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Black-Sope-art - 10/24/17


"To Make Black Sope" by Lady elska á Fjárfella. Arts and Sciences Competition entry.


NOTE: See also the files: Med-Soapmakng-art, soap-msg, Hist-of-Soap-art, Roman-hygiene-msg, Lye-Soap-art, soapmaking-msg, Soapmakng-CMA-art, Frsh-Egg-Test-art.





This article was added to this set of files, called Stefan's Florilegium, with the permission of the author.


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Thank you,

Mark S. Harris...AKA:..Stefan li Rous

stefan at



You can find more work by this author on her blog at:


To Make Black Sope -

16th century soft soap based on

the Secretes of Master Alexis of Piemont

by Girolamo Ruscelli


by Unnr in elska á Fjárfella

Of the Dominion of Myrkfaelinn in the Kingdom of Aethelmearc



For the Passing of the Ice Dragon

A&S Pentathlon



Black soap?


Black soap, or soft soap, gets its name from the dark color of the wood ash lye used to make it (and the cast iron it was often boiled in). Hard soap from southern Europe was made with high quality barilla ashes, which makes a light colored lye (and hard soda soap); therefore white soap quickly equated with high quality hard soap. One of the earliest references to soap manufacture is by the monk Richard of Devizes in about 1200CE: "Apud Bristollum nemo est qui non sit vel fuerit saponarius" (in short: Bristol soap making smells). Black soap was, as shown by many price agreements where it was sold in small pots, or bulk in vats, a soft soap. In 1511 there was controversy among London soap boilers regarding the composition of black soap. In 1624 the Bristol City Council made an ordinance that Bristol soap could only be made from olive oil, with the interests of southern merchants in mind. An earlier a soapmakers' ordinance from 1603 expressly forbade any soapmaker to buy tallow after successful lobbying by the Chandlers and train oil (from marine mammals) was not allowed on penalty of heavy fines! (Matthews 1940)


Clearly, soap making in the late middle ages was a highly regulated Guild business, and not in least because of the difficulty of producing an adequate product. When civil unrest in France forced the Marseille soap boilers to relinquish their occupation, ten years later it took a government sponsored scientific inquiry to regain their expertise to once again create quality soap. (1801) Soap was regarded a luxury item in many western European countries including England and taxed as such, keeping quality soap out of reach of the general public. In 1631 this commodity of soap led to the sale of a monopoly for the making of soap to a company at Westminster, which was a death blow to the Bristol soap industry. (Matthews 1940)


Why this recipe?


After working with several 12th and 13th century medieval soap recipes I came to the conclusion there is lack of information – deliberate or not – which leads to unreliable and low quality soap. The recipes are brief and probably incomplete; likely written by a master for his workshop, not for the uninitiated. Not until the 16th century, when the average person learned to read and a mass market was created for how-to books, a great number of recipe books, how-to manuals and translations of manuscripts that had previously been only accessible to the elite hit the market. These later medieval texts are a great resource for interpretation of earlier medieval recipes, a real blessing and the source of many "aha!" moments!


My goal of working from the Master Piemont recipe was to create a foolproof medieval soft soap recipe using common household equipment that any mundane soap maker can emulate. Even though I own a round bottom cast iron cookpot and have used it successfully to make medieval soft soaps, even outdoors over open fire, here I choose to use a crockpot; cast iron is not something most mundane people have laying around, but most importantly, a crockpot is made to regulate temperature over long periods of time. And technically, our modern crockpot might be more similar to the soap boiling vats used by Guilds than you might expect, as these were especially constructed for soapmaking and highly insulated for an even and constant temperature while heating with wood, something sadly modern society does not have the equipment for anymore.


Summary of the original Recipe and the Process used to create it.



16th century recipe on Lye



Fortify the ashes with quick lime.


Place the fortified ashes in a barrel with a hole at the bottom. Cover the hole with straw and an upside down plate as a filter.


 Press down the ashes well, make a flat top and slowly add hot water. Do not let drip until all ashes are wet. Then let drip very slowly.


Test the lye coming out with an egg; separate the first lye (floats an egg) from the second lye (suspends an egg), third lye (barely sinks an egg) and fourth (pretty much water).


