The easiest way to combat sourness is to increase the buffer content in your water.

And I say this knowing that some 25% EY can taste too citric on low buffer water.

I feel so dumb. But how do you know what your buffer content is?

Recent water report (average values):

9 ppm - Chloride
160 µS/cm - Specific Conductance
17 ppm - Sulphate
72 ppm - TDS
55 ppm - Alkalinity (as CaCO₃)
12 ppm - Calcium (as Ca)
252 ppb - Chlorate
45 ppm - Hardness as (CaCO₃)
4.0 ppm - Magnesium
9.3 - pH
0.8 ppm - Potassium
4.8 ppm - Silica
14 ppm - Sodium

Jonk wrote: Do you mean effective? Because that's pretty advanced if you ask me
Perhaps Rabh doesn't really need to adjust anything, but easy options would include changing the beans or perhaps use a different grinder (just expensive).

It really depends on what you mean by effective. I personally find that more developped roasts can mask the bean's flavours behind roast flavour, especially when you want to extract a lot.

Not to mention that you don't know in advance how a bean is going to taste, so you'd be taking risks every time you change beans.

And too often, a grinder that extracts more doesn't solve the acidity issue, all you're doing is ensuring that all the acids in the beans go into the cup, and that you have other compounds that balances it out. Same with higher temperature.

Then there's flow control, longer (duration) shots in theory extract more compounds that balance out the acidity, they taste chocolatier, but the acidity is still there. And there are some beans for which this does nothing at all wrt to acidity. And if you're doing this by grinding too fine, a nearly choke shot tastes horrible because the fineness of the grind means a very uneven extraction.

Admitedly a longer ratio absolutely works, you're diluting the drink, and there's more buffer in the espresso because you used more water.

And there's the bottom paper filter trick I wrote about a while ago that increases the evenness of extraction that also works to some extent.

But in all, recipe water is a systematic solution, control the amount of buffer in your brewing water.

jpender wrote:I feel so dumb. But how do you know what your buffer content is?

Recent water report (average values):

9 ppm - Chloride
160 µS/cm - Specific Conductance
17 ppm - Sulphate
72 ppm - TDS
55 ppm - Alkalinity (as CaCO₃)
12 ppm - Calcium (as Ca)
252 ppb - Chlorate
45 ppm - Hardness as (CaCO₃)
4.0 ppm - Magnesium
9.3 - pH
0.8 ppm - Potassium
4.8 ppm - Silica
14 ppm - Sodium

General hardness (GH) is 45 ppm as (CaCO₃)
Alcalinity or Carbonate Hardness (KH) is 55 ppm as (CaCO₃)

That's imho the right range for people who like a quite a bit of acidity in their filter roasts pulled as espressos. But I've seen other people bump it up to 120 KH, and alternatively I've gone down to 20 KH. Pham in this thread also, knows a lot more about water than I do.

Also quote from Jim Schulman's water faq

Finally, bottled waters mostly report their minerals as straight elemental mg/l or ppm rather than
mg/l CaCO3 equivalents. To get the alkalinity, multiply the bicarbonate by 0.82; to get hardness
multiply the calcium by 2.5, the magnesium by 4.2, and add the two. If the water is fizzy, and
bicarbonate level isn't stated; the alkalinity will equal the hardness after the water goes flat.

Interesting. I know water is important and also that it's a big, involved, and non-intuitive subject. It's really a different thread though. A whole sub-forum could be devoted to it. My water isn't perfect but I don't want things to be over complicated. One of the beauties of the Robot is how simple it is, how easy it is to work with, how fast. I lift it out of a cupboard each morning to use and set it back in there after I'm done. It weighs less than our Cuisinart. There's virtually no maintenance. And it produces really, really good coffee. Would it be substantially better if I mixed up jugs of special recipe water? I'd need a second kettle.


With regard to doses I'm confident that I could pull good shots at anywhere between 10 and 20g without a lot of fuss, at least with medium and darker roast coffees. But I think there is something to be said for being somewhere in the middle, in terms of both consistency and taste. At least that's my impression.

Interesting - I have ended up at around 16g for the Robot as well, partly because I dose around 15g for the Strietman and that works well too, so i sorta got used to the smaller.
Both are manual levers and more alike than you might think - at least to me, they react the same way. Might sound strange but it is just something with the way the pulls feel with the high doses that doesn't sit quite right with me. Some coffees want higher doses of course, like for instance maragogypes.
The Strietman filters do not have the inward slope, but then, they are 50 mm, not 58.

Is there a 58 mm filter with that slope available from IMS or the like? I think have only seen the straight ones.

jpender wrote:Interesting. I know water is important and also that it's a big, involved, and non-intuitive subject. It's really a different thread though. A whole sub-forum could be devoted to it. My water isn't perfect but I don't want things to be over complicated. One of the beauties of the Robot is how simple it is, how easy it is to work with, how fast. I lift it out of a cupboard each morning to use and set it back in there after I'm done. It weighs less than our Cuisinart. There's virtually no maintenance. And it produces really, really good coffee. Would it be substantially better if I mixed up jugs of special recipe water? I'd need a second kettle.


With regard to doses I'm confident that I could pull good shots at anywhere between 10 and 20g without a lot of fuss, at least with medium and darker roast coffees. But I think there is something to be said for being somewhere in the middle, in terms of both consistency and taste. At least that's my impression.

If what you posted is your water profile straight out the tap, count yourself lucky you are in pretty good shape. If you wanted to experiment with more alkalinity you could add some potassium bicarbonate or even just baking soda as an experiment, but you've got pretty good water to just use as is.

jpender wrote:I know water is important ... A whole sub-forum could be devoted to it.

Yes. there is a water subforum here on HB: /water/

Nate42 wrote:you've got pretty good water to just use as is.

+1. The usual advice re alkalinity for espresso machine water is to keep it above around 40 mg/L, and your water should be fine there.

P.S.
The term, "alkalinity", is the standard term to refer to the acid buffering capacity of water, although some coffee people seem to prefer the term "buffer" for that. When dealing with drop titration kits you often see "KH", "carbonate hardness", and "temporary hardness" used for kits that actually just measure alkalinity.

zix wrote:Is there a 58 mm filter with that slope available from IMS or the like? I think have only seen the straight ones.

E&B IMS Super Fine baskets have tapered bottom. They also have a unique additional metal filter at the bottom, kinda like putting an Aeropress filter like some people do.