Modern & Medieval Soap Making Compared.

Have you ever daydreamed about making historic soap all the way from start to finish? I did, and after years of making modern soap I finally took the plunge… and what an interesting adventure it became! Digging through old articles and manuscripts, learning to decipher medieval English, a kitchen invaded by weird concoctions bubbling away – how could something seemingly so simple turn out to be so challenging? I found one of the first hurdles I came to in my quest of making medieval soap was technique: as a modern soap maker working with purified lye my modern experiences and techniques did not quite transfer to medieval recipes using wood ash lye…

First things first. To undertake soap making one should be familiar with what soap is and why it works the way it does. In short, soap is a simple molecule with the unusual ability to dissolve fats and oils into water, making it possible to rinse them away. It is made by mixing dissolved hydroxide salts with fatty acids, resulting in fat salts or soap (for instance, tallow mixed with sodium hydroxide becomes sodium tallowate, or tallow soap). This process is called saponification, from the Latin word sapo for soap. And if you are an outdoor enthusiast you might have inadvertently made soap already. Scrubbing a greasy frying pan with campfire ashes does not just scour the dirt away; rinse with a little water and the hydroxide salts in the ashes will combine with the cooking grease into a primitive cleanser – a way of cleaning dishes and laundry that has been with us through Ancient times!

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 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. Why is this important? It’s because sodium hydroxide made from marine and marsh plants makes solid bar soaps, while potassium hydroxide from land based plants makes liquid or soft soaps. Sodium hydroxide is a small molecule with short and tight molecular bonds which creates soap with a strong crystalline structure. Potassium hydroxide is a large molecule, with long weaker molecular bonds, which creates soap with a weak crystalline structure. It’s the lye that makes the soap.

The first mention of soap being used on a human body for cleaning was in the 4th C: French soap was described by Theodorus Priscianus as a material for washing the head. (Dunn, 233) By the 7th C Italian soap makers were organized into craft guilds and the profession of soap maker is mentioned in Charlemagne’s Capitulare de Villis of 805 AD. By the 8th C, soft soap made with oils was common in France, Italy, and Spain, as olive oil was widely available. It is generally accepted that soap was known in England by the 10th C, most likely introduced by the Celts. (Bramson, 57) Another early reference to soap manufacture is by the monk Richard of Devizes in about 1200CE: “Apud Bristollum nemo est qui non sit vel fuerit saponarius” (about the number of soap makers in Bristol and the smelly nature of their profession). (Matthews, 4) Also by the 12th C, hard soap came into use which was said to be an Arab development later imported into Europe. By the 13th C, the manufacturing of soap in the Islamic world became virtually industrialized, with sources in Nablus, Fes, Damascus, and Aleppo. Around the 13th C, Marseilles emerged as the first great center of European soap making and remained so throughout the Middle Ages. (Bramson, 59) Genoa, Venice, and Bari in Italy and Castile in Spain also became epicenters of soap making due to their natural resources. (Bramson, 57) All had abundant supplies of olive oil and barilla, (Bramson, 57) a sodium rich plant whose ashes were used to make soda lye, a perfect combination to make a beautiful hard white bar of soap.

Since hard soap can be shredded and reformed soap balls came into being, a luxury product used by the upper classes. In Tudor times botanicals were introduced into soap, and scented soap became a "must-have" item of the elite. Fine soaps were produced in Europe from the 16th century on, and many of these soaps are still produced, both industrially and by small-scale artisans. Castile soap is a popular example of the vegetable-only soaps evolved from the oldest “white soap” of Italy.

[SIDENOTE: As soap was considered a luxury, English soap manufacturers had to pay a heavy tax on all the soap they made. Because of this heavy tax, soap was very expensive, sometimes even cost prohibitive to make, and did not come into common use in England until after the tax was repealed in 1852! (Bramson, 59)]


THE DIFFERENT SOAP MAKING TECHNIQUES

MELT AND POUR SOAP
In modern times, this soap is not made from scratch but is bought in a store ready to use and is formulated to melt and reconstitute with minimal issues. As the soap is already processed, it needs no curing time. It comes in two versions, melt and pour soap and melt and pour glycerin. Glycerin soap is the see through soap which is moisturizing and fun to suspend objects in, like pretty botanicals (and toys) as you can see them floating about.

