How to make medieval soap

Many household items that we take for granted and can be easily purchase were much more difficult to acquire in the Middle Ages. People would often make things for themselves, including soap. If you want to try this for yourself, there is a fourteenth-century English recipe with detailed instructions on how to make white soap.

The text is from the Trinity Encyclopedia, which was written in the late fourteenth century in Middle English. The text, which has just been edited and translated by Mark Clarke, is unusual in that offers very detailed recipes. Most similar works from the Middle Ages do not offer very comprehensive instructions, assuming that the reader already knew the basics. The Trinity Encyclopedia this collection offers dozens of recipes with step-by-step directions, including creating pigments, dyeing clothes, preparing leather, and even making pearls look better. It also has several recipes for making soap. Here is one that ‘To make white soap in another manner’.


What you will need:

  • Ashes from an oak tree
  • Tallow – which is animal fat
  • Lime – which is heated to become quicklime
  • Salt
  • Flour
  • Water
  • A pot
  • A pan
  • A strong stir stick

The recipe begins by telling you to put “clean shifted ashes of oak” into a pot that is three or four gallons in size, and then add two gallons “scalding hot water to it.” Stir, cover and let this sit for an entire day. This mixture is now called lye, and then you add “two generous ounces of quicklime” as well as two more gallons of boiling water to it. Stir and let stand for another day.

The recipe then explains:

And then take three quarts of that lye and put it in a brazen pan three potels [a potel is a type of small pot] and make it seethe, and then when it does, immediately take and add to it half a pound of nice clean tallow of a sheep that is completely melted beforehand. Then take a good large stick, or else a pot-stick, and stir your materials together well with it. And when your tallow is completely molten in your lye, take and add to it half an ounce of nice white salt and stir them together well; then take a quarter of an ounce of nice wheat flour and mix it with a little portion of your cold lye, and then draw it through a linen cloth into a dish in the manner of a starch; and then put that same ‘starch ‘ to your other materials in your brazen pan, and then stir them well all together with your pot-stick; and if it rises up, take it and beat it back down with a ladle, and continually be stirring in it until your material becomes so thick that you can see the base of your vessel during the stirring, and also such that it stands when you push it with your pot-stick without any running together again, that is the true sign of when it is enough.


The recipe notes that the lye and tallow might not mix well together, then you need to keep adding more lye to it – one quart at a time – “until your materials hold themselves all well together in your pan without any separating or parting one from another.”

The recipe then concludes:

When it is at that aforementioned state, take it down from the fire and put it in a mould that is moistened beforehand with water, and set it on a level table, and so let it dry up in that same mould into a nice cake of soap as the manner is, and then it is done.

The recipe finally adds that you can make large portions if you want, but you will just need bigger pots and pans and greater quantities of ingredients.

This recipe, and many others, can be found in Tricks of the Medieval Trades:: A Collection of 14th Century English Craft Recipes, by Mark Clarke and published by Archetype Books. Click here to read more from the book, which you can buy from the publisher or on


Top Image: Detail from British Library MS Royal 10 E IV f. 108