Introduction: How to Make a Coffee Fire Log
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.
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!
84 Comments
10 years ago on Introduction
I found this alternative recipe in patent: A coffee ground-based fuel composition comprising of: (A) dried spent coffee grounds by 54% by weight; (B) vegetable shortening; by 23% by weight; (C) brown sugar by 20% by weight; and (D) corn syrup by 20%
Reply 5 years ago
That's 117%
Reply 1 year ago
I suspect they may be using a measuring system called bakers percentages. It measures by weight. All ingredients are in the same weight measurement(ie, ounces, pounds, grams, etc) and assigned a percentage based on the main ingredient. In this case, coffee grounds, would be the main ingredient and for the purposes of the recipe, is assigned a value of 100%. Let's say that we have 16 oz(1 lb) of ground coffee. The amount of each of the other ingredients is found by multiplying 16 oz by the percentages listed in the patent. So, here are the figures:
Vegetable Shortening 16 oz(amount of coffee grounds) x .23(percent listed above) = 3.68 oz, Brown Sugar 16 x .20 = 3.2 oz, corn syrup 16 x .20 = 3.2 oz. So, in our example the entire recipe would read 16 oz coffee grounds, 3.68 oz vegetable shortening, 3.2 oz brown sugar and 3.2 oz corn syrup. You would need a scale for this and I would actually recommend metric measurements for ease and accuracy.
Reply 1 year ago
Go big or go home.
Reply 5 years ago
I will try that. Thieve ideas are so neat.
Reply 10 years ago on Introduction
Very cool, thanks for adding this. I'll have to try it out.
Tip 2 years ago on Step 1
You can buy the wax at the grocery store or Wal Mart in the canning section. Waayy cheaper than the craft store...unless you havea coupon!
Reply 1 year ago
Also, check out thrift stores for candles!! Old Crayons might work as well.
Question 2 years ago on Introduction
Help! I made a trial run batch of coffee logs, intended for a friend's 40th this week, to go with the firepit she is getting. I followed the instructions here but my pan of coffee log mix once cooled, had a crust of wax on top. The coffee was slightly bound together but it looked like the wax had separated from the rest of the mix.
I had made sure that the wax and molasses were fully liquid before adding the coffee grounds.
What should I try next?
Thanks.
13 years ago on Step 3
What is the purpose of the molasses? Would it matter if I omit it, or do you have a suggested alternative? I would just rather make this out of all things that don't have another really practical use such as for eating.
Also, I would definitely suggest using old burned down candle stubs instead of fresh new candles or even newly purchased blocks of wax. That's just me though -- repurposer that I am. :).
Reply 3 years ago
it's not just that, the wasted energy used to melt the wax is certainly the opposite intent of reuse of the coffee grounds and wax, maybe if you had a solar oven to do the melting and possible coffee ground drying ?, then you could kill two birds with one stone, teach re use / re cycle and some type of solar energy component by constructing a cheap solar oven out of scraps of shiny metals for reflectors ( old mirrors, even aluminum foil taped to used cardboard or scraps of reflectix or a summer windshield car cover from the dollar store shaped to bounce the sun onto the container holding the wax should work .i.e. a used beat up thin walled black pot with a lid from a thrift store and probably a sheet of glass or plastic wrap to cover the top opening as a windbreak to keep the heat in). In a few hours on a sunny day you've got an upscaled oven melting wax for free that you could use for the project and in a pinch with a cleaner pot or even food in a zip lock freezer bag you could actually cook food in it like a slow cooker. But wasting energy to melt wax to make a fire log? other than the ambiance of the finished project why bother?.
Reply 3 years ago
How we start is different for everybody. Maybe this is the kind of thing that you would have melting next to your campfire, with coffee grounds from the week before drying out on rocks or wood planks or cast iron pans. I usually keep a tin can next to my stove/firepit where I collect my coffee grounds and food grease. Other food scraps can go elsewhere but these two when combined with wax and other additives can turn into instant fire with a flint, a wick, a spark from a 9v battery, or they can be wrapped up like a fire log. In this scenario it took no additional energy for me because the fire is already built. The coffee grounds already used and collected.
Reply 13 years ago on Introduction
molasses acts a binding agent with coffee grounds to keep the melting wax from just flowing all over the fire pit. As molasses is mostly sugar, it will harden as the fire burns, allowing briquettes to burn longer
3 years ago on Step 4
first - why are we using molasses? ah - found my answer from someone else. second, if you LINE your pan with parchment paper, wax paper or newspaper, you won't have difficulty taking the brick out and you can use this as your "starter" packaging. also liked the idea of filling milk cartons; can't wait to try it now that i'm drinking coffee
Reply 3 years ago
That's a great suggestion, thanks for adding it!
Question 4 years ago on Step 2
What does molasses do in this process?why will the log not burn if only wax and coffee grounds are added?
Question 4 years ago on Step 6
I melted wax using double boiler method & made a small log. When i tried to burn it using Bunsen burner only the wax used was getting melted. I am disappointed. What should i do?
Question 4 years ago on Step 2
Are these black strap molasses?
Reply 4 years ago
I used Brer Rabbit Molasses "Full Flavor". I'm not sure what the difference is.
15 years ago on Introduction
I bet waste glycerine from biodiesel production could be used here as well.