Save all separately and cover well.


21st century technique on Lye


Use woodstove ashes. Grey makes brown lye, high efficiency burned white ashes makes pale yellow lye.


Place the ashes in a bucket with a hole at the bottom. Plug the hole with a piece of cloth to act as filter.


Press down the ashes well, make a flat top and slowly add hot water first, room temperature water (rain barrel) later. Do not let drip until all ashes are wet. Then let drip very slowly.


The lye coming out from grey ashes sinks an egg like third lye and needs to be condensed before use, lye from white ashes floats an egg from the get go.


Use mason jars for airtight storage.



16th century recipe on Soap


Use 3 pounds of egg bearing lye to 1 pound of oil.

Pour the oil into the lye and mix well.

Let stand overnight.


The better the oils are incorporated (stirred) the quicker it will simmer.



Make sure to leave at least a hand's width of space on top so the soap does not foam over.



The next morning simmer the soap until it rises up, then cool down and simmer again.



21st century technique on Soap


Use 3 pounds of egg floating (for sharp laundry soap) or egg suspending (for neutral hand soap) lye to 1 pound of oil.

Mix well, and let stand overnight.


Before heating it stir well.

Check there is enough space above the soap surface so it does not foam over.


The next morning turn the crock on high and close the lid. Stir occasionally and keep a close eye on it.


When it starts to foam, stir well and instead of a completely closed lid, put a toothpick between the edge of the pot and lid (needs heat, but not pressure)

Simmer for about eight hours.


Test the soap, if it is oily add some first lye, if it is sharp add some or oil.



When the soap becomes thick, sticks to the spoon without falling off and stays solid when cooled off, it is a sign it has cooked enough.



And he who has experience knows what to do in one boil.


Simmer for 6-8 hours, stir occasionally.


Test the soap with the tongue, if it 'bites' it is lye heavy and could use some extra oil. Rub it between the fingers, if it feels oily (and does not taste sharp) add some extra lye (this is what the different grades lye are for).


When the soap starts to thicken (trace) take off the lid to let excess moisture evaporate.


When the soap resembles Vaseline; it sticks to the spoon, it parts when stirred and stays solid when cooled off, and then it is done.

Medieval washing bat

Composts et le Kalendrier des bergères, 1499



The original Recipe


To make black Sope for clothes, with all the signes and tokens that it giueth and maketh in beiling.


TAke thirty pounde of vnsleckt white lime, if you can get it, and that is in greate hole peces and not in pouder, and foure skore and tenne pounde of the strongest ashes you can finde.

Then order & dresse the ashes rounde about the lime, in forme and maner of Morter, and sprinkle with a broome weate in water the small peces of lime a little at ones and often, to the intent that the fire maie en|ter into it, and whan it is well mollified and augmen|ted by reason of the heate whiche is in it, let there bee two of you, the one to incorporate well with a spade or shouell the lime with the ashes, and the other to sprinkle water with the broome well vpon it & round about it, to the intent there rise no pouder or dust of it.

And lette all so well be mixed, that a man may not knowe or discerne the lime from the dust or ashes, and water it so much round about, that in taking a hand|full of the same matier, and in wringing it, it cleaue togither. And whan you see that it raiseth no more pouder or dust, giue it no more water.

This done close vp togither all this morter with your spade, and lette it so remaine in a heape twoo or three houres, for it 129 heateth and boileth beyng in a heape, and wha~ it ma|keth chinkes or cleftes about it, it is a signe that it is risen. And if it be in cold weather you maie couer it, for feare that it take no colde and so lo se his heate, for than it would make no good magistrale.

Whan all this is done, straine the said mater in a vessell of earth hauing a hole in the bottome, beyng couerid with a little strawe, and a dishe ouer it, to the intent that the mater maie runne in time: and whan you putte it in presse egally euery where as muche as you can,  and lette it be alwaies euen aboue: then poure vpo~ it some hote water, or els do as followeth, as I my selfe doe.

