MEDIEVAL BLEACHING
(Prior to the advent of bleaching
chemicals in the late 18C)
SUMMARY
Linen has been widely used
for centuries, white being the preferred colour, but if a colour was desired,
the fabric had to be bleached first for the fibres to take the dyes. So, I have attempted to bleach natural
coloured linen (which is a beige or light brown) to white using methods and
solutions that were used in the middle ages.
Up front, I would have to say I have failed in that I did not produce white as we know it, and
wondered if whites were really white then as we know them now; I believe
not. I feel somewhat vindicated in this
by such comments as: “After weeks of bleaching, the linen turned a milky white. The snowy whites of today were not available
until chlorine was discovered in the 1780s …”[1].
Just to see how much better
the modern chemicals were, I also did four experiments with modern products,
hydrogen peroxide, Shout, Oxyclean and Javex bleach. The results are no better than with the
medieval processes. I had read that one
should never bleach linen with Javex bleach, I found out why; the fabric practically disintegrated, granted
I used it at 50% strength.
I researched several
different ‘recipes’, i.e. different solutions used alone or in conjunction with
one or more others, alternating sometimes with each other or with laying out
wet on grass in the sun, and beetling or beating the linen. These solutions include lye in various
strengths, cow dung, cow urine, human urine, buttermilk, fermented bran, sour
milk, and so on. Often the process
involved alternating an alkaline solution with an acid one, to neutralize it.
Suffice it to say, at the
very least the woven linen fabric (also called web) and/or linen clothing was
boiled or soaked in a specific liquid, then laid out on mown grass wet, kept
wet, and exposed to light, usually the sun.
In the appendices (once I figure out how to insert them) you will find the different recipes I used and the sources of some of
them. Out of curiosity, I also used some
different recipes of my own, including each of the solutions on their own.
Preparation
In the fall of 2012, as I was
researching, I began gathering some of the materials I would need, such as hard
wood ashes, cow dung, sheep dung (which I ended up not using). I also wanted a space I could use without
bringing everything into my kitchen, so I built a ‘mucky kitchen’ outside under
my deck to have water, sinks, counter space, etc. I plumbed the sinks into a drain in the
corner, used my Coleman camp stove for boiling and purchased some used
saucepans to dedicate to the purpose.
I sieved any remaining
charcoal out of my ashes and made several batches of lye. I did check it to see if it was at the
strength of being able to float and egg or a potato in it, as quoted for soap
making, and it was not, but I only found reference to that in one place so I
considered it not to be important for this purpose.
Fibres and yarns are normally
scoured (boiled) by way of finishing. I
have no idea how my commercial fabric was finished so I scoured my one yard of fabric
several times, for a total of ten hours before cutting it into 16 pieces for
the experiments and marked them with ID numbers. I could have had a more logical numerical
sequence but I felt it was advisable to keep to what I started with. Several times over the process, other
possibilities would present themselves as a result of my research, and some of
the samples were cut in half to accommodate.
Over the winter
I undertook the sun on snow (see sample 25) and frost with moonlight (see sample 14) experiments I had read about. The weather was not wonderfully cooperative so that sometimes the moon was not visible when temperatures were below freezing, other times when it was out, it was not freezing. I could see a slight difference from month to month, but the lightening with moonlight overall was not significant. The sun on snow experiments lightened more, but nowhere near white.
Why moonlight? There is a reference to an old Slav
custom[2]. Further, Robert Mudie (also the author of "the British Naturalist) writes in his “A Popular Guide to the observation of Nature", 1836.
"Now
our moonlight really comes from the sun, and is reflected to us from the
surface of the moon, just as we can throw light in a dark room by a mirror, or
by whitewashing a wall opposite the door on which light can fall. Now the heat
of the sun's light, and also the greater part of the red rays, enter into and
are absorbed by the moon : and thus moonlight wants the golden brightness of the
direct rays of the sun, and is in consequence silvery, and has a little of a
bluish tint in it."
