lasting colours.

Just don’t use your cooking pans for dyeing — I’ll go into this more in a moment.

What about enamel pans?

Enamel pans are made from coated metal, so are non reactive, just like stainless steel.

What about iron and copper?

Iron and copper are both reactive metals and will have an effect on your dyeing, both in terms of mordanting and the final colour. Iron will deepen or sadden dyes, and copper will bring out yellow and green shades. Both of these metals are very useful.

I often use iron (or rust) water to dip dyed fibres to darken colours. As an alternative, you can do the entire dyeing process in an iron pot. You’ll see your dye gradually darken and the fibres will dye a deep shade.

Look out for second-hand iron or copper pots that are uncoated.


Above: the effect of iron on different dyes — acorns, avocado skins and marigold flowers. In each pile of swatches, the darker fabric was modified with rust water. You can get the same darkening effect by dyeing in an iron pot.

Can we use kitchen pots for dyeing?

I never recommend using kitchen pots for dyeing, unless you’re working with something entirely edible, such as berries or tea. This is the only exception. (For tea dyeing, you'll love this other blog post -- I show you how to paint patterns with milk and dye with tea!)

The best practice is to use a separate set of equipment reserved for dyeing. Some plants are toxic, or have the potential to cause digestive problems, so please don’t risk contaminating your cooking pots.

Thanks for reading!

Did I miss anything in this blog post or did your question go unanswered? Email me with your suggestions! If there are any other topics you’d like me to write about, please get in touch via email and let me know!