Make ready sixe or eight pailes full of the strained lie, and poure it on the vessell I meane of the first whiche is good, and at the first put in two or three pailes full, the whiche beyng sunke doune, put in as much more, and open not the hole in the bottome, vntil al the ma|ter be drunke vp: then let it runne out by little & little, and bicause you maie the better knowe the firste, the seconde and the third, take an Egge newe laide, and binde it rounde about with a threede and as the ma|gistrale lie commeth out, put the Egge into it, and whiles the egge remaineth aboue, put it al into a ves|sell, for it is the first whiche you ought to make muche of.

And whan the egge sinketh in the lie, put that se|cond by it selfe: and if you can gette of the first fo[...]rty pounde, you shall get of the seconde thirtie, and of the thirde twentie, and of the fourth asmuch as you will: And let all these be put by them selues: & if you couer them well that they do not euaporate nor breath out, they will continue alwaies a yeare beyng still good, whan you haue done take xxx. pound of the first, and ten of the seco~d, and put them togither and looke well if the egge remaine aboue, & if it appeare not muche, weaken it no more, for it shalbe wel so.

And note, that vnto three pound of the saide lie, you muste haue one pound of oile, and in pouring it in sturre and mixe it 130 well with a stick, for feare that the oile be not hurt by the violence of the saide lie: And make this composi|tion at night, to the intent that it maie remaine in in|fusion all the night: then in the morning seeth it the space of seuen or eight houres or more, according as the quantite is great or little: for whan it is aboue a hundreth pound, it must seeth ten houres or more: and whan it beginneth to seeth and swell much, take it by and by from the fire, and sturre it alwaies aboue vn|till it beginne to boile softly.

And in the meane time cease not to sturre it, for feare it burne to the bottom. And whan you make the composition in a caudron, let it neuer be full by a hand breadth, bicause it riseth and swelleth alwaies in seething, and the oile would bee loste: and mixyng it oftentimes the oile incor|porateth with the lie, and seedeth the sooner.

And whan it hath sodden about eight or nine houres, you maie beginne to assaie and proue it, and see that you keepe alwaies a little of the firste and of the seconde for all occasitions that maie chaunce. And whan it hath boiled vnto the saide houre, you shall see it waxe thicke, and make the bubbles in seething long and thicke. Than maie you beginne to make your profe and assaie.

That is to saie, in taking a little of it with a spoone, and putting it into a little earthen dishe, and lette it coole, then cut it with a little sticke, and if it close togither againe, it is a signe that it is sodden inough: and if it doe not close togither againe, it is not, and therefore finishe the seething of it. And make many of these proofes and assaies.

And whan it is sod|den, take the fire from vnder it, and so take it of, and sette it in some coole place, and whan it is colde you maie occupie of it, and it will be good and parfite. And if you make it with cleere oile although it bee strong, it is all one: but if you make it with oile parcht or thicke, it will not bee verie cleere.

One of the beste signes that you maie see in it whan it beginneth to 131 waxe into a thicke substance, is that in taking of it vp with a spoone, the thredes or little strekes doe breake without shrinking vp again, & this is a signe that it is sodden inough.

And whan you haue taken vp a lit|tel, and haue lette it coole and so cut it, and than if it be ferme and faste on the sides, and in setting it vp it tarry vpright, than it is sodden. And if after an houre it were not sodden, that is to saie, that it had not the sinewe, put vpo~ it a little of the first magistrall a little at ones, and so lette it boile an houre or a halfe.

And than you shall make againe the like assay or proofe as before, and if it shewe you not good signes, you shall put yet a little more to it vntil you make it haue a fast and solide bodie, & let it be not to soft nor to hard. And he that hath experience of this knoweth what is to be done in seeyng it boile onely. And whan you see that it is well take it from the fire.


Unedited, except for the addition of paragraphs for ease of reading.



Transcription of the original recipe.


To make lye (summarized):


Use unslaked lime [quick lime] in pieces, not powder, and the strongest ashes [hardwood] you can find. Pile the lime up and heap the ashes around the lime, like making mortar, and with a rush broom, gently sprinkle water all over it so the lime will activate. Work it with two people, one with a shovel to incorporate the lime with the ashes, and one with the rush broom to sprinkle water all over, until there is no more powder and the lime/ash mixture is indistinguishable from each other and sticks together when squeezed.


Leave the heap for 2 to 3 hours for the exothermic reaction to work itself out, and when the heap starts to crevice and crack, it's ready. If the weather is cold you may cover it so it does not loose the heat and slow or stop the reaction, for then it is no good.