Historically, soap could be bought plain at the Apothecary and used as an ingredient in medicines. Especially prevalent in 16th C medicinal manuscripts, soap used as an ingredient in recipes was well practiced, either for its medicinal benefits or for its easy carrier function.

Medieval examples of re-cooked and dissolved soap recipes:

For the black jaundice.
Take genciana [gentian], long peper [Piper longum], calamus aromaticus [sweet sedge], auencis [unknown], lycores [liqueur], raisins of currants [dried currants], white soap of Spain, of every  i. 3. and two spoonfuls of mustard, and boil all these in a quart of wine until a third is evaporated, and let the patient drink it.
This is the glasse of helth. by Thomas Moulton, 1547.

An excellent soap for scabies and itch.
Take white soap half a di. and steep in sufficient rose water, until it is well soaked, then take two dragmes of mercury sublimed [mercuric chloride], dissolve it in a little rosewater, mix the soap and the rosewater well together, and afterwards add a little musk or civet, and keep it. This is the best to cure a great scabies or itch without harm.
A short discours of the excellent doctour and knight by Leonardo Fioravanti, 1588.

And if you are indisposed to break the skin, and let your humours [blood] out (as by such manner one is eased), you shall make a little plaster of black soap and aqua vite [grain alcohol], which will blister it without any great pain.
The regiment of life by Jean Goeurot, 1550.


TRANSLUCENT SOAP
By cooking a basic soap with granulated sugar and alcohol it is possible to create a translucent soap (this is not glycerin soap, but glycerin can be added as a moisturizer). I have not found any historic recipe using a similar technique or ingredients.


HAND MILLED & GRATED SOAP
A modern way of making several kinds of soaps without making a batch of each is to make one large batch of base soap, grate that down, and use as needed. The grated soap is melted au-bain-marie in a 1:2 water to soap mixture. Heat the water to 180 degrees and add the grated soap. When soap and water have blended and the mixture turns clear, herbs, spices and essential oils can be added. Be aware certain essential and fragrance oils do not deal well with heat and can evaporate, so check to make sure your choice of essential or fragrance oil works with a hand milled soap. Hand milled soaps and rebatched soaps are similar as both are grated and reheated with water, except in the case of rebatched soap only a little water is added. This technique is often used to save cold-process soaps that went wrong and need to be re-cooked.

Commercial soap is also milled, but by machines that press freshly made soap between sets of rollers to flatten it paper thin. It gets shredded, and the soap flakes are ground through the rollers again and again, squeezing and mixing them together. Then it goes through an extrusion machine to squeeze out a long bar of tightly compacted soap flakes, that gets cut into individual bars.
   
By the Renaissance, soap could be bought premade and used as an ingredient in medicines, laundry and toiletry soaps. Especially in Tudor England hard white soap would be used grated to make specially scented and herbed soap balls or wash balls.

[SIDENOTE: Despite the general modern believe that people back then did not bathe much at all, the Tudors did keep themselves clean –by continuously changing and laundering their underclothes and by sponge bathing. Henry VIII and other royals had permanent plumbed-in bathrooms, like those built at Hampton Court and Whitehall. Of course, these magnificent bathrooms were great luxuries. As Tudor style clothes were tight fitting and often of not easy to clean fabrics an interest in personal cleanliness developed around that time – as shown by various toiletry soaps (and stain removal recipes) that began to show up in various household instruction manuals (livinghistory)]

Sir Hugh Plat, in his Delightes for Ladies to adorne their Persons, Tables, Closets, and Distillatories with Beauties, Banquets, Perfumes & Water, shares a great recipe for 'a delicate washing bal’:

Take three ounces of Orace [orris, or Iris rhizome], half an ounce of Cypres [Arum or jack in the pulpit], two ounces of Calamus Aromaticus [sweet sedge], one ounce of Rose leaves, two ounces of Lavender flowers: beat all these together in a mortar, push them through a fine sieve, then scrape some Castile sope, and dissolve it with some rosewater, then incorporate all your powders together, by working them over well in a mortar.
Delightes for Ladies (1609) by Sir Hugh Plat

Another nice on how to make ‘White musked Soap’:

