Tag Archives: alum

Natural Dyeing Take 3: Black Beans

Having seen some pretty amazing pictures on Ravelry, where a whole thread is devoted to the colour variations obtained with black beans, I have wanted to experiment with those for a few months now. So I was particularly eager to try them out in our dyeing experiments in France.

Unsure about how difficult they would be to find in France, we bought our black beans in Britain before travelling over. I bought a pack in Waitrose which were called black turle beans instead of just black beans, but they were the only ones I could find. Eddie later went into an international food shop and found some labelled simply black beans. We decided to try both out at the same time, but in separate containers in case they didn’t yield the same results…

And fast enough it became clear that the two different packs of beans were giving soaking water of very different colors, despite the beans themselves looking very similar. The Turtle beans’ water was definitely looking more purple while the Thailand Black beans water was a relatively orangey brown.

Two different types of beans, two dye solutions

We were originally planning to use some of the beans for cooking afterwards but forgot that in order to do so the been should not really soak for more than 24 hours… After that the fermentation process starts, and on the second day, we could see some mold on the surface of the water…. probably not safe to eat anymore… I started with the beans in buckets which they only filled to about 1/4 when dry, but even then, after 24 hours they had swollen to about two thirds and I felt I wanted more water to dye with so I moved each of the bean lots to a bigger container, and filled it up with water. Throughout the 48 hours of soaking I would give the beans a stir whenever I walked by them.

Black Turtle bean yarn soup

After about 2 days of soaking and stirring the beans I made sure that they were undisturbed for at least a couple of hours before I took the bean water, so the proteins could settle at the bottom with the beans. Apparently these can ruin the dye. I laddled the water above the beans into buckets. Since we wanted to try small sample skeins and get the same results if we liked them, we used jars for our small skeins, taking enough liquid each time to cover the skein comfortably. I left the skeins soak for 48 hours before taking them out and rinsing them.

For that first try with fresh bean water, the alum mordanted skeins in the turtle bean water gave us a slightly more purpley blue, while the black beans had a slight green hue to the blue. The heuchera mordanted skein gave us a lovely grey but no blue, although I should note here that when I prepped those I hadn’t yet realised the mistake I’d made in measuring the heuchera. This Heuchera mordanted yarn was therefore mordanted only with 1/5 of the strength of the later heuchera mordanting.

copyright Eddieduckling

1. Turtle beans fresh bath, alum mordanted yarn

2. Turtle beans fresh bath, heuchera mordanted yarn (1/5)

3. Turtle beans fresh bath, alum mordanted bath, vinegar afterdip

4. Black beans fresh bath, alum mordanted bath

When we later tried dyeing some more sample skeins in the rest of the dye solution it became clear that the strength of the solution was diminishing as days passed and it was getting less fresh.

copyright Eddieduckling

1. Turtle beans fresh bath, alum mordanted yarn

2. Turtle beans fresh bath, alum mordanted yarn, vinegar afterdip

3. Black beans fresh bath, alum mordanted yarn

4. Black beans 3 days old bath, alum mordanted yarn

5. Black beans 3 days old bath, alum mordanted yarn, vinegar afterdip

I also decided to try dyeing combed top samples which contained some nylon, as I was curious to see how these would take the dye. We placed them in the turtle bean water at the same time as the second round of sample skeins (about 3 days after collecting the water from the soaking beans), but they reacted very differently from the yarn. Although the alum mordanted BFL and nylon mix I tried only yielded a dull grey, the alpaca, wool and nylon mix took on beautiful shades of blues ranging between the tones of the turtle beans and those of the black beans fresh bath.

Once spun up, it turned out a slightly more teal shade of blue, a much more saturated colour than the one obtained on the skeins soaking at the same time.

1. Black beans fresh bath, alum mordanted yarn

2. Black beans later bath, alum mordanted top

3. Black beans later bath, alum mordanted yarn

I always struggle to show the proper colours in photos but do hope that these give a good idea of the colours obtained.