Then put the lime/ash in a barrel with a hole in [at] the bottom, covered with a little straw and a dish over it to slow down the leach. When filling, press down equally as much as you can, make a flat top and pour in some hot water. At first put in two or three pails and as it settles more, and do not open de hole at the bottom until the lime/ashes are all wet: then let it run out little by little.


To know the difference between first, second and third lye, take a fresh egg wound around with a thread [to be able to take it back out] and as the first lye comes out float the egg on it. Save this lye for as long as it floats as this is the best lye.


When the egg starts to sink, save this separately as the second lye, you should be able to get 4 parts first lye [floating, with a quarter of the shell showing], three parts second lye [hovering in the middle of the jar], 2 parts third lye [touching bottom but still upright] and as much fourth lye as you want [when the egg settles flat on the bottom the density of water is reached]. Save all these separately and cover them well so that they do not evaporate or breath out [lye is hygroscopic and will pull moisture from the air] and they should be fine for about a year.


To make soap:


Use 3 pounds of egg bearing lye to 1 pound of oil, pour the oil in and stir and mix well. Do this in the evening so that the infusion can stand overnight. In the morning start to simmer it, for seven to eight hours; if it is over 100 pounds simmer ten hours or more.


When it starts to simmer and rise up a lot, take it from the fire and stir it well until it starts to go down again. Keep stirring so it does not get burned to the bottom. When you use a cauldron leave a hand width of space because the soap rises and swells in cooking and oil would be lost. The more it is stirred and the oils incorporate well with the lye, the sooner it simmers.


When it has simmered for about eight or nine hours it is time to take samples and check. Make sure to have some first and second lye ready as needed. When it has boiled until the right time you shall see it become thick, and make long and thick bubbles when simmering.

To take a sample, take a little with a spoon and put it on a small earthenware dish and let it cool. Then cut it with a little stick and if it closes again it is a sign it has cooked enough; if it does not close, it is not finished, so keep simmering it [is this reversed?]. Take many samples and check.


When it is cooked, take it off the fire and set it in a cool place, and when it is cold you can start using it, and it will be good and perfect. One of the best signs that you may see is that when it begins to thicken, pull some up with a spoon – when the stretchy threads break without shrinking back up again, this is a sign it has cooked enough.


And when you take a little, and let it cool and cut it, and it is firm and solid at the edges, and it stays upright, then it is cooked enough. And if it was not cooked enough, if it did not have the stretchy threads, add a little of the first lye, a little bit at a time, and let it boil for an hour, or a half.


Then test again, and if it is still not good, add a little more, until it has a firm and solid body, but not too soft or too hard. And he who has experience knows what to do in one boil.


Strength of lye?


The main recipe mentions lye strong enough to float an egg: "the magistrale lie commeth out, put the Egge into it, and whiles the egge remaineth aboue, put it al into a vessell, for it is the first whiche you ought to make muche of". This is also the strength mentioned in many Colonial recipes for making drip ash lye, and the soap that reenacters complain of as being so harsh. This is Laundry Soap or Black Soap and is meant to be harsh to better to clean cloths with. It is also harsh on the washed fabrics resulting in wear and tear and if the garments are not rinsed well soap remnants in the clothes are known to itch… good reasons why wealthy households would buy their soap and not make it themselves (difference between just harsh enough and too harsh). This does not mean all soft soap is harsh, only that laundry soap recipes make harsher soaps.


An example from the first book of The secretes of the reuerende Maister Alexis of Piemount Containyng excellent remedies against diuers diseases by Girolamo Ruscelli shows the following recipe for shampoo. It lists the strength of the lye "as stronge lye that will beare an egge swimminge betwene two waters" which I interpret to mean suspended in the middle. As suspended-egg lye makes neutral soap which does not 'bite', this makes complete sense as this is a soap meant for personal use. It also uses the amounts of thre pottels of lye to one pot of oyl, the 3:1 ratio that consistently works well for me.


A very exquisyte sope, made of diuers thinges.

