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Java logs are a great product. They use spent coffee grounds and don't require trees to be cut for firewood. According to numerous web resources they also emit less greenhouse gases than burning wood.
This project is designed to not only use spent coffee grounds but the "disposable" cups we use to have our coffee on the go. As an added bonus it also uses left over candle wax from spent candles and you can even make it in the cup in your microwave with minimal fuss and mess. You can even re-use wooden coffee stir sticks or chopsticks.
This first attempt took about ten minutes to make. I let it cool for about half an hour before I lit it.
The documentation is from a proof of concept experiment that worked well on the first attempt!
This project is designed to not only use spent coffee grounds but the "disposable" cups we use to have our coffee on the go. As an added bonus it also uses left over candle wax from spent candles and you can even make it in the cup in your microwave with minimal fuss and mess. You can even re-use wooden coffee stir sticks or chopsticks.
This first attempt took about ten minutes to make. I let it cool for about half an hour before I lit it.
The documentation is from a proof of concept experiment that worked well on the first attempt!
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Signing UpStep 1The Materials And Tools
You will need:
A used coffee cup (Rinsed and dried or even just dried)
Spent coffee grounds, enough to fill a little more than half the cup
Wax, enough to fill about half of the cup, maybe less (It can be from any source, old candles, sealing wax, whatever)
Molasses, a few table spoons worked for me. I suspect brown sugar would also work but didn't try it. (I used unsulphured)
A knife to chop the wax
A microwave (This shouldn't damage the microwave so proceed without fear)
Optional materials:
A stir stick (I used a bamboo skewer but you could use anything you don't mind covering in wax and coffee grounds)
A sheet of printer paper, newspaper, a page from an old phone book, any non-glossy paper
The plastic lid from the cup. I used this for mixing and later to keep the java log from making a mess but it's totally optional.
Notes on getting the materials:
The cup
I used a basic white 12oz cup. You could use any size that's handy and will fit in your microwave.
Coffee grounds
I got my coffee grounds from a coffee shop. Most coffee shops will happily give you more than you can use. Some shops even set out grounds pre-bagged and ready to go so customers can use it in their gardens. You could use grounds from home. It doesn't matter as long as they are dry.
Espresso grounds from a coffee shop will be pretty dry when you get them. The ones I got were dry enough that I didn't have to bake them or anything before I used them.
Wax
I used leftover wax from a scented candle. I'd recommend using non-scented but just use whatever is laying around.
Molasses
I just used some we had in the cupboard. It's cheap and should be the the only material you need to buy. Though I suspect you could use sugar.
There is almost no cost involved in this project.
A used coffee cup (Rinsed and dried or even just dried)
Spent coffee grounds, enough to fill a little more than half the cup
Wax, enough to fill about half of the cup, maybe less (It can be from any source, old candles, sealing wax, whatever)
Molasses, a few table spoons worked for me. I suspect brown sugar would also work but didn't try it. (I used unsulphured)
A knife to chop the wax
A microwave (This shouldn't damage the microwave so proceed without fear)
Optional materials:
A stir stick (I used a bamboo skewer but you could use anything you don't mind covering in wax and coffee grounds)
A sheet of printer paper, newspaper, a page from an old phone book, any non-glossy paper
The plastic lid from the cup. I used this for mixing and later to keep the java log from making a mess but it's totally optional.
Notes on getting the materials:
The cup
I used a basic white 12oz cup. You could use any size that's handy and will fit in your microwave.
Coffee grounds
I got my coffee grounds from a coffee shop. Most coffee shops will happily give you more than you can use. Some shops even set out grounds pre-bagged and ready to go so customers can use it in their gardens. You could use grounds from home. It doesn't matter as long as they are dry.
Espresso grounds from a coffee shop will be pretty dry when you get them. The ones I got were dry enough that I didn't have to bake them or anything before I used them.
Wax
I used leftover wax from a scented candle. I'd recommend using non-scented but just use whatever is laying around.
Molasses
I just used some we had in the cupboard. It's cheap and should be the the only material you need to buy. Though I suspect you could use sugar.
There is almost no cost involved in this project.
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Best way to melt wax is in a "double boiler"; 1 pot with water, 1 pot inside that pot with the wax in it. Heat up the water pot and then put the 2nd pot with the wax in it in the water until it melts. That will ensure you never get a wax fire or have anything nasty happen in your microwave.
The web is full of advice, mainly from hobbyists, about how to heat or not heat wax.
Pay attention and you'll be fine. Wax only needs to reach about 150F to melt nicely. That happens quickly in a microwave. The flash point of most wax is just under 400F. That's a wide margin for error. Same as popcorn, don't set the microwave for ten minutes and walk away.
...however, in the interests of science! I'll put the word out for a sacrificial microwave and find out just how long it takes to spark a wax fire and then post my findings here. We have a firefighter in the family who will act as our pyrotechnical and safety consultant.
Whatever method you use, don't get it overly hot and pay attention to what you are doing. It's wax, it burns, you are using heat hot enough to burn your skin or scald yourself... or even start a house fire.
...and don't take everything you read on the internet at face value. Including this! Do your homework, test some things and find your own vetted experts.
If someone else does the microwave test before I do, let me know how it goes! That doesn't mean, tell what you read or heard. I want repeatable results! :)
The double boiler method is very stable and controllable, but likely would be better used if you're making several of these coffee fire cups rather than just one. Also, use a pot you don't mind getting wax all over - the stuff is a pain to clean out of a good one!
All the same, I like the *able, gives me something to do with those grounds I generate every morning.
Good point on the larger batches!
It also makes you look bad to the date you are trying to impress with your DIY Java log.