What's a good ppm alkalinity level for coffee brewing water?

[Silver_Is_Money]

Can you post grams per gallon of minerals for treated water? I’d like to check if I get similar results. I get 4ppm out of my RO

Mineral quantities are listed within the post you quoted.

 

[Silver_Is_Money]

I'm back to 11 being the correct pH for 4 gallons of RO water with 0.57 grams of added calcium hydroxide. Please ignore any of my posts to the contrary within this thread. And 1.3 grams of Baking Soda added to 4 gallons of RO water results in a pH of 8.27. See this online calculator for verification with respect to both minerals: http://www.aqion.onl/reacs/new/232404

Despite the vast disparity in these two minerals resulting water pH's, their alkalinities are equivalent.

 

[bierhaus15]

I've futzed around with coffee water chem for a few years now and have my water dialed in for the coffees I prefer; lightly roasted and high acidity Africans, lactics, and S. American stuff like Geshas. Kalita and V60 pourovers. I also make a pretty good espresso on my Flair, but it can be inconsistent. That said, I generally try to keep alkalinity below 60 and limit the amount of sodium and chlorides in my water. Generally, higher ALK can be overcome by increased Ca/Mg extraction and S04. Some general findings:

Ca - heavier, creamier mouthfeel, can be dry/earthy in high amounts
Mg - crisp, smooth, highlights fruitier character
Na - bitter, flat character > 20 ppm
Cl - sharp, dull, bitter above 30 ppm
S04 - crisp, bright, dry, fruity

The principle ions for coffee extraction are Ca and Mg, although too much of either are not ideal. Sweet spot for calcium hardness for my process is around 45, and I prefer more Mg/S04 to accentuate sweet-high acidity flavors; berry, tropical fruit, ect. For darker roasts and French-Italian style espresso, I've found the opposite to be ideal; higher Ca, Cl, Bicarb for improved body and reduced acidity.

My general profile for balanced, medium-acidity coffee with good mouthfeel is:

Ca-19, Mg-29, Na-11, S04-113, Cl-16, Bicarb-58, ALK-45

All said, water does amazing things for coffee, but it won't make badly brewed or roasted coffee that much better... and grind consistency is still key.

 

[Buckeye_Hydro]

Our commercial coffee customers typically shoot for about 50 ppm TDS for coffee brewing water. An inline calcite filter is sometimes used as well.

 

[mabrungard]

Russ, what are they adding typically to achieve that TDS? There are many ways to raise TDS.

 

[Buckeye_Hydro]

What I see most often is use of a blending valve that mixes permeate with de-chlorinated feedwater. Can be custom blended to a desired end TDS with use of an inline TDS meter.

 

[The_Bishop]

New morning, new test. This time I've mineralized 4 gallons of our under the sink RO with 1 gram each of CaCl2, CaSO4, MgSO4, and baking soda. By cutting the baking soda from 1.3 grams to 1.0 grams I'm attempting to compensate for the alkalinity present within our homes mediocre RO water vs. high quality Clearwater Systems RO water.

I'd like to thank you for posting this. I've been screwing around with building water for coffee for a while, and getting somewhat frustrated. I was dosing my RO water (4 TDS) very simply with CaCl and Sodium Bicarb, as I figured that the chloride would give the coffee that full/round flavor. However, the mix noted here has really transformed the cup. Been brewing a cup at a time with an aeropress inverted. One of these days I need to upgrade my grinder, but I'm having a hard time justifying the cost when my capresso infinity has been working so well.

 

[The_Bishop]

In the spirit of further experimentation, I decided to come up with a slightly different profile.

In one gallon of RO water with a 4 TDS reading:
.25g Gypsum
.20g Calcium Chloride
.25g Magnesium Chloride
.3g Baking Soda

Ends up with a water profile of:
Calcium:34 Magnesium:8 Sodium:11 Sulfate:37 Chloride:57 Alkalinity:55

I'm hoping the lowered sulfate and added chloride will take a hint of the 'sharpness' out of the coffee, possibly enhance the 'chocolate' aspect of it.

I've also retired my capresso infinity grinder. It's shot, makes tons of fines. Never realized how bad until I actually examined some of the ground coffee up close. I have a hario hand grinder I used very briefly before I bought the capresso, it's now back in service until my baratza virtuoso shows up. The hand grinder, set for the same grind size as the capresso, is far more consistent and has far less fines. While I'm happy about the better coffee I am far less enthusiastic about the hand grinding part of the caffeine ritual now.

 

[Silver_Is_Money]

In the spirit of further experimentation, I decided to come up with a slightly different profile.

In one gallon of RO water with a 4 TDS reading:
.25g Gypsum
.20g Calcium Chloride
.25g Magnesium Chloride
.3g Baking Soda

Ends up with a water profile of:
Calcium:34 Magnesium:8 Sodium:11 Sulfate:37 Chloride:57 Alkalinity:55

Let us know how it turns out with this profile.

 

[The_Bishop]

Sitting here sipping this as I type.

The coffee definitely has a softer mouthfeel. Chocolate notes are more prominent, but in balance with the fruitiness. The sharpness I thought might be contributed by the higher sulfates is definitely softer. Overall it's pretty good but I will probably cut back the baking soda on the next gallon. It might be because I'm so used to a more acidic bite to the cup, but it seems almost a little too smooth.

 

[Silver_Is_Money]

I think the next 5 gallons of RO that I modify for coffee use will get the following addition:

2.8 grams of CaCl2.2H2O (I.E., the dihydrate state of CaCl2*)
1.5 grams of Epsom Salt
1.4 grams of Baking Soda

*Note: For fresher CaCl2 at a presumed 95% purity level, this would become ~2.2 grams of CaCl2

 

[The_Bishop]

That should be interesting, let me know how it compares taste wise with the higher concentration of chloride.

 

[mabrungard]

I recently used a formulation of half gram of gypsum, calcium chloride, epsom, and baking soda per gallon. Essentially double the dosage suggested by Larry and it was pleasant. I’m getting the impression that coffee water content is forgiving. But I do feel that having sufficient alkalinity is probably important.

 

[The_Bishop]

Wow, that's a bit of an eye opener. Would think with the sulfates in the 125 range it would be very dry.

Might be worth talking about how the coffee is being made. I've been brewing inverted aeropress with a relatively fine grind, so full immersion.

 

[The_Bishop]

My Baratza grinder finally showed up.

My god, what an eye opener. What a difference a grinder makes. No fines, very consistent grind. Same coffee, same grind size, same weight of coffee, same water. Only difference is the grinder. Cup is 50% better.

 

[The_Bishop]

I think the next 5 gallons of RO that I modify for coffee use will get the following addition:

2.8 grams of CaCl2.2H2O (I.E., the dihydrate state of CaCl2*)
1.5 grams of Epsom Salt
1.4 grams of Baking Soda

*Note: For fresher CaCl2 at a presumed 95% purity level, this would become ~2.2 grams of CaCl2

Did you ever try this out, and how was it?

 

[Silver_Is_Money]

Did you ever try this out, and how was it?

I haven't tried it out yet. My wife likes coffee made from our RO water. But then I must note that our RO water (starting from a well with 720 ppm Total Hardness, and 377 ppm Total Alkalinity as CaCO3 per Ward Labs) weighs in at about 35 ppm alkalinity.

 

[The_Bishop]

Hmm. Maybe next time I run out of water for coffee I'll give it a shot.