Take soap scraped or grated, as much as you need the which (when you have well steeped and tempered in rose water) leave it eight days in the sun: Then you shall add to it an ounce of the water or milk of Macaleb [Prumus maheleb], twelve grains of musk, and six grains of civet, and reduce all together into the form and manner of a hard paste, you shall make of this very excellent balls.
The secretes of the reuerende Maister Alexis of Piemount (1558) by Girolamo Ruscelli

Making soap balls is easy, as all one needs to do is grate soap into slivers (by hand or with a kitchen machine), add a tiny bit of water or milk to make the slivers sticky, kneed a bit by hand and then roll the sticky mass into a ball. Dry for a few days and the soap is ready to be used. Plain olive oil based soap like Castile Soap most similar to medieval white soap.


LIQUID SOAP
Modern liquid soap can be made by dissolving sodium hydroxide soap into water, which it does not like to do naturally, or by making soap with potassium hydroxide. Modern potassium hydroxide soaps are similar to medieval soft soap, as potash lye is the natural form of potassium hydroxide; with contaminants and of uncertain strength.

Caustic potash, the natural source of potassium hydroxide, was generally available because of wood heating and cooking. By leaching caustic ash with soft water (predominantly rain water) lye or hydroxide was formed. This lye solution would be weak compared to modern lye, at about pH11, and would have many other minerals in solution; like sulfites, chlorides and carbonates - most of which are of no use and can even detrimental to the saponification process. Weak drip lye could be evaporated to concentrate its strength, which also helped to remove unwanted salts as most would settle out of suspension and the still dissolved lye could be poured right off. Drip lye could also be fortified by calcining the ashes with lime, thereby oxidizing ash carbonates into hydroxides and raising the pH of the lye.

[SIDENOTE: Black soap was, as shown by many price agreements where it was sold in small pots, or bulk in vats, a soft soap.  (Matthews, 4) 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. (Matthews, 4) 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, 5)]

From the Mappae Clavicula comes the following soap recipe using wood ash lye. This recipe uses the word “clarified” in connection with evaporated lye, which I interpret to mean the lye was decanted off its sediments. Especially in older recipes from Guild sources information can be presented incomplete or out of order, in this case mentioning heat after clarification, but since later period recipes confirm the process this interpretation makes the most sense.

280. How soap is made from olive oil or tallow
Spread well burnt ashes from good logs over woven wickerwork made of withies, or on a thin-meshed strong sieve, and gently pour hot water on them so that it goes through drop by drop. Collect the lye in a clean pot underneath and strain it two or three times through the same ashes, so that the lye becomes strong and colored. This is the first lye of the soapmaker. After it has clarified well let it cook, and when it has boiled for a long time and has begun to thicken, add enough oil and stir very well. Now, if you want to make the lye with lime, put a little good lime in it, but if you want it to be without lime, let the above-mentioned lye boil by itself until it is cooked down and reduced to thickness. Afterwards, allow to cool in a suitable place whatever has remained there of the lye or the watery stuff. This clarification is called the second lye of the soapmaker. Afterwards, work [the soap] with a little spade for 2, 3 or 4 days, so that it coagulates well and is de-watered, and lay it aside for use. If you want to make [your soap] out of tallow the process will be the same, though instead of oil put in well-beaten beef tallow and add a little wheat flour according to your judgment, and let them cook to thickness, as was said above.
Mappae Clavicula; A Little Key to the World of Medieval Techniques, 12th C.


The following recipe from the Secretes of Alexis of Piemont mentions the correct proportions of lye to oil for a successful soap boil “vnto three pound of the saide lie, you muste haue one pound of oile” and also stresses not to boil but to simmer the soap; for a long, long time.

To make black Sope for clothes, with all the signes and tokens that it giueth and maketh in beiling.
[…]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 [this is reversed]. Take many samples and check. [..]
The seconde part of the Secretes of Master Alexis of Piemont by Girolamo Ruscelli, 1560.


[SIDENOTE: Soap was regarded as 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 a million pounds for the making of soap by the Crown to a company at Westminster, which was a death blow to the Bristol soap industry. (Matthews, 3)]


HARD SOAP
Modern hard soap is made with sodium hydroxide lye which is easily available in pure crystal form. It was not until pure crystallized sodium hydroxide was invented and patented by French chemist Nicolas Leblanc in 1790 that exact measured recipes with predictable results were possible, and in combination with advertisements, the soap industry became what it is today.