I found a wonderful essay[3]
written in the 1770s by an unnamed author, which described all the processes in
great detail, whereas all other references were relatively limited in
detail. Inasmuch as the processes
described therein are similar in almost all situations to what I had read about
occurring before 1600, and the bleaching chemicals were only just starting to
be discovered at this time, I considered this book and its contents to be of
great value to the process. Anything
mentioned in this essay that was not mentioned anywhere else was not used, with
one exception. The author believed that
it was the action of the evaporation of the water from the fabric that took the
colour from it. He conducted several
tests to prove his theory. I therefore
wished to see this for myself, so I put one sample outside, under my deck roof
the same amount of time I put one out for the frost and moon sample, wetting it
for the same length of time for each (see
sample 26). I also undertook a
similar experiment, no direct sunlight, in the spring but without freezing
temperatures, for the same number of days/nights (see sample 10a). Both lightened from the original but not as much
as those exposed to sun or moon light.
The main work of summer bleaching
The linen is laid out wet,
in the sun on ‘freshly mowed grass’ because there is a chemical reaction
between the chlorophyll in the grass and the sun. It is important that it is kept wet, some
actually say not to allow it to dry out, and I had found this to be
significant. I had done a very simple
experiment a few years ago to use only water and the sun to bleach a piece of
fabric. I found it reached a significantly
lighter colour, though creamy white not pure white, in about 15 sunny days when
sprinkled several times a day than when it was just put out wet in the morning
and not kept wet. The experiments I have
done over the past few months did not achieve quite the same level of
lightening in as short a time. I have
two theories as to why this may be the case.
i)
The fabric used 3 years ago was hand woven from 75% commercially prepared
thread and 25% handspun from commercially prepared fibre. The fabric used for the experiments this year
was commercially prepared fabric upon which various unknown processes may have
occurred or sizing used which may require other processes or substances to
remove. Unknown substances may have been
applied to the commercial thread I used for the handweaving but my point is
that it is a case of comparing apples to oranges, rather than apples to apples.
ii)
When I did the original test, it was mid-summer when the days were longest and
the sun the strongest. When I started
the experiments this year, while some of the experiments ran from April to
October, I started in April when there were fewer hours of sunlight in a day
and the grass was pretty sparse.
I made up tracking sheets
for each sample so I had an easy guide to follow each day as I was doing
different things to different samples, and proceeded to boil, soak, rinse,
grass, as indicated. See Appendix 5 for
a completed tracking sample. Please
refer to Appendix II for the various procedures/recipes I used and Appendix I
for the most reliable sources and references/bibliography.
On one occasion, I forgot my
sample was boiling away, and it boiled dry and burned the fabric. That was experiment #13. Go figure!
Reconciling what I understood
to have taken place in the middle ages with what I was able to do.
What did they do in
period?
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What I did?
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What and why when I did
things differently
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12-15 hours sunshine
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8-10 hrs
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That’s all I get
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Beating 2-3 hours
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2-3 minutes
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Because I was working with
small pieces of fabric while they were working with miles of yards
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Boiling or soaking in
various substances, such as the lye, urine, etc. I have no way of knowing if
they reused the solutions over and over again or started fresh each time
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I used them over and over
|
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They used various alkaline
and/or acid substances, sometimes alone, sometimes combined, sometimes
alternating, and always followed by laying out on mown grass wet for weeks or
months, and kept wet or sprinkled frequently, several times a day.
One common process, known
as ‘bucking’ or ‘bowking’ involved laying the linen yardage in a raised
wooden barrel folded in a specific way and with sticks laid across at
intervals to permit the flow of liquid, then a cloth, likely linen, was laid
over the top of the barrel and secured in place around the rim.
Ashes from hard wood were
spread over this cloth and boiling water poured over them so as to run
through the ashes, through the cloth over the top of the barrel, and trickle
down through the layers of linen fabric so as to wet it thoroughly. This water then became lye (or ley) which
was subsequently drained from the barrel by means of a tap or plug at the
bottom of the barrel for the liquid to run into another container where it
was collected, reheated and poured back again through the ashes and the
fabric several times.
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I used the same process
but not likely in the same containers such as a wooden barrel for bucking
with lye.
Bucking: because I was
only working with small pieces of fabric, it did not make sense to replicate
a whole barrel full of yard goods. Therefore,
I made lye by filling a 4L plastic milk jug supported upside down with the
bottom cut off and a cloth filter tied over the mouth, and set over another
container to catch the lye.