TAke Aluminis catini thre vnces, quicke lyme one part stronge lye that will beare an egge swimminge be|twene two waters, thre pottels, a pot of commun oyle: mengle all well together, puttinge to it the white of an Egge well beaten, and a dysshefull of the meale or floure of Amylum, and an vnce of Romayne Vitrioll, 55 or redde leade well beaten into poulder, and mixe it continuallye for the space of three houres, then lette it stande, by the space of a daye, and it will bee righte and perfite. Finallye,  take it oute, and cutte it in pieces: af|ter sette it to drie twoo daies, in the wynde, but not in the sunne. Occupie alwaies of this sope, when you will washe youre head, for it is verie holsome, and maketh faier heare. (Ruscelli 1558)
How to make soft soap, the Medieval way.


A step by step modern how to manual.


Fill a 5 gallon bucket with filtered ashes, tamping down intermittently for a tight fit. Level the top leaving about 2 inches of headroom. Slowly pour rain water on top, enough for about a layer of an inch on top. Let it sink in. When gone, add another inch layer and let it sink in. It should take about a day of slowly adding water until it starts to drip out at the hole at the bottom. If your bucket goes faster tamp the ashes down better next time, and plug it up for about a day. When the drip starts regularly add a layer of water for a slow drip, drip. Collect the drip lye and when there is about a gallon test the strength.


For grey ashes the lye will be dark brown and will not float an egg. Heat the lye and evaporate until it has the desired strength (likely to about a quarter of its volume). Cool down before use, real hot lye added to oils can scald the soap but also this way, superfluous salts will settle out of solution and a more pure lye water can be poured off the next day. Discard the sediment.


For white ashes the lye will be pee colored and will float an egg from the get go. For sharp laundry soap use as is, for neutral hand soap slowly add some water (small amounts!) until it suspends an egg in the middle of the jar (use a clear jar so you can see, like a mason jar).


Measure out 1 pound (16 oz) of oil and 3 pounds (48 oz) of lye. Add the lye to the oil; with liquid-by-room-temperature oils the lye and oil are added at room temperature; with tallow and lard, the lye is added when barely melted. Mix very well (stick blender helps) and let sit overnight.


The next day again mix very well as the solution will have separated overnight and then turn on the crockpot on high and close the lid. In about an hour, or two, with an occasional stir but not often as the soap needs the heat, the soap will start to rise and you will se beautiful soap foam forming under the lid. When that happens, open the lid, stir the soap well to cool it down and settle (if you leave it will foam right out of the crockpot). Return the lid but this time with a toothpick in between to create a little gap to let hot air escape. This way the soap can not foam over anymore.


Let the soap cook and cook and cook (at a simmer, never a boil) and you will see bubbles happen at the edge of the ceramic insert. This is the soap turning itself. It should never bubble from boiling (too hot), only at the edges from turning itself (as soap is an exothermic reaction). Finished soap will start forming on top, which is kind of cool. Stir occasionally to make sure no dried out spots happen at the edge of the wall, but be aware, stir gently, as it will suddenly foam right up.


The soap will get thicker and thicker and when it incorporates, or finishes, open and remove the lid so excess moisture can evaporate. The soap will look like custard (trace), leave droplet marks on the surface when scooped (or trace marks) and will drip off a spoon with globs. It is not done yet but you're getting close.


Keep cooking until it starts to resemble Vaseline, it has little wavy heads when stirred and gets a kind of glazed, sleek look. It will stick to the spoon when stirred and not drop off and it will part at the bottom when stirred and lay there piled up and not come back together. For thin soft soap stop here, or keep evaporating moisture until it is as thick as you want. I go for the whipped cream Vaseline consistency.


I have made half a dozen soaps using this technique and each one comes out the same in about the same time span. When emulating this process but in a pot over an open heat source, keep the heat hot but without boiling and keep a lid on the pot – the soap needs all around heat to fully finish is my experience.




If the soap is cooled down and it separated some liquid at the bottom, cook it some more to evaporate excess moisture – you might have stopped too soon at the trace stage.


If the soap is cooled down and creates liquid on top of the soap while uncovered it is probably lye heavy – the excess lye is pulling moisture out of the air. Not necessarily a bad thing; it makes for a wonderful antibacterial soap for instance, or an effective (but aggressive) laundry soap. But if not desired, cook again with a little extra oil.


