Tuesday, April 17, 2012

The Pencil Line

My pencil-line Eucalyptus Clove soap
If you are a soap connoisseur (and I am assuming that you are), then you may have seen or made a "pencil line" in a bar of soap.

I was new to all of this pencil line stuff until recently. I had seen it done, but had never tried it myself. What is a "pencil line"? See the thin brown line between the two layers of my soap? That's a pencil line. Such lines are made by dusting a layer of mica, cocoa powder, poppy seeds, ground spices, ground coffee, charcoal powder, etc., in between soap pours. When the bars are cut, the line runs through the width of the soap, looking like it was drawn with a pencil.

One of my mom's favorite soaps is scented with a blend of eucalyptus and clove essential oils. When my folks came to visit last month, I gave her the last of my Eucalyptus Clove soap. Knowing how much she likes it, I made some more since I was plumb out. I figured it would also be a good time to try out the pencil line.

Because this was my first time playing with this technique, I kept things simple and did not color my soap or try to do anything too artsy so I could focus just on the pencil line. I thought about using ground cloves for my line, but decided against it, worried that it might be too scratchy or possibly a skin irritant. So I used some Cappuccino mica instead.

I made my batch of soap as usual and brought it to a medium-thick trace. I poured about half of the soap into my mold and then scooped a bit of mica into a tea infuser. (Any small sieve will also work.) To make the pencil line, I gently tapped the side of the infuser while moving it over the soap, creating a thin layer of mica. (Take care not to make too thick of a layer - the soap can separate if too much mica or powder is used. You just want to barely cover the surface of the soap.)

Dusting soap layer with mica (l); soap with a thin layer of mica (r)
After tapping out a layer of mica, the sides of my mold were sullied. I wiped the inside of my liner with a paper towel to clean it up. Otherwise, I would have ended up with splotches of mica all over the outside of my soap when I poured the next layer.

Wiping mold clean
(You probably noticed that I'm not wearing my safety gloves in the photos above. I confess that I did take my gloves off to tap out the mica line and to wipe my mold clean - I needed precision for those parts of the task, and my gloves give me big clumsy oaf hands. After I was done wiping my liner clean, my gloves went right back on.)

By the time I was done fooling around with the mica, the remaining soap in my mixing bowl had set up quite a bit and was thick. The first layer was poured at a fairly heavy trace, so I felt confident it could support the next layer. I poured the second layer over the back of a spoon so that the soap wouldn't break through the first layer, disturbing my mica line.

Pouring the rest of the soap over the back of a spoon
When I was done pouring, I tapped the mold on the countertop a few times to work out any air bubbles, covered the top of the soap with cling wrap to prevent ash, and insulated the mold so the soap could gel.

A few days later, it was time to cut. Here's a tip for cutting soaps with a pencil line - turn the soap onto its side and then cut it. If you cut top-to-bottom, you'll drag your line through the soap. Cutting the soap on its side keeps the line nice and crisp. And also wipe your blade clean after every cut. (This tip also works if you've got something like calendula, oatmeal, seeds, jojoba beads or whatever sprinkled on top of your soap. Ever cut your soap and had the stuff on your decorated tops drag through the soap, making grooves? Try the side-cut to avoid that.)

Cutting proved trickier than I was expecting. My soap mold has handy-dandy cutting notches built into it so I can make standard cuts, but my soap was too tall to fit inside my mold on its side. Lining up my cutter with the grooves from high up was imprecise, and because my cutter has a thick wooden handle, it wouldn't cut all the way through the soap anyway.

So, I took the soap out of the mold so I could line it up with the edge of the mold and the cutting notches. I used my cutter to mark where to cut and then did my best to make a straight slice with a chef's knife. I am the worst at freehand cutting, but I did okay with my notches marked off. The bars aren't as uniform as I would like, but they're not bad.

And how thrilled was I that the soap didn't separate when I cut it? Very, that's how. I worried I was a bit heavy-handed with the mica in parts, but I guess I did all right.

The pencil line technique is definitely something I want to play with again. I want to experiment with bringing the line higher up the soap. And while I like how straight my line turned out, I rather enjoy some of the soaps I've seen with imperfect pencil lines - lines that slope a bit or have a couple of small ridges in them. Perhaps I need to work some texture into the soap layer before dusting the line to achieve that effect.

Do you like pencil lines? Ever made one? What are some of your tips? Do you like perfectly straight lines, or do you like lines with a bit more character?

