http://www.MotherearthNews.coM 41it neutralizes acids while retaining
its ability to be dissolved in water.
More specifically, soap is a surfactant
with the unusual ability to diffuse
fats and oils into water, which is why
it can rinse away oily stains.
Soap is made by mixing dissolved
hydroxide salts, generally called
“lye,” with fatty acids. To make your
own lye that you can use to produce
a soft soap, you leach (or drip) water
through ashes to dissolve the hydrox-
ide salts. Ashes are highly concentrat-
ed minerals of hydroxides, nitrates,
carbonates, sulfites, and more. The
quality of the lye produced depends
on how well the plant material was
burned. I’ve found that the more
complete the burn (all organic ma-
terial combusted), the more hydrox-
ides will be dissolved, and the more
basic (that is, higher pH) the result-
ing lye will be. In the case of incom-
plete burns, such as you’d find in fire
pits and fireplaces, you can add lime
to the ash to help change carbonates
(charcoal) into hydroxides.
My drip lye made from ashes has a pH
of about 11, while commercial lye has a
pH of 14 — making it 1,000 times more
basic than ash lye. This is a big reason
why making drip-lye soap is so different
from conventional soap making. Because
of the lower pH, drip lye is a lot less
dangerous to handle than modern com-
mercial lye. As a precaution, though, you
should always keep some vinegar handy
during soap making because its acid will
help neutralize the lye’s base.
Making soap using drip lye
can be challenging because
the purity, density, and con-
sistency of homemade lye
is uneven. For home soap-
makers, I recommend prepar-
ing hot-process soap (which
I describe below) rather than
cold-process because an exact
amount or specific purity of
lye isn’t required for successful
saponification. In hot-process
soaps, saponification — the
chemical reaction between
lye and fat — is controlled by
added heat, not by the pH.During my research, I uncovered a
historic trick for checking the density of
drip-ash lye using a fresh egg. Because an
egg has about the same density as lye that’s
the correct strength, the egg will float.
Many colonial recipes for drip-ash lye
recommend using the homemade lye if it
can float an egg with^1 ⁄ 4 of its shell show-
ing above the liquid. This lye will produce
“Black Soap,” a strong laundry soap that
historical re-enactors complain is too
harsh. On the other hand, I uncovereda 16th century shampoo recipe that
recommends using lye dense enough
to suspend an egg in the middle of
the liquid. Suspended-egg lye makes
near-neutral soap, perfect for person-
al use because it doesn’t “bite.” This
same historic recipe also confirms the
3-to-1 ratio of lye to fat that consis-
tently works for me: “thre pottels of
lye to one pot of oyl.” It’s nice to find
confirmation that’s five centuries old!
Based on experience and histori-
cal research, I’ve developed these in-
structions for making a soft, creamy,
hot-process soap from scratch — in-
cluding homemade lye.Soft Soap in 8 Steps
1 To make a leaching barrel, drill
a small hole at the bottom of a 5-gal-
lon bucket and stuff it with a piece
of dishcloth as a filter. Fill the bucket
with sieved ashes, tamping down in-
termittently. Level the top, leaving
about 2 inches of headroom. Slowly
pour in about an inch of rainwater.
When the water has absorbed, add about
an inch more. Continue to slowly add wa-
ter until liquid starts to drip out the hole in
the bottom of the bucket — it should take
about a day. Prop the ash bucket on top
of a second bucket to collect this drip lye.
(Or, build a setup like in the illustration at
left.) You’re ready to test the strength when
you’ve collected about 1 gallon.
2 If you’ve used regular ashes from
a woodstove or fireplace in Step 1, the
drip lye will be dark brown and prob-
ably won’t suspend an egg.
Slowly heat the drip lye and
allow it to evaporate until
it has the desired strength,
which is likely about a quar-
ter of its original volume.
Use stainless steel vessels for
heating lye, never aluminum
(which creates noxious gases
in combination with lye) or
enamel (which lye will etch).
Cool down the lye before
soap making. Contaminants
will settle to the bottom. The
next day, pour the purer lye
solution off the top (that is,
decant it).1
2
SuSan Verberg (7); top:amandanagengaSt;page 40:matthewt. Stallbaumerp 40-42 Soap.indd 41 10/10/16 10:00 AM