Then when I was to apply
the lye to the fabric, I brought it to a boil in a pot and added the fabric,
then left it to steep in the lye for the prescribed amount of time.
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My intent was to immerse
the fabric samples in the same solutions in order to attain the whitened
effect but not to necessarily replicate all the pieces of equipment used.
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Questions I still have
Did they use actual soap
of any kind, besides the lye, which I did not find described as having been
mixed with animal fat to make soap, in this context.
|
Although I found the word
‘wash’ here and there, which implies the use of soap in my mind, I did not
find reference to soap in relation to the bleaching, so I did not use any
soap beyond the washing soda used to scour the fabric before the experiments.
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Water
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I presumed they would have
used rainwater, or stream/river/pond water, so I used unadulterated rainwater
for boiling and rinsing. I think I
probably used mains water when scouring.
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Did they suspend the linen
over grass.
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I wondered if the fabric was
just laid on the ground/grass or if it was pegged down or suspended
somehow. One of the references I found
spoke of loops being made at intervals down the edges of the length of the
yardage and sticks being inserted in the loops and stuck into the ground in
order to suspend the fabric just over the grass. I used modern safety pins at each corner
and make U-shaped loops with wire to pin them down, some of the time; when it
was windy it was sometimes necessary to do something to keep them from
blowing around
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Did they lift it up daily
or when raining
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I gave this some thought
and felt that picking up what in some cases amounted to miles of yardage just
because the sun wasn’t shining (as I did at first with mine), wasn’t very
practical. It not only rains more
often in
That being said, I did
read in more than one place that it was turned over frequently, even daily. One reference spoke of it being common
knowledge that the linen would lighten more on one side if it were left the
same side up all the time. I had found
this to be the case when I bleached the first piece several years ago, as it
was already hemmed and the lightening did not go into the hem.
I turned my samples over
every day so they were lightened the same on both sides.
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Full sun full day daylight
hours
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Here I had
limitations. Most farm fields, bleach
fields, have full sun all day from dawn to dusk, or as long as the sun is
out, without anything impeding the sun.
At my home, when the sun rises at 6 am, it will not be shining on any
part of my property, except perhaps the roof of my house, until about 8 am
because of trees and hills to the east.
Likewise, at the end of the day it is gone from my property a couple
of hours before it officially sets. Therefore,
the hours my experiments could sunbathe were reduced to about 11 from 15 at
the longest daylight hours.
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6 months
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Some references spoke of
doing this for 6 or even 8 months of the year. I had planned to go from mid April to mid
October. April this year was quite
cold and not very conducive to playing in water outside, so I did not get most
experiments started until April 25th, and the latter part of
October it rained almost every day, so I gave up on the remaining four on
October 23rd.
Also, I planned for the
six month samples to be out in the sun for 180 days, but every day they were
soaking in something was a day less in the sun; likewise rainy days, or days
I was away. So the process lasted for
six months but not 180 days in the sun.
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Did they use fresh liquids
each time, other than the quoted use of waste ley or lye, which I understand
to mean reusing.
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I have no way of knowing
whether fresh liquids, be it cow dung liquid, urine, lye, etc. were used each
time that a second or third etc. immersion was applied, or whether they would
have re-used the same liquids used for the first application. For practical reasons, I reused them and it
is possible that while boiling some colour out of the fabric, the colour may
have remained in the liquid and even possibly have re-entered it on a
subsequent use.
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After a few weeks, I discovered
that several of the samples had darker threads in them, which appear to have
been inherent in the original commercial fabric, especially noticeable when wet, and which I deduced to be a quality control issue. Those samples that underwent boiling in
several different solutions seemed to resolve this problem but in the meantime
I decided to add a handspun handwoven piece without these darker threads to the experiments for comparison purposes, and no darker threads developed (see 10b) 
.
Some of the samples that were laid out on the grass the longest actually took on a greenish tinge, which rinsed out when boiled in clean water, and the darker threads are more prominent
Conclusion
So it would appear that experiment
#8, which had the highest number of boilings, which combined with alternating
sunbathing for the longest period of time, is marginally the lightest. However, experiment #1, which was plain water
only and one month only, came in close behind in fourth place.
* * * * *
Bucking (pouring hot water through ashes – lye – on
linen in barrel)
Two photos of the total
experiments taken after presentation
