Monday, January 16, 2017

Buckthorn with vinegar, twice in 2016

In 2016 I tried twice more to get green for paint or dye/stain from buckthorn.

Bolognese MS De Tintis ad Tigendum Pellum (Merrifield 426)

2016 Vinegar and buckthorn:  On September 24, 2016 I tried with Organic Spectrum brand white wine vinegar (diluted to 6% acidity by the manufacturer).  Heating in my corning ware experiment sauce pan caused the vinegar to simmer, steam and evaporate.  It was so strong I had to leave the area repeatedly to let it reduce to half.

bubbling and steaming buckthorn and organic white wine vinegar for Merrifield 426 experiment

buckthorn berries boiled in wine vinegar, ready to squeeze out juice (Merrifield 326)
2016 Vinegar and buckthorn:  On October 7, 2016 I tried an even stronger vinegar, Surig Essig-essenz, from an online vendor. It boasts 25% acidity.  I don't know how strong a white vinegar you can make from wine or medieval people would have had access to but using a very strong vinegar and still not achieving green might let me rule out lower acidity as the culprit.

Neither 'strong' vinegars yielded green with buckthorn berries for me.

It now occurs to me that maybe I'm taking the buckthorn and vinegar recipe out of context...?  The recipe before this, 101., and the recipe after it, 103., incorporate verdigris with vinegar and other reagents. (Verdigris in many medieval treatises created frequently by fuming copper with vinegar or ammonia.)  Perhaps it's mistakenly omitted?

Or did everyone just know to always add rock alum to buckthorn to produce green?  Vinegar or not that seems to work...

The paint results of these vinegars with buckthorn berries and also with the modification of added alum (potassium aluminum sulfate) can be seen here.

Later in the same book it talks about using vinegar with buckthorn to dye skins green but putting either of these resulting liquids on leather doesn't seem to produce green either.  Someday I'll get to take pictures of those results and put them here.  Promise! ;)

Bolognese Manuscript De Tintis ad Tingendum Pellem (Merrifield 558)


  1. Adrienne, I saw something similar to this done in a single photo in Panayotova's book Colour; The Art And Science Of Illuminated Manuscripts, only it was on paper. However, the recipe was not well described (common in this book)and I am at a loss as to how they got it without alum or calcium. I considered that they "might" have used a paper which may have been buffered with calcium to offset paper's general acidity (unlikely for a scientist), but that wasn't described either. Anyway, my experience is that you need the buckthorn berries at EXACTLY the right stage of ripeness for good results. That is: Black outside, with very purple juice inside. The timing depends on the bush, the temperatures, and how much sun it gets, but generally early to mid-September here in Ann Arbor Michigan (this year was way later than the past several). All you need to do is crush the juice from the berry mass, filter out the pulp & seeds, and pour it into a dish with some alum water and a bit of alkali. I just powder some rock alum and toss that and the buckthorn fluid into a clam shell and wait several minutes. Works every time. As for the book- There are a lot of ups, and a few downs. They describe a number of MS pages and cite what they found for colors used, but they don't cite all of the colors, and they don't usually specify better than "Red insect dye" for example, and they seem to think Tyrian purple was used on some pages when it probably wasn't, and they spend a lot of time talking about the meaning of the book, which really has nothing to do with the science of the colors. Sigh. But more good things include talking about relative color prices (not comprehensive, and the prices varied from place to place and by economic/political forces, which was not well described), and they talk some about methods (though some methods are disappointingly missing). The book is not available online right now unless you look for it on a free downloads site, but you can find a couple of chapters on the author's page at I recommend getting it this way or reading it from an ILL loan before purchase. The book is actually a collection of essays and lots of photos, written by several authors.

  2. Thanks; it's always great to get your opinions and get extra resources! In Maine buckthorn seems to always have seeds, juice or not, and "early" and "late" fall berries give purple juice to make the green. The more ripe they are in general, the more juice until they start to dry up quite late in the fall. The weird thing about this one was that I never added an alkali. I used a plastic palette, not a clam shell and clam, egg and lye was never introduced. Only buckthorn berries, vinegar (organic white wine and 25% white) and ultimately potassium aluminum sulfate.