hello all.

A while back I asked in the coffee forum for recommendations on blends that will have absolutely no sourness, as the few bags I bought from mountain air roasting all tastes sour, even when they are explicitly tagged as dark roast and from central america region (rather than the africa region). My understanding (very likely to be wrong) is that dark roasted coffee and coffee from central america will be less sour than light roasted/africa region. With that being said, all my coffee taste very sour and I think it has nothing to do with the coffee but my technique (french press)

From some of the readings I did I have seen

22g/300g ratio
skim off the top bubbly portion right before plunging
4 minute brew time with 1 of the minutes used to bloom
stir/don't stir grounds during blooming
coarse grind.

I have done all of those and they all taste sour. I use vario with ceramic burr setting at 10Z (the coarsest setting possible) and results weren't any better. I'm still convinced it's my technique and I don't want to blame it on the grinder or the coffee but I don't know what I'm doing wrong.

Thank you for your pointers.

Sounds like you are too coarse. Grind finer, more like a fine/medium-fine drip grind.

There's not really any need to bloom, try to get all the coffee wet as early & evenly as you can. Dunk more than stir.

Don't disturb the pot after you have started steeping.

You can go over 4 mins. Skim/pour off the surface layer then taste, if it's still sour, leave it longer (keep the lid on, otherwise you'll keep dropping the heat & the whole process will take longer).

Thank you Mark

Prior to this last cup I was on 8R for the setting while everything else is the same (4min steep, 1min blooming. same ratio) and it is just as sour. I have tried the higher end of 8 for macro and It got a little too fine that when I depress the plunger there was a lot of resistance. I bought a bag of peet's major dickson whole bean and used the same method and ratio and it came out to be not sour. Could it be that freshly roasted beans are all sour while old beans like peet's in supermarket are just...not sour?

Old beans will extract more easily, more recently roasted & lighter beans will take longer to extract & may more prone to producing sour brews, but "beans" themselves aren't sour unless you have some sort of serious defect, only the coffee you (or I) make will be sour, normally due to underextraction. When you extract any of them satisfactorily the sweetness will come.

I don't plunge my French presses (after reading one of James Hoffmann's blog posts), plunging can cause smaller particles to be flushed through the mesh into the beverage, if you grind reasonably fine, leave the brew long enough for the grinds to sink & pour the coffee through the mesh held above the brew, you shouldn't get particularly heavy silt (I hate silt in French press brews, using this method & watching the pour, in one motion carefully, I rarely get more than a light dust in the bottom of the cup).

How is your water temp? For small, glass presses I preheat, but for larger & double walled presses I don't bother...in fact my double walled steel press can be on the hot side if adding the water 30s off boil. I also add the water first, then coffee (when at ~92-94C)...this helps with the clarity, but can slow the process down a tad...so if time is a concern carry on with coffee first.

I see.

I don't pre-heat my press and I believe I should do so.

My press is glass with metal mesh filter and I bring my filtered water to a boil (not violent rolling boil) and i leave it on the counter for 30 secs before pouring. I will try with water first then coffee. I will also let it steep for 6 minutes this time so see if it'll help with extraction. How likely is it for this sourness to be contributed by vario (which is not so great for coarse grind)?

If freshly roasted coffee are better in terms of flavor but sourness is inevitable I assume I can get by that by steeping longer? The thought of using a vario just for peet's beans is a little depressing...haha

I think it is very unlikely indeed that the grinder is responsible for sourness, it is much more likely that an overly coarse grind setting is the culprit.

Sourness is more likely with recently roasted coffee, rather than inevitable (I've had sweet FP brews at 24hrs past roast, grinding very fine & then filtering), yes, steeping longer (& grinding finer) will help. If you start getting to much sediment in the cup you might also try filtering via an Aeropress, or Melitta style cone with a white Filtropa paper?

If you like to drink your coffee really hot, then that might limit the time that you want it to steep, but a lot of folk might still find it too hot to drink after 4-6minutes, so if you are waiting for it to cool, you may as well let it cool in the press (to push on extraction, get past the sourness) rather than cool in the cup (when extraction has been halted)? E.g. I have a plunger that fits a few presses, so I unscrew the knob at the top, this means that I can stick a temp probe down the hole in the press's lid & kill the brew at a desired temp (though normally by time & tasting), lift out the probe, place the mesh in the pot, lid back on for tasting/decanting.

Thank you.

I will try with a finer setting and 6-8 minutes steep time tomorrow. Will report back!

Hi Wynn,

The illustration on the back of the bag depicts the correct grind size, to scale. Sprinkle some grinds on the bag for reference. For french press, follow the ratio listed beside the french press icon. Otherwise, MWJB is dead on for correct technique. I suggest water directly off the boil, at least to start. You'll get a very well balanced, mostly chocolaty cup.

Hi Marshall

I shall give the ratio on the back a try tomorrow. I'm starting to think I'm just ultra sensitive to the sour taste and it's not the problem of the beans nor the equipment. With that being said I've never had a cup of good press coffee to compare it with. Maybe I should bring a bag of beans to a local coffee shop and have them make it and see if it tastes the same as at home.

I'm still trying to find the good grind size sweet spot but it's hard. Back of bag says 800micronmeter and I have no idea what that translates onto my vario. Should I be getting some resistance (but not so much it's impossible to push down) with the correct grind size?

AH! Don't push the grinds down with the screen. After pouring, let the brew sit for two minutes, then dunk the grounds gently with a spoon. Enjoy the aroma that comes up on doing so. Let the brew settle another minute or two before pressing. There should be no resistance.

800um is exactly the size of the dots shown on the bag. Match your grind size to those; this is your starting point.