# Perfect Cup of Coffee

I read this article a few months ago and have had a project idea stuck in my head ever since. There is nothing like taking a sip of coffee and saying, "Holy crap, that's a good cup of coffee."

To summarize the article, a refractometer combined with an iPhone app can tell you if you have the "perfect" cup of coffee. What it does is measure the index of refraction of the light and displays information of the coffee in terms of extraction yield, total dissolved solids (TDS), dose weight, brew water weight, refractive index and temperature. "The perfect cup of coffee has a brew strength (or TDS) of 1.15-1.50 percent and an extraction rate of 18-22 percent." If you love coffee and are curious of the science behind it, the article is an interesting read.

Anyways, I was thinking it would be great to combine this technology into a coffee pot. The disadvantage of the refractometer and iPhone app is it is expensive and doesn't brew the perfect cup of coffee, it only checks if it is a perfect cup of coffee. So we would have a refractometer, or something to measure the index of refraction of the light, built into the coffee pot. Once the "perfect" POT of coffee has reached the required level, it will stop brewing the coffee and tell you it's ready for consumption.

First of all, any ideas how to make an inexpensive refractometer or something that would yield similar results? Also, what do you guys think of the project, is it something you are interested in? Any feedback will help, Thanks.

In my opinion, the perfect cup of coffee is an empty cup.

I suppose the tricky bit would be making your iPhone and sensor work at 15 bar (220psi).

In my opinion, the perfect cup of coffee is any that makes my finger tips tingle. 8)

AWOL:
I suppose the tricky bit would be making your iPhone and sensor work at 15 bar (220psi).

I might be missing something here, not being a coffee drinker, but the coffee make that I have that I use for tea, instead, would be in pieces all over the kitchen if it ever saw 220 psi.

AWOL:
I suppose the tricky bit would be making your iPhone and sensor work at 15 bar (220psi).

I don't want an iPhone to be apart of the project. I rather it display that information on an LCD. Cheaper and easier to program for those who wish to replicate it.

I love coffee

I might be missing something here, not being a coffee drinker, but the coffee make that I have that I use for tea, instead, would be in pieces all over the kitchen if it ever saw 220 psi.

The perfect cup of coffee comes from an espresso machine, which typically operates at ten to fifteen bar.

AWOL:

I might be missing something here, not being a coffee drinker, but the coffee make that I have that I use for tea, instead, would be in pieces all over the kitchen if it ever saw 220 psi.

The perfect cup of coffee comes from an espresso machine, which typically operates at ten to fifteen bar.

Indeed - there are hazards associated with this:

While on the subject I note that someone had a neat way to package coffee-related hardware a while back:

My question though is there a similar way to use an Arduino to make the perfect cup of tea? Or a wearable device to warn others of the level of caffeine in your bloodstream!