Sunday, June 14, 2009

Bison Soap

Today I made my first ever batch of soap. My brother took a soapmaking class a number of months ago so he guided me through the process. First I looked for a recipe using bison fat but couldn't find one. I guess not many people get their hands on bison fat these days. Meanwhile my brother and I have 5-gallon buckets full. :)

I substituted beef fat when looking up how much lye to use. Hopefully I calculated it correctly. It's something you really don't want to mess around with. If your lye to fat ratio is wrong then you might end up with a chemical burn like Ed Norton in Fight Club. I had the balsamic vinegar standing by just in case.

The recipe I created was:
  • 1 cup rendered bison fat
  • 60.8 grams lye
  • 1/3 cup water
  • paprika added generously for color
  • ~ 1 teaspoon vanilla essential oil for scent
One cup of rendered bison fat from the bison we butchered.

I weighed the lye crystals on the coffee filter carefully using the electronic scale. Then I mixed them into the bowl with 1/3 cup of water on the right. The water and lye reacted chemically and heated up.

Meanwhile I melted the bison fat and started monitoring the temperature of both the fat and the lye mixture.

It took some jockeying to get both temperatures to drop to 98 degrees at the same time. I ended up chilling and reheating the fat, but eventually I zeroed in on the target temperature. Once the temperature of the fat and the lye were both around 98 degrees I poured the lye into the fat and mixed.

I stirred for about 10-15 minutes to fully mix the lye with the fat. As it cooled it started to thicken. Once a drip from the spoon lingered on the surface of the mixture I knew it was time to pour.

I quickly mixed in the paprika and vanilla oil and then poured it into a plastic mold.

I'm kind of surprised at how much the ingredients made. Now I will let these set up for 3-4 days. Then I will knock them out and let them cure for 3 weeks. Hopefully the final products will not burn me.

Wednesday, June 03, 2009

Bison Hide Tanning Part 2

Two weeks ago my brother and I made our first attempt at tanning the bison hide. We were given access to the TrackersNW facility so we were able to move the project from our apartment to a more adequate setting. We started Friday evening by cleaning the hair with shampoo and conditioner. As recommended on the bottle, we rinsed and repeated (about 8 times). When we finished we left it to dry overnight.

Saturday afternoon we took a short kayaking trip on which I capsized and got my brother's camera a little wet. As a result I wasn't able to get pictures of the tanning process which is a shame because they would have been good. Luckily, the camera is fine. After the trip we returned to the hide to apply the dressing. We mixed up soap, neat's foot oil and the bison's brain (a traditional tanning dressing) and spread it on the hide to soak in. We used a softening stick we made to push the dressing into the hide. A softening stick has a wide flat end so you can massage the hide with more surface area. We left the dressing on the hide overnight to give it more time to saturate.

Sunday morning we started the drying and stretching process. This is usually the most tedious part of the process because you have to continually stretch the hide until it is completely dry lest it become stiff. This can take many hours. The sheer size of the bison hide made this especially difficult. Luckily the weather was warm and we had sunlight to help speed up the process. We started by leaning the frame up against a tree. At this point the hide was still dripping with the dressing. We used the softening sticks we made to stretch the hide.

We were happy with how quickly the surface seemed to dry out. The hide got really stretchy and it took a lot of force to give it a full stretch. Eventually we laid the frame on 5 gallon buckets like a trampoline and used our body weight to fully stretch the hide. This is where it would have been nice to have some pictures. :( We took turns walking around on the hide. The hide stretched so much in the middle that it touched the ground and we had to raise the frame higher with some wood risers. We also rubbed it with pumice stones to soften it.

As the day wore on we realized that while the middle was fairly soft and stretchy, the sides were rather stiff. We decided to call it a day. We took it off the frame. The next morning the middle was still pretty soft. The rest was pliable, but still pretty stiff. For example, you could wrap it around you if you had to but you couldn't make clothes out of it. So that is the current state. We may try to tan it again, but we are afraid it might start to fall apart. We already lost some hair and put a few more holes in it while stretching it.

There are a few reasons why I think the sides may have been stiff. First, we may not have had enough dressing. When we left it overnight it settled in the center of the hide. Second, it was harder to stretch the sides because they are closer to the frame. On a trampoline the middle is where you get the most bounce. Next time I think we need to make sure the sides get saturated with dressing. Maybe we can loosen the hide in the frame so we can stretch the sides more.