Posted Tue Jul 3, 2012, 7:52pm Subject: Weird things I've done lately with coffee:
Investigation #1
I obtained some 75.5% ethanol (Everclear grain alcohol) - mostly to attempt a lipid extraction on brewed coffee with it. I just couldn't resist attempting to brew some coffee with it.
As some may or may not know, ethanol is a decent solvent for lipids (fats), whereas water... is not. When we brew coffee, the hot water emulsifies oils from the coffee - in brew methods like espresso and even the moka pot, the oils are physically forced out of the coffee under pressure. In methods like cowboy coffee (decoction), turkish, and contact methods where the coffee is drawn from the top (like Eva Solo or Press Pot), the oils are liberated from the grounds and being lighter end up partially emulsified and in the cup. A paper filter is both lipophilic and hydrophilic (i.e. it absorbs both fats/oils and water), and can remove some of the lipids from coffee. The majority of lipid removal is with methods where the coffee passes through grounds under gravity - the grounds tend to retain lipids in all but the lower layer of the spent grounds.
So, curious me wondered what happens if I brew coffee with a good lipid solvent?
And... now I have throat burning, sinus clearing, college-binge-drinking essence of overextracted coffee. ROFLOL! And my AeroPress is REALLY squeaky clean.
I brewed it cold, mostly for safety. Ethanol vapor is flammable, you know. I can't use the refractometer to measure strength - it's totally not calibrated for that. Ethyl alcohol has nD ~ 1.36, or in the 20°Bx range (20% sugar, or in approximate coffee terms somewhere around 15% strength) the VST only goes up to 20% espresso, so I didn't even bother. Even at a low concentration, ethanol will basically take any refractometer measurement and make it worthless.
Grind was very fine, contact time was 12 minutes.
This first result is strangely exotic, full flavored, with amazing body and is literally intoxicating. I'm not kidding, I can only take the smallest sips to sample taste.
What's left on the tongue, however, is pretty darn strong. Coffee-wise. I'd swear it's overextracted. Bitter on the tongue, and a very definite smokey-burnt aroma.
Never one to rest, I took the ethanol saturated grounds, and re-brewed them with hot water. I wanted to see what's left.
Now I have a 2nd cup of something that tastes pretty amazing. I liken it to a very mild, unsweetened Kaluha. Not bitter, sweetness shining through. Coffee with a good shot of alcohol.
I figure I'll try heating it up in the morning - that should flash some more of the alcohol out of it.
Just for kicks, I took 5ml of the first etOH brew (the full Monty first brew), put it in a dish, and placed the dish on top of another small dish with just-boiled water in it. I wanted to gently heat a thin sample, and see if I could reconstitute it with hot distilled water, and if I did, what would I end up with?
In about 20 minutes, the alcohol had evaporated, the bottom of the dish had some dried very sticky stuff not unlike what is left behind when I do home dehydration. I added ~5ml of hot distilled water, and to my surprise, not all of it reconstituted. Lots of it did - that stuff tasted like extremely strong and off-flavor coffee with overextracted bitter tones, but there were bits of undissolved stuff in the bottom, very heavy. When pushed around with a stirrer, it had the consistency of small flecks of tar. Very weird.
I finished the stuff that would dissolve - then of course tasted the flecks.
And yep - I had tasted this before. This is the nasty stuff that is at the top of a centrifuged espresso sample. Very thick and NASTY tasting "coffee oil/wax/tar" or whatever it is.
So, interesting. Not sure what tomorrow's rebrew will taste like... :^D
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Tue Jul 3, 2012, 9:04pm Subject: Re: Weird things I've done lately with coffee:
Interesting thing #2:
I took 8% brew ratio of unground coffee beans, (20g : 250g) added them to room temperature water, and threw them....
...into a blender. For 6 minutes. This is not unheard of - chat with some "natural medicine" practitioners, wet maceration is one of the traditional ways to make tinctures and extracts (tho usually with oils or alcohol, not water).
Then, the slurry went into my AeroPress, and I slowly pressed the coffee.
What I got was unlike anything I've ever seen.
Color and consistency is the same as if I put creamer into the coffee. Light tan, opaque emulsification. Really silky body, and the taste is like sweetened coffee with cream. Makes me shake my head thinking about it. It's in the fridge now to be sampled in the morning.
The process chopped the majority of the grounds to approximate consistency of turkish grind - very small particles and lots of fine near-talc.
I tried sampling the strength, but I suspect this emulsification is just not right. I used one of my few remaining VST filters - it plugged after about 1.5ml, and even then it was still opaque and same color coming out of the filter. It's putting the strength (with large amounts of variation) between 1.8 and 2.1% strength.