If the soap separates halfway during the process and just won't come back together again no matter how much you cook, there are excess salts present that are interfering with the process (this is why evaporating and removing sediment with brown lye is important). Either play around with second and third lyes and hope for the best, or clarify your lye for next time.




It is well within our means to make successful medieval soft soaps of both laundry and personal use quality. After many months of trial and error and many mornings at the Cornell Library spent digging through old manuscripts looking for that one recipe that actually made sense, I finally can say: Anyone Can Cook Medieval Soap!


 The two versions I made are both for hand use, and you are more than welcome to try them out.


Of course, the best way to assess the quality of these soaps, and the medieval technique of choice, is to take a small bit on your finger and touch it with the tip of your tongue – if it does not bite like a 5V battery you know for sure I made a quality product.


For the adventurous: dip a taste of the soap and then a taste of the brown lye (NOT the pale yellow) – the second one is how harsh soap would feel like!
Photo Essay



Dripping lye (brown). Making the Lye solution (white). Mixing lye and oil to infuse overnight.



Bubbles start to happen… and we have lift off!



Forming of the skin (the soap is turning from outside in; it looks like tectonic plates).



The soap starting to come together, first as custard, then pudding, and finally –Vaseline!



Same thing, now with light colored lye soap:



Well stirred and heating up. Soap curds are forming on top (it also ate the bamboo skewer).



The soap is starting to turn, a few more hours and – voila! The soap has finished.




(1801) The Repertory of Arts and Manufactures: consisting of original communications, specifications of patent inventions and selections of useful papers from the transactions of the Philosophical Societies of all nations. Vol. XIV Chapter XLII "Of the Manufacture of Soap" London. p. 266-344


Matthews, Harold Evan (1940) Proceedings, Minutes and Enrolments of the Company of Soapmakers 1562 – 1642, Bristol Record Society, Great Britain


Ruscelli, Girolamo (1558) The secretes of the reuerende Maister Alexis of Piemount Containyng excellent remedies against diuers diseases, woundes, and other accidents, with the manner to make distillations, parfumes, confitures, diynges, colours, fusions and meltynges. Translated out of Frenche into Englishe, by Wyllyam Warde.


Ruscelli, Girolamo (1560) The seconde part of the Secretes of Master Alexis of Piemont by hym collected out of diuers excellent authours, and newly translated out of Frenche into Englishe, with a generall table, of all the matters conteined in the saied boke. Transl. William Warde.

Both transcribed by author of this paper; complete texts are available at Early English Books Online (EEBO) at (retrieved 3/2016)



Medieval washing bat (Pá para lavar roupa) from Composts et le Kalendrier des Bergères, 1499 (retrieved 3/2016)


All photograpy by Author of this Paper.



Books that helped understand the process:

Bramson A S (1975) Soap, Making it, Enjoying it Workman Publishing Company

            The little book that sparked a hand made soap revolution, great digressions chapter.


Dunn K M (2003) Caveman Chemistry Universal Publishers

            Geared towards beginner chemists, each chapter explores a project in detail.


Lewkowitsch J (1907) Modern Views on the Constitution of Soap Journal of the Society of Chemical Industry, New York. p. 590-593

Invaluable information on how potash soap would be made on commercial scale, explaining the chemistry, and visuals, each step of the way.


Tunis E (1999) Colonial Craftsmen and the beginnings of American Industry John Hopkins University Press, Baltimore MD. p. 118-119

            A good explanation of how potash lye was leached in Colonial times.


Wigginton, E. (1972) The Foxfire Book Anchor Books, p. 151-158

            The only modern drip lye soap making experience in print, as told by Appalachian folk.


Copyright 2016 by Susan Verberg. <susanverberg at>. Permission is granted for republication in SCA-related publications, provided the author is credited.  Addresses change, but a reasonable attempt should be made to ensure that the author is notified of the publication and if possible receives a copy.


If this article is reprinted in a publication, please place a notice in the publication that you found this article in the Florilegium. I would also appreciate an email to myself, so that I can track which articles are being reprinted. Thanks. -Stefan.


<the end>

Formatting copyright © Mark S. Harris (THLord Stefan li Rous).
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