Using cold coffee?

[chuck_n_grace]

Hi,
We recycle our coffee grounds into the compost bins. Grace uses them for the roses and some other plants.

How about the leftover coffee in the pot? Can it be used too? Applied directly to the soil around plants?

Regards,
Chuck

[frozenthunderbolt]

It may be good for blueberries as it is mildly acidic

[chuck_n_grace]

frozenthunderbolt,
That's what were thinking. We regularly have a couple of extra cups leftover each day. I would like to collect it and use it somehow. Our left side of the front garden is our 'acidic' bed so this just might work. I'll start tomorrow.

Thanks,
Chuck

[contadina]

Forget the garden and think granita Add sugar to the coffee, part freeze in a plastic bottle then shake, continue in this fashion until you have little coffee ice granules and store in the fridge (refreezing when necessary). Perfect for hot summer days.

[oldjerry]

Or open a bottle of Marsala,and make TIRAMASU......then invite me round....! Best Wishes.

[Glen Gilchrist]

You can extract up to 15% coffee oil from used coffee grounds (acetone extraction) -- evaporate off the acetone. The coffee oil can then be turned into really good bio diesel, or burned directly in a wicked lamp.

Smells lovely!!!

Glen

[wulf]

For non-chemists, how does that work? I am guessing that you pour on acetone, which dissolves the oils, pour off the resulting liquid and then gently heat in a well-ventilated place so that you are left with the oil?

Wulf

[Glen Gilchrist]

Yea....

The oil in any vegetive matter can be removed by either steam distillation ( better, but more complex), pressing ( works best for BIGGER items such as olives) or solvent extraction. Acetone is used as it has a low boiling point, so can be easily removed from the extracted oil.

1) Place coffee grounds ( wet is fine) in suitable container and cover with acetone until grounds ate just covered.
2) leave covered for as long as you can suffer. ( commercially, they will reflux the mix - boil and capture the acetone and reuse)
3) evaporate off the acetone ( into the air if you must). Ideally capture the acetone and reuse.
4) use the oil to make biodiesel (Or as an intense coffee flavor)

Might only work if you can get access to the right glassware.....

We did this with our sixth formers.

G

[The Riff-Raff Element]

One can by something called a Soxhlet extarctor, which is a set of chemist's glassware used for the highly efficient recovery of organic chemicals via a continual recycling of solvent. It's good old bucket chemistry!

Amazon in the US sell them and they should be pretty easily available elsewhere. Couple this with a simple still to recover the solvent (and for Heaven's sake use a proper heater designed for flamable liquids) and you'd be in buisness. You could extract all kinds of stuff. The globe would be your mollusc.

http://www.amazon.com/gp/product/B003NU ... HX63R0KX6T

[dave45]

It looks great fun, but the kit seems a smidge expensive!

[dave45]

btw what is the boiling point of acetone, and where can you get it cheaply in quantity?

or can you make it out of leftovers?
:-)

[Glen Gilchrist]

Acetone boils at 56'c - generally available in chemical Catalogues. Not proscribed or on dodgy lists. If you just want coffee "flavour" use vodka instead...... Then you can just add it straight away...

G

[The Riff-Raff Element]

It looks great fun, but the kit seems a smidge expensive!

An investment, certainly, but quite often this kind of kit comes up on ebay and so on and can go pretty cheap.

[Mrs H]

Ok so am I being a bit blonde here?!? R u trying to say that I can recycle my coffee grounds and use it to run my landrover? X

[Glen Gilchrist]

Yes - in a nutshell.

Coffee grounds (used) are about 15% coffee oil, which can be processed really easily into biodiesel. Most diesel engines can use biodiesel without modification and people arguee that its clear / better for the engine than fossil diesel.

Google "bio diesel"

Essentially you mix the oil (use cooking oil, coffee oil etc) with a mixture of sodium hydroxide (lye from soap making) and methanal and it reacts to make biodiesel and some glycerol (can be used to make soap later).

We (as a school) are currently swapping emails with Cafe Nero to try this on a large-ish scale...

Cheers
G