Category Archives: Tutorials

Patching Up Soap

I have been meaning to do a tutorial on how to patch up the inevitable holes that appear on soaps every now and then. To show you how overdue this post is, the pictures below were taken last August 6, 2014. The photos were hastily taken using my camera phone and not in the best possible light.  I will confess that I don’t like taking pictures of soaps that have not been cleaned up, and the only way to get through the chore was to do it quickly.

Holes are nothing but trapped air bubbles.  They usually appear in soaps with design, and especially when the soap batter starts to thicken before it can be poured into the mold.  Banging the mold helps release trapped air but doesn’t guarantee complete removal. Just like soda ash, holes are nothing but an aesthetic nuisance, and the ones most bothered by them are the soap makers.

Some soaps are simply beyond repair and are better off rebatched or chopped up as embeds. Most, however, simply need a little reconstructive patching up and they’re good as new.  It takes time, patience, and a light touch to leave as little “scarring” as possible.  Some can’t understand the work that goes into prettifying soap that’s just going to melt anyway, but soapmakers tend to be quite passionate and obsessive about their craft.

The other day I downloaded a free photo editing program called  PicMonkey . I learned about it sometime ago from another blogger.  I wish I could remember whose blog it was!  Anyway, I felt like a child that had just gotten a new toy.  As you can see, I am showing off the collage I made. (Ok, I got a little bit crazy and I also downloaded BeFunky for my iPhone. I arrived late to the photo editing party and I’m making up for the missed fun :p )

Patching Up Soap

1.  This was my first camo soap.  I made my own fragrance blend with woodsy notes of oak and fir, balanced out by honey, saffron, vanilla, and eucalyptus.  It smelled awesome and was popular with the boys, but it accelerated trace, hence the the holes.

2.  For this simple operation, we need an offset spatula, toothpicks, and soap trimming to fill up the holes. The triangular thing beside the spatula is some kind of pottery tool that I picked up when I went to Jingdezhen last year.  I don’t know what it’s called, but at that time I thought I could use it as a swirling tool.  Well, I never used it for swirling, but intuitively it was perfect for smoothening surfaces – soap or otherwise!  It’s great to have, but an offset spatula is perfectly sufficient.

3.  Like a dentist, I probe how deep and big the cavity is using a toothpick.  Some holes may appear deceptively small, but is actually a long tunnel under!

4.  Once you’ve assessed the size of the cavity, massage the required amount of soap trimming into a smooth and malleable ball or log – the consistency of play dough. Push the soap into the cavity using a toothpick.  Keep at it until you can’t push in any more.

5.  Flatten patched-up portion with the offset spatula. Wipe it clean. Tilt it at an angle and scrape off excess, in the same way that I did with the pottery tool in the photo.

6.  And there you have it!  After the soap fully cures, the colors will even out and the patches will hardly be noticeable.

woodland camo

Lye Master Batch: How to Make and Its Application

I will be out of town the next couple of weeks.  It will be a reluctant break from my soapmaking mania, but I am excited to be in Honolulu for the Hawaii Food and Wine Festival and to be visiting my sister in California after. Yipee!!!

Before I take off, here’s a tutorial on lye master batching.

LYE MASTER BATCHING, 1:1 ratio or 50% concentration

1.  You will need:

  • 2 liters distilled water
  • 2 kilos sodium hydroxide/NaOH/caustic soda (pearls or flakes)
  • 1 chemical-resistant plastic container* that can hold 1 gallon or minimum 3 kilos
  • 1 large bowl or basin that can hold the plastic container
  • 1 digital weighing scale
  • 1 pair gloves
  • 1 pair safety goggles
  • 1 long chemical-resistant stirring spoon

*To learn more about what’s safe to use, you may want to check out this forum thread. Avoid metal containers as you run the risk of turning your lye solution gray, and always have a container with a bigger capacity than what’s going into it.

lye masterbatching check list

2.  Although you can mix the solution in the kitchen with the exhaust turned-on, I prefer to do it outside for better ventilation as the fumes are very biting and strong.  Just for added precaution so that the lye solution does not overheat, I always place the mixing container in a bowl filled with cold tap water (think nuclear reactor). With safety gear in place, it’s time to pour the NaOH into the container with distilled water.lye masterbatching 1

3. Cover your nose (I just hold my breath) and stir until the NaOH has been completely dissolved.Lye Masterbatching 2

4. Cover the container loosely to prevent debris from going in and to prevent rapid evaporation. If I make the lye solution before going to work, I transfer it to a bathroom that no one uses.  By the the time I come home, it would have cooled down already. Alternately, this can be done at night and left to cool down overnight.

