Acidity Development in Roasted Beans

[DesigningByCoffee]

Hey all
Just an interesting finding - wondering if anyone has experienced this too.

Seems like no matter what kind of beans or what profile I use, following roasting the acidity within the beans seems to increase from virtually nil straight after roasting to its peak around 5-7 days, then tail off heading post 10 day mark. I'm not talking 'Melbourne Pucker Face' acidity, but good drinking, back of the throat acidity & zing.

Not a bad thing by any stretch, but I'd have thought that acidity would have started high with the fresh roast, then slowly decline over time…
Anyone else noticed / experienced this?

Cheers Matt

[Dimal]

That's probably close to what I've noticed over the years Matt...

Depending on the beans, roast depth, etc it varies a bit but what you describe seems to be on the money...

Mal.

[monarodan]

It's funny, I often say to my partner, "do you get that bit of heat in the back of the throat", to which she always says, "Ummm.... nope." Sometimes I wonder if I'm imagining it, but I'm sure it's there and it usually comes in some 5 or 6 days post roast and disappears a few days later. Is that what you mean? I get this from darker roasts with beans that give you a lot of cocoa. I must say, I like it and wish I knew how to make it more prominent.

Cheers,

Dan

[nescafeGOLD]

i was going to talk about CO2 and carbonic acid, then a quick google search resulted in a excellent analysis.

Storage of Roasted Coffee Beans to Maximize Flavor - Home-Barista.com

(not sure if were allowed to link to other forums on here so if tihs is out of line im happy for mods to delete).

[nescafeGOLD]

The water used will also affect the final pH of the brew (deionised water has virtually no buffering capacity so will tend to result in a lower pH due to the effect of carbonic acid where as tap water (which usually has a pH buffer) will not be as affected pH wise by carbonic acid (its pH will not alter as much)

[DesigningByCoffee]

It's funny, I often say to my partner, "do you get that bit of heat in the back of the throat", to which she always says, "Ummm.... nope." Sometimes I wonder if I'm imagining it, but I'm sure it's there and it usually comes in some 5 or 6 days post roast and disappears a few days later. Is that what you mean? I get this from darker roasts with beans that give you a lot of cocoa. I must say, I like it and wish I knew how to make it more prominent.

Cheers,

Dan

Hi Dan
Does sound like the same thing

I tend to find it builds like this in most beans and in most roast depths - almost independent of the sourness/flatness that can be caused but roast length or depth.
If you like this type of zing, I've found that you can build it up by shortening the time between 1C and 2C a little (i've been playing around with this zone seeing Mal's profiles ) but I then often have to offset this shorten roast time overall by slowing the ramp to 1C to prevent sourness…

Cheers Matt