So... I dragged out the centrifuge.
10 minutes at max, and all I get is a slightly lighter creamy floating layer, the teeniest amount of fines in the tip of the tube, and the rest: basically unchanged. Same color, same opacity.
Cooled it in fridge, tried 20 minutes on max in centrifuge - just clarified the floating layer but no change to appearance. Tried heating a small sample - no dice, same thing, same appearance, and a tenfold increase in aroma!
Whatever has happened, this is an emsulsification as strong as mayonnaise with mustard added. It's unseparable as far as I can tell - a suspension that refuses to separate.
Taste is amazing, can't wait to heat it up and try it hot.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Tue Jul 3, 2012, 11:44pm Subject: Re: Weird things I've done lately with coffee:
If you feel like experimenting on something I've been enjoying but haven't found anyone else willing to try ....
I have been pulling espresso shots with a thin layer of raw sugar sprinkled on top of the coffee puck after tamping (not moist brown sugar, but that coarse textured and light brown color sugar - "Sugar in the Raw" is one brand). The result is very different from pulling the same shot without the sugar and then adding the sugar afterwards.
My theory is that the sugar dissolving into the water before the water hits the coffee changes the way the water reacts to the coffee particles and extracts the coffee more gently (or perhaps extracts certain components less or slower than others).
Cooking experts tell me that when you boil beans in sugar water they don't get "mushy" the way they do if you boil them in plain water. They claim this is because the sugar water doesn't "explode" or "rupture" the cells in the beans the way plain water does. Not sure of the science - but I sure taste and feel a big difference. (mouthfeel is the most noticeable improvement pulling espresso this way)
Posted Wed Jul 4, 2012, 9:44am Subject: Re: Weird things I've done lately with coffee:
AndyPanda Said:
I have been pulling espresso shots with a thin layer of raw sugar sprinkled on top of the coffee puck after tamping (not moist brown sugar, but that coarse textured and light brown color sugar - "Sugar in the Raw" is one brand). The result is very different from pulling the same shot without the sugar and then adding the sugar afterwards.
One of the videos I watched this morning had a lady putting raw sugar on top of the grounds in her espresso machine. I thought, so...using a moka pot, the sugar would go in first, then the coffee on top? I may try that tomorrow.
Boy, that other stuff sounds like mad scientist stuff!
archi Senior Member Joined: 4 Jun 2010 Posts: 101 Location: Redding, Ca Expertise: I like coffee
Espresso: In between Grinder: Zassenhaus hand mill,... Vac Pot: Yama 5 cup Drip: CCD v60 Roaster: Bread machine/heat gun
Posted Fri Jul 6, 2012, 1:01pm Subject: Re: Weird things I've done lately with coffee:
I am definitely going to try #2... Though I have to borrow my friend's aeropress first. I just have to see it for myself. It just doesn't make any sense.
No, I don't, but it will probably now go on my Amazon wish list! LOL
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Jul 9, 2012, 5:04am Subject: Re: Weird things I've done lately with coffee:
#2 - the emulsification trial:
Wonderful cup of coffee that his reminiscent of cafe au lait with an overlay of gently roasted coffee grounds. Aroma was quite fascinating - that's just with Eight o Clock Colombia. I will be trying it again at some point with a Uganda, Ethiopia or some other of the African varietals.
I still have a sample of it - after a week it remains emulsified. The only thing that's been successful at separating SOME of it is adding 2ml of the coffee emulsification to 2ml of ethanol (75.5%), agitating, then adding 2ml of distilled water after 3 minutes.
Usually, this is a quick makeshift test for presence of lipids. It is supposed to produce a floating layer of cloudy solution as the ethanol (an organic solvent) dissolves the lipids. Adding the distilled water causes the alcohol dissolved lipids to come out of solution.
However, all this did for the emulsion sample is create a less-cloudy solution with some HEAVIER gunk that has settled somewhere near the bottom of the tube.
I'll give it a spin when I get a chance, but it's been pretty.... interesting.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Jul 9, 2012, 9:15am Subject: Re: Weird things I've done lately with coffee:
archi Said:
I am definitely going to try #2... Though I have to borrow my friend's aeropress first. I just have to see it for myself. It just doesn't make any sense.
I want to try this too! We have a drink blender (Magic Bullet) for smoothies and such that should do nicely. And, I have the SS coava disk for my aeropress. The first thing I thought of for an aromatic emulsion of coffee would be to spread it on things for breakfast! I am sure more creative minds can think of other food uses.
Another idea that occurs is that it might make marvelous flavoring for ice cream... or dressings... or [sky's the limit].
Netphilosopher, keep up the coffee mad scientist exploration! We dilettantes will try to follow along.
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