Hydrometers for Coffee

[oneday]

Hi guys,

just wondered if people would recommend buying a hydrometer. i am thinking it would be pretty useful feedback mechanism after brewing, and for calibrating the taste buds to the scaa brewing control chart.

is there any coffee-specific model? or, do any of the site sponsors stock them?

[blanyon]

Re: Hydrometers for Coffee

Just went and did a bit of reading and it sounds like you could just use a beer hydrometer and with a bit of trial and error develop a bit of an equivalent scale. However sounds very nerdy and the bits I have read about it seems to show that it doesnt relate very well to "whats in the cup" so IMHO not something I would be interested in. If you go down that path bring us along as I am sure we would all learn something.

[stuartgrant]

Re: Hydrometers for Coffee

In homebrewing, I find I need a sample of around 80-100mL to adequately fill the testing jar and get a reading... Might therefore need a smaller hydrometer? Or you could use a refractometer which only requires a drop - but costs a lot!

Espresso being colloidal, rather than a solution, I would have thought something that measures total dissolved solids would be of more use? Just a thought.

Cheers
Stuart.

[oneday]

Re: Hydrometers for Coffee

yeah, i believe the refractometer to be more suitable, though the cost is the impediment there i think. additionally, what scale to you use to measure total dissolved solids if using either a hydrometer or refractometer? brix scale was developed for expressing the ratio of sugar to water; is that sufficient for coffee?

[stuartgrant]

Re: Hydrometers for Coffee

Not sure. Theres plenty of sugar in roasted coffee (and therefore espresso), but the level of sugar has more to do with the level of roast than the quality of the espresso, Id reckon.

I reckon TDS correlates with viscosity fairly well. Im not sure what a good measure of viscosity is, but that might be a good starting point.

Of course, it would merely be (yet another) diagnostic tool and wouldnt necessarily give you much info unless you were could then link X units of viscosity in an espresso to the optimum taste (for that bean, at that roast, on that machine, using those variables...). But hey, it might be interesting!

Cheers
Stuart.

[Dimal]

Re: Hydrometers for Coffee

Quite respectable Refractometers can be had for ~$80 or so.... Not industrial quality but more than good enough for home use... 8-)

Mal.

[mwatt]

Re: Hydrometers for Coffee

If youve got a spare $1K ish, you could always get an ExtractMojo. George Howell has developed refractometers for brewed coffee as well as espresso, plus all the software that goes with it.

Wont post a link by google is pretty useful from what I hear

[Dimal]

Re: Hydrometers for Coffee

If youve got a spare $1K ish, you could always get an ExtractMojo. George Howell has developed refractometers for brewed coffee as well as espresso, plus all the software that goes with it.

Wont post a link by google is pretty useful from what I hear

Ill stick with using my Mass Spectrometer for this sort of thing

Mal.