Sunday, April 1, 2012

The Dreaded Soda Ash

Gingersnap bars with heavy ash
If you make soap, you've probably had a few batches develop a whitish powdery layer on the tops. If you buy handmade soap, you may have seen this sort of thing. What is that stuff?

It's ... dah, dah, daaaah! ... soda ash.

What is soda ash? Conventional wisdom states that soda ash is sodium carbonate, which results from sodium hydroxide (lye) reacting with carbon dioxide in the air.

There may be other explanations for this phenomenon, though. In her book "The Soapmaker's Companion," Susan Miller Cavitch suggests that the powdery substance may just be dried soap. Glycerin, a natural by-product of the soapmaking process, attracts moisture from the air. Cavitch theorizes that the soap molecules closest to the surrounding air draw in moisture and then dry, forming tiny crystals. Her theory has been tested by a chemist, who could find no trace of sodium carbonate in the ash on her bars.

Beer soap with soda ash
Another idea is that soda ash could be minerals from the water in the soap collecting on the surface. This is one more reason to use distilled water for soapmaking, although I always use distilled water and still sometimes experience heavy ash. I have also experienced ash using beer in place of water.

Many factors can influence whether or not ash will form: temperature, batch size, fragrance or essential oils, humidity, soap density, or the soap recipe itself.

The origins of soda ash may be somewhat of a mystery, but one thing we can agree on is that it is harmless. (A thick, crumbly crust is another story - such a thing as that probably indicates lye-heavy soap.)

I think another thing that most of us soapmakers can agree on is that it is a total pain in the ash.

So, now that you kinda-sorta-not-really know where soda ash comes from, how can you prevent it from happening? I sometimes gently place a sheet of plastic cling wrap over the top of my soap after pouring it into the mold to prevent the surface from coming in contact with the air. This is fine if your tops are flat, but it doesn't work so well if you have textured tops. Another thing you can try is liberally spritzing the top of the soap with 91% rubbing alcohol after pouring.

Some folks don't mind ash. Soapmakers sometimes embrace it as part of the process and feel that it lends a rustic handmade charm to the soap. And soda ash tends to just wash off the first time anyone uses the soap, so it needn't be a huge concern to the soapmaker or the customer.

But it's just not pretty. And to the untrained eye, it can even look like mold or fungus (which it's totally not).

So let's say that you don't want soda ash. Let's also say that you get some despite your best efforts to avoid it. How can you get rid of soda ash once you get it?

This video by Soaping101 explains what soda ash is and offers up four methods for getting rid of it - alcohol, water, glycerin, and steam:

In the video, Soaping101 tries all four methods: spritzing the finished soap with 91% rubbing alcohol, dunking the soap in water, painting the soap with a bit of glycerin and colorant, and steaming the ash away. The conclusion was that while all methods removed some of the ash, steaming seemed to be the best bet.

Remember the photo of my Gingersnap soaps at the beginning of this post? I made that batch in September and it developed heavy soda ash. I had a couple of bars leftover and had never taken the time to try to remove the ash. The soap I make is just for me and my family, so I wasn't too worried about getting rid of it. A while back, someone on one of the soapmaking forums I belong to mentioned using steam to get rid of soda ash. Intrigued, I poked around the interwebs a bit more and found Soaping101's video. I liked the idea of using steam. Sure, you can slice the ash off, but then you mar the top (and waste a bit of soap). Rinsing with water can also mess up the tops. But a quick steaming would get into the nooks and crannies and it wouldn't interfere with the soap, which is great for textured tops, fancy peaks, or tops sprinkled with oats or seeds.

Since these Gingersnap bars had such heavy ash, I thought they would be good candidates for a blog feature and I decided to give the steaming method a try.

Holding bar over steam (l); After steaming (r)
All I did was simmer some water in a pot on my stove and then hold the soap over the steam. (The soap can get a little slippery, so I held it with a paper towel.) You could also use a tea kettle or a clothes steamer, whatever steam-errific thing you want. After a few seconds, the tops of the soaps looked a bit wet and the ash seemed to disappear. I let the bars dry on my curing rack for a few hours. Several days later, the soda ash was still gone.

(You may be wondering what the deal is with the yellowish parts in the photos above. I tried to swirl some gold-colored soap into the tops, but it didn't really work. I think I fiddled with it too much. I also wanted textured peaks, which didn't really work either. I still have the hardest time with that.)

So, I think in the future I will use the steam method to get rid of soda ash. It's quick, easy, and effective and it won't screw up the soaps.

Got any soda ash woes, my soapy friends? Does ash bother you as either a soapmaker or a customer? How do you like to get rid of it? Or do you prefer to just roll with the ash and keep it?