In this instructable, I'll show you the basic recipe for making a Coffee Fire Log. The recipe could still use some tweaking, but it's a good start and a fun and easy project.
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Step 1: Gather Ingredients
From my searches on the web, there are three ingredients in a FireLog; coffee grounds, wax, and molasses.
I used a bread pan to combine all the ingredients and press the loaf.
I used candles, but you could use the blocks of wax they sell at craft stores (will try during next attempt).
Also, make sure the coffee grounds are completely dry. You can get the grounds free from any Starbucks. If they don't have any sitting out (for compost), then just ask. They are more than happy to get rid of them.
Step 2: Combine the Ingedients
I put two and a half candles and the molasses into the bread pan. I usually fill the bottom of the pan with a generous amount of molasses, but I ran low for this last batch.
Now we need to melt the wax. I put the pan in the oven (as pictured) at 260 degrees. I also put the coffee grounds, in a metal bowl, in with the pan to dry them more. It takes about 25 - 30 minutes for the wax to fully melt
Step 3: Add the Coffee Grounds
At this point the wax should be completely liquid and the molasses will have probably settled to the bottom. Stir it up a bit. I used a chopstick, but if you have cheap whisk you don't care about, it would probably work better.
As you can see in the second picture I start adding the grounds one scoop at a time. The wax may fizzle and bubble when you add the first scoop, like in picture 3. If it fizzles as much as shown it probably means you coffee grounds are still moist.
For this amount of wax and molasses, I used 5 heaping serving spoonfuls of grounds. The entire recipe can be doubled to produce a larger log (which I plan to try next).
You'll know your done stirring when all the grounds are dark and slightly glossy (Like in the 5th picture). Make sure you stir in all the corners (this is when the chopstick is handy).
Step 4: Form Your Log
The next step is to press to grounds in to a solid form. I used aluminum foil, but you could probably use wax paper or plastic wrap. I think for the next time I'll cut a block of wood to size and use that to get an even and firm push.
By this time the wax should have cooled down a lot, but make sure you test it first. If it's too hot to the touch, let it cool some more, you will still be able to mold it. Cover the pan with the aluminum foil and start to press down like in the first picture below. Make sure to get the corners as well. Once you feel you got it good enough (doesn't have to be perfect, after all you're just gonna burn it), you can let it dry overnight or you can throw it in the freezer for about an hour. You can see how far down mine went in pictures 2 and 3.
Step 5: Release Your Log
You final product should look nice and glossy like mine in picture one.
Use a knife and cut around the side of the pan to loosen up the log. You can either try to pry it out or turn the pan upside down and bang again the counter. I should look like picture 2.
Step 6: Burn Your Log
This is the fun part.
5 or 6 sheet of newspaper under the log should be enough to get that puppy fired up.
Now sit back and relax.
These logs don't last as long as the store bought ones, but I figure with enough people tinkering with the recipe we can get in mastered!