Acidic flavours

[Bames]

Hey all,
What, besides the beans themselves, will contribute to more acidic flavors in the cup? Both on the baristas technique as well as the machine/grinder - but more on the baristas technique and skill (or lack of skill!).
Cheers!

[Andy]

Re: Acidic flavours

Acidic, sour or bitter?
tis always tricky determining what someone else is tasting via a webpage.

Short answer in rough order is:
Bean
Roast
Grind
Water Temperature
Dose
Machine cleanness

...all of it really!

To determine which is causing the problem you need to change a lot of variables one at a time and there is no "one size fits all" answer.

A good level of acidity is rarely bad and in most milk based coffees some acidity is mostly a good thing but sour is rarely good.

Confused?  Think Coke Cola for acidic, you can feel the acid on your teeth but it doesnt taste sour like citrus (even with coke levels of sugar) and for bitter think panadol dissolved in your mouth.  Grapefruit would be bitter/sour.

[sidewayss]

Re: Acidic flavours

I find that theres more acidity from roasts that are done quickly in a fluid bed roaster like my coretto, which is a bread maker with a heat gun as a heat source.

Getting less acidity from my other roaster which is the FZ-RR700 Baby Roaster which works on the drum principle, even though the roast times are less due to the smaller batch size.

I,m dont know how to explain the science or chemistry behind all that.

The acidity of the corretto roast does suit it better for white coffee, whereas i enjoy the espressos coming from the Baby, though still also great in whites.

Sour and bitterness would result from user/barista input and/or machine and grinder factor.

Sour from under-extraction. Shots running too fast, so water not given enough time to extract the goodness from the bean.

Bitterness resulting from over-extraction. Hot water spending too much time in contact with the coffee, stripping off the initial goodness and then the less desirable bitter compounds.

Gary at G

[Andy]

Re: Acidic flavours

Im only slightly off topic and only slightly nit-picking but If I let it go to the keeper it might stick...

in a fluid bed roaster like my coretto

I dont think a breadmaker is "fluid bed" its a "teflon bed"

The term fluid bed isnt about using convection air, its more about suspending the beans on a bed of heated air.

So your breadmaker is a small percentage of conductive heat (from the contact with the pan) and a large amount of convective heat from gun. If anything a corretto would be a convection roaster.

Your baby roaster is nearly entirely conductive.

...and commercial drum roasters (due to the heavier drum materials) are a mixture of radiant, convective and conductive heat. The balance of which is mostly determined by design and the combination of air flow vs heat application.

Sour and bitterness would result from user/barista input and/or machine and grinder factor.

...or under roasted (sour) over roasted (bitter).

Sour from under-extraction.

Huh?
When next on the machine grind and dose a "known good coffee" as you would normally for a 30 second shot. Start the shot and stop it after 10 seconds and taste it. Let me know if you get sour.

Bitterness resulting from over-extraction

...and from over roasting.

Sorry to pick on your post Gary but there are lots of things in there I dont agree with.

With any luck JB can also be more specific about the scenario and we can determine what the problem might be.

[sidewayss]

Re: Acidic flavours

OT. My oops due to mis-information.

I stand corrected and thanks for setting it straight Andy.

Have been known for getting it wrong at times.
Even though i try to contribute as best i can to help others, i can expect feedback from others who will set the record straight.

Gary at G

[fractalsonfire]

Re: Acidic flavours

On the topic of sour tasting coffees, i find beans (when they give the description) having the citrus note characteristic to be a touch sour and tends to tingle on my tongue. This obviously annoys me and its further compounded when the bean has a nice body and flavour to it yet is ruined by the sour flavour.

How anyone can enjoy a sour coffee is beyond me.

EDIT: I should clarify that its not purely sour but rather you can taste it being sour with a mix of coffee flavour.

[alfadrian_syah]

Re: Acidic flavours

tentang topik biji kopi,
rasa asam bisa disebabkan oleh fermentasi yang terlalu lama pada proses basah. Kasus pada kopi sumatera, Normalnya fermentasi dilakukan 14-26 jam tergantung suhu air. Bila fermentasi dilakukan terlalu lama (>48 jam) maka rasa asamnya akan meningkat....akibatnya kopi terlalu asam....
Jadi penting bagi kita untuk mengetahui tiap proses dan lamanya masing-masing proses pengolahan biji kopi hingga menjadi biji hijau.

Namun apakah proses pengeringan yang terlalu lama setelah fermentasi dan pencucian juga berpengaruh terhadap derajat keasaman tadi....???  :-?


Translation from Indonesian using Google...:
about the topic of coffee beans,
the acetic acid fermentation can be caused by a too long in a wet process. Case in Sumatran coffee, normally 14-26 hours depending on fermentation carried out in water temperature. When the fermentation is done too long (> 48 hours) then it will increase its acid flavor of coffee is too acidic as a result .... ....
So its important for us to know the duration of each process and each of the processing of coffee beans to a green bean.

However, if the drying process is too long after fermentation and leaching also affects the degree of acidity was ....??? : -?

[ddthiel]

Re: Acidic flavours

Can I clean up that translation? Hope this helps

Regarding the topic of coffee beans:
A sour flavour can be caused by an overly long fermentation when wet-processing [the beans]. For example: Sumatran coffee. Normally, the fermentation process takes 14-26 hours, depending on the temperature of the water. If the fementation process is extended too long ( >48 hrs), then the sourness will increase, resulting in a coffee that tastes too sour...

So its important for us to know every process and the duration of each of these processes in the production of green coffee beans from the cherries.

However, [I have a question]: Does an over-long drying process after fermentation and washing of the beans also influence the aforementioned level of acidity?