I’ve read about oak galls and their place in dyeing and ink-making a little, and didn’t think too much of them – I don’t really think of oak trees in Calgary (compared to trips to Louisiana!) but while out for a walk (playing PokemonGo!) I noticed that one of the parks near me had cute little (young) oak trees. A closer look… and there were the weird clustered balls.
According to the city parks website, I’m pretty sure these are Bur Oaks (Quercus macrocarpa), sometimes called mossycup oak and mossycup white oak. If any of my more horticulturally-inclined friends know otherwise, please let me know!
Now… they’re a LOT smaller than I expected oak galls (also known as oak apples or oak marble galls) to be, but I had my fingers crossed that they would work for dyeing/mordanting. I also don’t know if the galls from Bur Oaks will be as high in tannins as from other varieties of oak… but hopefully still enough to get good results.
More photos of what I expected oak galls to look like on Wayne Armstrong’s website.
Since it was late summer when I first found them, I was seeing a LOT of green oak galls – without any holes in the galls to indicate that the wasp had vacated. However I did find some that were probably from a previous season or earlier in that season – which DID have the hole, so those were the ones I collected. I’m not sure if “old” galls are better or worse than ones recently vacated. (So many questions! If you know any of the answers, please reply in the comments below!)
A few weeks later I returned to the park and collected even more – (almost) all again with the hole in it (as above). Apparently I’m not the only person on the hunt for oak trees in Calgary, this reddit thread has a few answers (and some of them even have potential!) In the meantime though, I’m carrying a small ziplock bag in my purse… Not only do I want to find the tree- but one with branches low enough to collect the galls from – super tall established trees trimmed to provide a nice shade canopy won’t help much at all!
I also visited a second park with young oaks, but it had almost no galls – I suspect this location sprays for pests, and thus no wasps were there to create the galls.
Even though we’d already had snow, some of the galls were still ‘soft’ and didn’t have the tell-tale hole, so I ziplock sealed the baggie, and then when I got home tossed the baggie in my freezer… to kill off any wasps still inside the gall.
Oak galls as a mordant
I visited Griffin Dyeworks which has a pretty great run down about different products they carry – but also alternatives which were way more interesting to me. For Tannic Acid, they describe it can be used as a pre-dye additive or as a final rinse; results will be different for both. They indicated it will add brilliancy and fastness to some dye colours, and “enhances reds with tin”.
“Mordant (with tannic acid) before using a metallic mordant (copper, iron, tin) to create a good bond with cellulose fibers. Darkens fiber with age. “Antiques” bright colors. Useful as a rinse to neutralize fibers dyed in alkaline dyebaths, such as indigo vats: use 1 tsp tannin dissolved in the rinse water.”
Best On: Especially good on silk, cellulose fibers; not good on wool
Dye Recipe: To mordant with powdered tannin: add 1 tbsp tannin to 1 lb fiber, simmer well-soaked cellulose fiber in liquid 15-20 minutes, continue with dye recipe. To mordant with plant tannin: soak tannin 24 hours, boil without fiber 1 hr, strain to remove plant pieces, add fiber, simmer 1-2 hours or as directed in dye recipe. Add 1/2 c vinegar to last rinse. For darker dye, use more tannin. Renew mordant pot with 10-15% salt, 2% soda ash, 1% Glauber’s salt to weight of tannin. For blue-black color, mix tannin with iron.
Safety: Very dangerous to inhale powder! Use mask and safety goggles; do not wear contact lenses when working with tannin; if powder gets in eyes, wash eyes constantly while someone calls for medical help. California Proposition 65 Warning.
Disposal: Pour on any tree or neutralize with baking soda, pour down toilet or sink
Galls, Oak galls, Gall-nuts: Abnormal growths caused by insects; 60-78% gallic acid. Boil 1-2 hrs: 1/4 lb galls to 1 lb cotton. Turkish galls: 50-60% tannin; Chinese galls: 70% tannin
So really.. it’s only that LAST paragraph that I’m really interested in – the one that talks about alternatives to their powdered tannin product, and instead talks about the oak galls as a source of tannins instead.
In Wild Colour, Jenny Dean writes about oak galls as a mordant as well. While she notes chemical mordants like aluminum, copper, and iron, she also suggests natural mordants like oak galls and staghorn sumac leaves. These are rich in tannin she notes, which helps colour adhere and increases light and wash-fastness, specifically on vegetable fibres.
In addition to acting as a mordant on vegetable fibres, she also notes that oak galls can be used to further improve the absorption of alum and copper mordants before dyeing.
- Wet the fibre by soaking in water between one hour up to overnight.
- Simmer the oak galls (or sumac leaves) in about 4 gallons (18 liters) of water for one hour
- Leave the solution to cool, then strain off the tannin liquid.
- Soak the wet fibre in the tannin solution for 8-24 hours, rinsing well before proceeding with dye or additional pre-mordants.
The oak galls can be dried thoroughly, and then reused for another batch of solution. She doesn’t indicate if the second round will be less potent and need a perhaps higher quantity of galls per liquid/fibre.
Oak galls as a dye
Jenny notes that no part of the plant requires a mordant, and to use equal parts of dyestuff and fibre for bark, leaves, acorns, or galls. Small amounts of iron modifiers gives “attractive greys” she notes. Harvesting time for the leaves also impacts colour, with fresh leaves collected from windfall producing brighter colours, and fallen autumn leaves (either used fresh or dried) producing brown shades. I was reading this in mid November, and all the leaves had long fallen to the snow, but this might be something to try next year…
Preparing my galls
Mordanting with galls
On December 5, eleven days after soaking the galls, I poured the mixture of galls and snow-water into my dye pot, and added enough more melted snow water to immerse my yarn and fabric for mordanting. I turned the heat on slowly, warming the mixture for about 30 minutes (with my stove at 4/10). Then I increased the temperature to just under a simmer (6/10) and kept it there for about an hour. Then I let the mix completely cool on the stovetop.
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