Historically, sodium lye was made by leaching sodium rich ashes, made from burning marine or marsh plants. Coastal regions with access to these plants, especially Barilla which is known for sequestering sodium chloride in unusual high amount, had access to sodium rich lye and could therefore make hard white soaps. For instance Savon de Marseille and Aleppo soap are well known modern soaps based on century old techniques, with Nabulsi soap tracing its roots all the way to the 10th century.

Liquid soap worked well for cleaning and laundry but dilutes quickly and thus wastes more than hard soap; hard soap was prized for its economy but because of the lower availability of sodium hydroxide much more expensive. One way around this was quickly discovered, and by salting out potassium hydroxide soaps during the cooking process with sodium chloride, or ordinary table salt, an amazing chemical exchange happened. The potassium switches places with the sodium and sodium hydroxide is formed, thereby creating hard sodium hydroxide soap out of soft potassium hydroxide soap!

As the coastal plant barilla is hard to come by, making historic white soap is challenging. One way around this is to burn kelp to ashes, which is available in 50# bags at your local feed store. Kelp is a marine plant and produces sodium lye, but as it does not sequester salt the way barilla does, a lot more kelp is needed compared to barilla. A more modern technique would be to mix calcium oxide (pickling lime) with sodium bicarbonate (baking soda), with the carbonates standing in for the burned plant materials. By adding water sodium hydroxide is formed and can be used to make hard soap with. While this technique mimics the natural ingredients, it does not fully emulate the process as the ashes from burned plants would have other trace minerals and salts.

The Al-mukhtara` fi funun min al- suna` (Inventions from the Various Industrial Arts) by King al-Muzaffar Yusuf ibn `Umar ibn `Ali ibn Rasul of the 13^th century includes a Description of Soap Making. Even though the source of the alkali (al-kily) is not disclosed this is clearly a recipe to make hard soap as at the end it states: The purpose of the mold is to prevent the soap from flowing until it thickens. Leave it for one night and one day until it solidifies. Then cut it with a knife as is usual.

A different type of hard soap is made by adding table salt to a soft soap to salt out and transform it into a hard soap.

When you want to make white soap, use the same materials and techniques and when it is more than halfway cooked, put in some salt, according to the consistency and quantity of it [the soap], and let it boil a little: then take it out of the cauldron, & put it in another & when it begins to boil add more salt and let it simmer to its perfect consistency. To make similar [soap] with Soda, as they use [do] in Venice, the salt must be crushed, and ten pound of it for the hundred [pounds of soap] and mix it all about and put it in a little at a time.
The seconde part of the Secretes of Master Alexis of Piemont by Girolamo Ruscelli, 1560.


COLD PROCESS SOAP
This is the most common soap technique used by soapers worldwide. It uses minimal heat and needs a couple of weeks for the lye to work through its chemical reaction, resulting in about 4 weeks of curing time. The trick with cold process is to have the temperature of the fat/oil mixture and the temperature of the lye/water mixture just right: around 100 degrees F for oils or about 120 degrees F for fats, combined with about 100 degrees F for the lye water. Fat mixtures are heated a little higher as they can solidify at around the target temperatures resulting in false trace.

Due to the fact that cold process soap can only reliably, and safely, be made with accurately measured ingredients, it was not until density was understood that medieval cold process soap recipes start to appear. In the mid 1600’s the egg float test is discovered to test the density of a solution, and as a fresh egg is about the same density as lye, if it is floating with about a quarter of its shell showing, the amount of alkaline salts in solution is of the correct density for laundry soap (also appeared around the same time to check the amount of sugars in solution for fermentation).

The following recipe from the Secretes of Alexis of Piemont (1560) mentions the correct strength of lye used to make laundry soap: “…put the Egge into it, and whiles the egge remaineth aboue…” or a floating egg.
To make black Sope for clothes, with all the signes and tokens that it giueth and maketh in beiling. […] 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. […]
From The seconde part of the Secretes of Master Alexis of Piemont by Girolamo Ruscelli, 1560.

Many Colonial recipes for making drip ash lye also mention to use lye that floats an egg (with a quarter of its shell showing) and this is the soap re-enactors complain of as being so harsh. This is Black Soap, or laundry soap and meant to be harsh to better to clean clothes 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.