Black bean dyed Alpaca/wool/nylon combed top

I am very partial to blues in general, but I think the colours we obtained from the black beans were my favourite. I always thought blue were quite complicated to obtain from natural dyes, requiring indigo or woad and their long and complex fermentation process. Black beans offer a much easier alternative and I can’t wait to try more different types. I have picked up in a French supermarket some black beans from the US and will be testing those at some point against the ones from Thailand which we used in this experiment.

And of course, the flickr group still holds more photos if you’re interested.


Natural Dyeing Take One: Alum Mordanting with Heuchera Plants

I read in the Ravelry forums that the root of the Heuchera plant was rich in alum and could be used as an alum mordant. Since my mum had quite a few heucheras in her garden that she was going to relocate, I cunningly convinced her to part with a few of the roots. Well, actually it wasn’t all that hard since heucheras are quite willing to grow and spread and you don’t need much of the root for the plant to happily be relocated. They’re usually multiplied by cutting up the roots.

So my mum and I went down to her heucheras for a bit of a cull. She’s not exactly sure of the variety but it is the most common one in France apparently. She also has a few more of fancy varieties, but wasn’t quite so willing to uproot those quite yet…

Heuchera plants (specific variety unknown) before we uprooted them

So I took some of the roots, washed peeled and got a whopping 230g of prepped roots:

Heuchera roots at different stages of stripping

The Ravelry discussion was quoting Nature’s Colors – Dye from Plants by Ida Grae which suggested that ‘two finger-lengths of alum root will mordant about one-half pound of yarn’ (Grae 1979: 53). I measured two finger-lengths and took it to weigh about 15g. What I didn’t realise at the time (and which only occurred to me quite a while after I’d done the whole process of mordanting a couple of mini skeins) was that I’d taken two finger-widths rather than two finger-lengths… mmm… yes, I can be that dumb quite easily… I then recalculated that two finger-lengths should represent about 60g of roots. Of course since no two roots are the same and different people have fingers of varying lengths, this is all an approximation and this is where the experiment begins. I’m taking my stupid error as another point of comparison with only 1/4 of the recommended amount for alum root mordanting. My second batch of heuchera mordanted yarn rectified this mistake. If 60g was enough for half a pound, then 200g of roots could mordant 750g of fibre.

I chopped my roots up and decided to freeze 30g to experiment with later, since the maths would be simpler with exactly 200g of roots left to boil. I wasn’t entirely sure what Ida Grae meant by ‘pre-cook alum root’ so here is what I did: I simmered my prepped roots in a litre of water for about an hour (no, it wasn’t that I didn’t quite realise how long it had been…), then let it soak overnight. Since it had boiled down quite a bit I added another litre of water, and simmered it again the next day for another hour. The liquid was clear to start with, translucent red after the first round of cooking and quite a muddy pink on the second round.

Cooking the roots, before, after first round, after second round and strained

The liquid had reduced quite a bit and once the roots had been strained out, weighed 300g. These 300g contained the alum of 200g of roots, so enough to mordant 750g of fibres. We therefore calculated that 4g of the concentrate would be necessary to mordant 10g of fibre.  To make calculations easier and to be on the safe side we decided on 5g per 10g of fibre. Halving the amount of weight of dry fibres we wanted to mordant was therefore giving us the amount of Heuchera concentrate we needed to use.

France 2011

Unmordanted vs. heuchera mordanted yarn, copyright Eddieduckling

We then proceeded to dilute in cold water enough of our concentrate to mordant our sample skeins. We soaked our sample skeins in water first to get them thoroughly wet, then squeezing excess water out we put them in the pot with the mordant, and set it to simmer for an hour. We then let the wool cool down in the mordant and rinsed it once cool. There was a clear difference in colour between the wool which had not been mordanted and the one which was heuchera mordanted, even with the lot which was only 1/4 of the recommended amount. The heuchera mordant certainly added a dusty pink hue to the fibre.

We still have to test our skeins for ligtht and wash fastness obviously, but the heuchera mordanting definitely reacted differently with the colours from the alum mordanting, as you’ll see in the coming posts.

Photos of our dyeing experiments are being collected in a Flickr group come and take a peek.


Grae, Ida (1979) Nature’s Colors – Dye from Plants. MacMillan Publishers.