Lye Masterbatching 3

Right after mixing, the solution gets very very hot, near boiling.  Look at the water bubbles forming from the heat:

Lye Masterbatching 4

5. When the solution has completely cooled down, give it a good stir. I also like to strain it before it goes into the jug. Make sure to clearly and properly mark your container and store in a place where no one will accidentally bump into it or mistake it for something else.  (I store it under the kitchen sink)

lye master batchThe net weight of the solution is 4 kilos or 8.8 pounds, but since the solution is very dense, its volume is approximately a little over half a gallon.

lye masterbatch 1


To avoid confusion, I will be using the term lye pre-mix to mean master-batched lye solution and NaOH to mean DRY lye or caustic soda.

Let’s take an example and assume these were the numbers shown after running your recipe through a lye calculator:

                  Water 265 grams          NaOH 130 grams

→ Multiply the called for NaOH by 2:

                 130 g. NaOH x 2 = 260 g. lye pre-mix

→Subtract NaOH weight from water amount (lye calculator amounts):

                 265 g. water – 130 g. NaOH = 135 g. additional liquid

(Explanation: Remember our lye pre-mix is half water, half NaOH. Thus, to determine how much pre-mix to use, we have to double the NaOH quantity called for in the recipe.  Correspondingly, we have to deduct the water in the pre-mix from the total liquid required to know how much more to add.)

In a nutshell:

A recipe that calls for 130 grams NaOH and 265 grams water would need:

                 260 g. lye pre-mix + 135 g. water

To double check that your conversion is correct, the sum of the numbers of the original recipe should be the same as for the pre-mix:

Original recipe:            265 g. water + 130 g. NaOH = 395 g.

Recipe with pre-mix:   135 g. water + 260 g. lye pre-mix = 395 g.

Note: Mixing the lye pre-mix with additional water or any form of liquid will cause the whole thing to heat up again!  Unless you actually prefer to have it hot to melt hard oils or for whatever reason, I suggest mixing your water/milk/juice directly into the oils, then adding in the lye pre-mix after.

I hope my tutorial was clear and didn’t make you more confused 🙂 .  For additional information, there are several forum threads out there, just google “lye master batching.” I would also highly recommend reading Kevin M. Dunn’s Scientific Soapmaking.  From his book, I learned it was possible to have a 50% lye concentration, and even though it does not talk about master batching, it helped me to understand lye and water percentages/discounts and just about all the nerdy stuff behind soap making. (Ok, there was a lot of hard core chemistry and equations that I skipped. I only read portions that interested me 🙂 )

I don’t master batch my oils because I like playing with different recipes, but I can’t imagine going back to weighing and mixing lye every time I have to make soap.  I just love the ease and convenience, and in my opinion, it’s really no more dangerous than having to dissolve solid NaOH every time.  Needless to say, extra precaution has to be taken when dealing with any hazardous substance.

When I need to use some lye pre-mix, I just pour directly from the jug. I don’t even shake it because I think the the NaOH has dissolved and bound completely with the water. But that’s just me.  I guess there’s no harm in shaking it up a bit before using, if that makes you feel better.

Happy soaping! 🙂

Removing Soda Ash Efficiently

Nowadays, when I am making soap, I don’t think about soda ash anymore.  I have taken a zen approach to it: if it’s there, then it’s there; if it’s not, then well and great.  But previously, I was really on the hunt on how to avoid it. I tried all sorts of tips gathered from books and the internet: from using beeswax, to spraying with alcohol, to covering the soap surface, to steaming. From my experience, beeswax does not guarantee a soda ash-free soap; the same goes for spraying with alcohol. Covering the surface works, but it can leave crease marks and air pockets; steaming works too but it is time consuming and a bit dangerous to hold a soap bar over a steaming kettle.  I’ve also tried holding an entire loaf over steaming water. Some of the ash came back after a few days, but it could be that the soap was getting slippery so i did not get to steam it long enough.

Last June, after making a batch of soap that had soda ash, it started to rain.  The following day, I noticed that the ash had disappeared and the soap was a bit moist from the high humidity. This gave me the idea to place a “tent” (using an inverted container) over the soap, together with a bowl of hot water, to trap the steam. So far, I’ve found this to be the most efficient and effective way of removing soda ash.  For bigger batches, this can be done in an oven or in any enclosed space for that matter.

Here is a batch of ashy lemongrass verbena soap that I steamed this afternoon.  While it was steaming, I took pictures of my other soaps.  I estimate that I left it to steam for around 20-25 minutes.

Lemon verbena soap covered with soda ash.

Lemon verbena soap covered with soda ash.

Steaming soap.

Soap being steamed.

Soap right after steaming.

Soap right after steaming. This is another one of my colour-challenged soaps 🙂

Here’s another batch I steamed:

Japanese Cherry Blossom   soap before steaming.

Japanese Cherry Blossom soap before steaming.

After steaming.

After steaming.