The following medieval cold process recipe on how to make a shampoo, uses a different strength of lye which I found from personal experimentation to be neutral. It mentions “… that will beare an egge swimminge be|twene two waters…” or, the egg is not floating on top, but suspended in the middle. Suspended-egg lye makes near-neutral soap that does not ‘bite’, which makes complete sense as this is a soap meant for personal use. This recipe also confirms the amounts of “thre pottels of lye to a pot of common oyl”; the 3:1 ratio which consistently works well for me. 

A very exquisite soap, made of many things.
Take Aluminis catini [unknown] three ounces, quick lime one part, strong lye that will suspend an egg in the middle, three pottels, a pot of common oil: mingle all well together, add the white of an egg well beaten, and a dishful of meal or flour of Amylum [wheat starch], and an ounce of Romayne Vitrioll [cupric sulphate], or red lead [lead oxide] well beaten into powder, and mix it continually for three hours, then let is stand, for a day, and it will be right and perfect. Finally, take it out, and cut it into pieces: after set it to dry two days, in the wind, but not in the sun. Always use this soap when you wash your head, for it is very wholesome, and makes fair hair.
From The secretes of the reuerende Maister Alexis of Piemount by Girolamo Ruscelli, 1558.


HOT PROCESS SOAP
The modern technique is called hot-process because the saponification process is accelerated with heat. The soap is made similar to cold-process soap, using oil/fats, lye and water. The ingredients are brought to trace, but then the soap is exposed to heat and "cooked" through the saponification process. At the end fragrance and color are added and the soap is poured into a mold. The hot process somewhat changes the appearance of the finished soap from cold-process, but allows the soap to be fully saponified and immediately ready for use within just a few days. It has the same basic function as cold process soaps, but generally a less dense and more "fluffy" appearance and texture, similar to rebatched soaps.

Contrary to what most soap makers assume, this is the technique most commonly used for historic soap making as it is not mandatory to have the exact measurements of lye and fats used to create successful soap. It is possible to add more lye or more fats during the cooking process, to remove or change excess or spent lye water and to remove already formed soap. Historic commercial soap vats would have a drain at the bottom to facilitate draining of spent lye, and this “second lye of the soapmaker”, which was rich in glycerin, would be sold to other artisans. This is also the process used for modern commercial soap making as it is this process that gives the opportunity to separate and remove glycerin from the soap in process (and why artisan made cold-process soap is so much nicer for your skin).


Two examples of Medieval cooked soap:

280. How soap is made from olive oil or tallow
Spread well burnt ashes from good logs over woven wickerwork made of withies, or on a thin-meshed strong sieve, and gently pour hot water on them so that it goes through drop by drop. Collect the lye in a clean pot underneath and strain it two or three times through the same ashes, so that the lye becomes strong and colored. This is the first lye of the soapmaker. After it has clarified well let it cook, and when it has boiled for a long time and has begun to thicken, add enough oil and stir very well. Now, if you want to make the lye with lime, put a little good lime in it, but if you want it to be without lime, let the above-mentioned lye boil by itself until it is cooked down and reduced to thickness. Afterwards, allow to cool in a suitable place whatever has remained there of the lye or the watery stuff. This clarification is called the second lye of the soapmaker. Afterwards, work [the soap] with a little spade for 2, 3 or 4 days, so that it coagulates well and is de-watered, and lay it aside for use. If you want to make [your soap] out of tallow the process will be the same, though instead of oil put in well-beaten beef tallow and add a little wheat flour according to your judgment, and let them cook to thickness, as was said above.
From Mappae Clavicula; A Little Key to the World of Medieval Techniques, 12th C


[1.26.1] On Making Soap XXVI: Take a measure of common oil, and two quarters of capitellum [i.e. potash lye, see 1.26.2] and leave it to boil in some vessel on a slow fire until it arrives at thickness, which you test by putting a drop on marble, if it will have held itself together in shape it is good – and once again  [i.e. as one did for gum] you may know [which capitellum is best] by the taste on the tongue: that which clearly gives a sharp taste – and do this three times, in the same way put in [more capitellum] but that which has less sharp taste following the first, and, lo and behold, Saracen soap.
From Liber diversarum arcium (Book of Various Arts), ca. 1300


