Making the perfect jar soy candle
Ok, so maybe it's not a perfect candle, because nothing is perfect, but here is my process for making an awesome "16 oz." jar soy candle. 16 oz. is in quotes, because the jar really holds 475 ml by volume, and you wouldn't fill it completely up to the top anyway. Plus, it doesn't really weigh a pound either. I spent three years perfecting this soy candle making technique, and I'm giving you the recipe for free, right here, because I think everyone should have safe, well made soy candles to enjoy.

Needed materials:
~ soy wax pastilles: I bought my wax from Enchanted Lites. I blended a natural additive called Panalite in at 1/2 Tbsp per lb to make the wax a bit harder and more stable, but you could save the hassle by trying their Millenium blend, which is also really good, and already has additives.
~ 475 ml 12-sided glass jar: these are often called 16 ounce Classic jars. They sometimes come with a gold screw-on lid. I covered the lid with fabric and raffia to give it a "homespun" look. One place you can buy these from is Lone Star Candle Supply  you'd want to find a company close to you, to save on shipping costs.
~ Appropriately sized pre-tabbed wick: I started out using German coreless CD16 wicks from Nature's Garden, then switched to RRD-47 wicks from Just By Nature, and finally changed to ECO-10 wicks from Candle Science. All of these wicks work really well for this sized jar with soy wax with additive. The ECO wicks do mushroom more than the other two, but nothing horrible. You want a nice clean melt off the sides, but the glass shouldn't get so hot that it might crack. If you are worried about the jar getting too hot to touch, you might want to go down one wick size just to be safe.
~ Candle fragrance oil (optional): I love fragrance in a candle, but some people are sensitive to it, which is why I say optional. I have purchased fragrance oils from many different supply companies, and found none of them to be bad. Choose a company that will send you free or very inexpensive samples, so that you can try them before buying a large quantity. I found Enchanted Lites to be really easy to work with. They have great customer service.
~ Other items: You'll want to use a wick sticker, and something to hold up the wick while the candle is setting up, like a wick holder or a popsicle stick. You also might want to put a label on your candle, and you ALWAYS want to put a warning label on the bottom. Candle dye is also optional.

Step one: Weigh out your wax pastilles and melt them in a double boiler, or in a Presto pot (A Presto 6 Qt. Kitchen Kettle Multi-Cooker, which you can find at most department stores for around $20). The nice thing about soy wax, is that you can melt it in a Presto pot, whereas paraffin needs to be melted in a double boiler, for safety reasons, and it seems to take forever to melt. Soy wax melts very quickly in a Presto pot, so you should carefully watch with a candy or candle thermometer, to not let it get too hot and smoke. You might scald the wax then, and it will be a darker color. Some people say you should melt the wax first, and then throw in your additive (Panalite, stearic, or whatever you want to use), but I throw it all in at the start. It seems to melt the same either way. Bring the wax to around 160 degrees F.

Step two: measure the melted wax into a measuring container. A Pyrex measuring cup works well, but so does a 500 ml graduated flask, which you can get from a laboratory supply company. That's what I use, and they are very sturdy, as long as you don't throw them around. You will want about 375 ml of wax for your container. This, together with fragrance oil, should fill the container right up to the spot where the side curves in at the top.

Step three: weigh the fragrance oil, hereafter referred to as FO. Actually do this step while the wax is melting. I found about .7 ounces to work very nicely, that's point 7, not 7 ounces:-) You could go up to a whole ounce, but it probably isn't necessary. Use a small electronic scale to accurately weight the FO. You can't really go by volume, because some FOs are heavier than others. You want to go by weight to get the right percentage of FO to wax. Your goal is around 7%.

Step four: Right after you measure the melted wax, add your FO slowly to the same container, stirring constantly. Keep stirring for 20 - 30 seconds to completely incorporate the FO into the wax. Allow the melted wax to cool to about 120 - 130 degrees F. If you want to add candle color/dye, add it right before the FO, while the wax is at its hottest.

Step five: Do this while the wax is cooling. Apply the caution label to the bottom of your jar, and apply your wick, with the wick sticker in the center of the bottom of your jar. Center your wick and hold it steady with the wick bar or popsicle stick.

Step six: Slowly pour your prepared wax into the jar. Pouring it very quickly may develop bubbles. Soy wax is tricky, and may develop air pockets within the candle. I always touched up the tops of my candles with a heat gun after they cooled. This eliminates any air pockets near the surface. Sometimes you just get air pockets no matter what you do, and I gave up trying to find a way to pour or cool them without craters and pockets, and just used a heat gun. Its easier than trying to control the elements, and a lot less maddening.

Once your candle is hardened and cooled, it's done. Try this method and combination of  materials and see if you don't agree it makes the best soy candle ever.