CONCLUSION

To summarize, soap has been known and used throughout recorded history but the widespread use of soap as we do now is relatively new. Soap was considered a luxury; it was hard to make and expensive to buy, and would mostly be used where it was needed: an ingredient in medicines, or to clean laundry and household goods. As most of medieval Europe was Christian and Christianity did not place much interest in personal hygiene (it is one of the few religions where personal hygiene is not minutely dictated), cleanliness was up to regional cultures, superstitions and whatever belief medical society would subscribe to. (Ashenburg, 11) Not only were dirty old hermits seen as religiously pure – drawing a connection between dirty of body and pure of mind, but with physicians believing bad vapors were behind most ailments and that a clean body would open the pores to let them in, bathing soon became something to avoid. So for most of medieval Europe soap and water were for cleaning clothes, while people cleaned themselves by changing their under linens and using fragrances to cover up, as much as was possible, any body odors. (Ashenburg, 11)

In medieval times, a chemist was an alchemist – and crafts based in chemistry, like glass making, ceramics, brewing, and soap making were not understood on a modern chemical level. They were learned by trial and error, by years – generations – of practice, and the close kept secrets were passed on from father to son, from master to apprentice…

There be some good Masters and workmen that put in the second lye with the oil, with the intent that the oil might not be damaged so much by its strength, and then they put in a little of the third, and then a little of the fourth, and after that a little of the first: but there is no damage in it, for that happens for the reason that these mix-ups are made in the presence of other men, when the Master does not want them to know for fear that others should easily learn it.
The seconde part of the Secretes of Master Alexis of Piemont by Girolamo Ruscelli, 1560.

INTRIGUED?

I have found there are many historic soap recipes and formula’s available, if you know where to look. To help out the beginner historic soapmaker I compiled a collection of soap formula’s and recipes from the 10^th to 16^th century, including tidbits of soapy fun facts. Available at

https://www.academia.edu/27795669/A_most_Copious_and_Exact_Compendium_of_Sope

Several of my soap making research papers and class hand-outs are available from Academia at

https://independent.academia.edu/susanverberg

BIBLIOGRAPHY

-- (8th C) The Capitulare de Villis: Carolingian Polyptyques. English translation from the University of Leicester at https://www.le.ac.uk/hi/polyptyques/capitulare/site.html

Ashenburg, Katherine (2007) The Dirt on Clean, An Unsanitized History North Point Press, NY

Bramson, Ann Sela (1975) Soap, Making it, Enjoying it Workman Publishing Company

Clarke, Mark (2011) Mediaeval Painters’ Materials and Techniques: the Montpellier ‘Liber diversarum arcium’. London

Dunn, Kevin M. (2003) Caveman Chemistry Universal Publishers

Fioravanti, Leonardo (1588) A short discours of the excellent doctour and knight, maister Leonardo Phiorauanti Bolognese vppon chirurgerie. Translated out of Italyan into English, by Iohn Hester, practicioner in the arte of distillation. (transcribed by Susan Verberg)

Goeurot, Jean (1550) The regiment of life, whereunto is added a treatise of the pestilence, with the boke of children, newly corrected and enlarged by T. Phayre. (transcribed by Susan Verberg)

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

Moulton, Thomas (1547) This is the glasse of helth. (transcribed by Susan Verberg)

Plat, Sir Hugh (1609) Delightes for Ladies to adorne their Persons, Tables, Closets, and Distillatories with Beauties, Banquets, Perfumes & Water (transcribed by Susan Verberg)

Ruscelli, Girolamo (1558) The secretes of the reuerende Maister Alexis of Piemount Translated out of Frenche into Englishe, by Wyllyam Warde. (transcribed by Susan Verberg)

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 by William Warde. (transcribed by Susan Verberg)

Smith C S & Hawthorne J G (1974) Mappae Clavicula A little Key to the World of Medieval Techniques. Transactions of the American Philosophical Society for Promoting Useful Knowledge, New Series Vol. 64, Part 4.

Websites used:
http://www.livinghistory.co.uk/homepages/historicalballs/History%20of%20soapmaking.htm
https://en.wikipedia.org/wiki/Soap

For ingredient translations I used my personal soap related Materia Medica & Profumatoria database.

© Copyright by Susan Verberg

reproduction for educational purposes by permission only