Some comments FWIW ...

cmin wrote:I get the "no scale" love with Pavlis but taste/feel matters more to me lol. So wondering where I should go from here? Maybe add a tiny amount of epsom?

That might be a worthwhile experiment for you. If you were to add 0.4 g of Epsom salt and 0.4 g of potassium bicarbonate to a gallon your water would have the same bicarbonate alkalinity (53 mg/l as CaCO3) as your rpavlis style water, but would also have a total hardness of 43 mg/L, all due to magnesium ion, and you would have no worries about scale formation. It would have about 40 mg/L of sulfate ion which is probably OK for machine health and taste. Be sure to give the mix a good shake and some time for the Epsom to dissolve fully.

You could give it a blind taste test, comparing Epsom vs no-Epsom water to see if you can't see a taste improvement over the rpavlis. I think it would be valid to do this comparison using V60 brews.

You can also try a lesser amount of bicarbonate, maybe 0.2 grams per gallon. For some coffees this might give you a clear taste improvement in the V60 brew. For espresso, which tolerates a lot more bicarbonate than pourover, I think you are less likely to notice a difference.

ojt wrote:water 1: 22mg/l TDS, of which 3.3 calcium and 11 bicarbonates
water 2: 38mg/l TDS, of which 7.5 calcium and 16 bicarbonates
water 3: 80mg/l TDS, of which 19.9 calcium, 56.8 bicarbonates

Might be useful to see these numbers converted to chemical equivalence units. In CaCO3 equivalents this would be:
water 1: 8.3 mg/L calcium hardness, 9 mg/L bicarbonate alkalinity
water 2: 19 mg/L calcium hardness, 13 mg/L bicarbonate alkalinity
water 3: 50 mg/L calcium hardness, 47 mg/L bicarbonate alkalinity

cmin wrote:But now you read on here and people make it seem like using spring water is going to spontaneously combust your machine lol.

That's because of the really wide variety of minerals that might be in a particular spring water. Even if you use Crystal Geyser spring water, which is often recommended here, you have to be careful to check the fine print - it comes fro seven different sources, some of which would be a terrible choice for use in an espresso machine. See Best bottled water for espresso machine .

There are very few reputable taste experiments out there that deal with coffee brewing water. One good one that has been around for ages can be found in Jim Schulman's Insanely Long Water FAQ. The most scientific one I've come across is from the SCAE folks, on page 20 of this Cafe Europa magazine: http://scae.com/images/caffee-europa/CE61.pdf *. Note that the taste differences found were small, and if anything the lower hardness water fared well in this case. Doing these taste tests well, with multiple samples, expert tasters, and different coffees is a monumental chore - that's probably why you don't see many of them.


* Edit addition: SCA members can find a copy of this report, titled Why Does Water Quality Matter?, in the scientific research section of the SCA available research page (for SCA members) here: https://sca.coffee/available-research-members/

The point of the bicarbonate in RPavlis water is to provide buffering against the acid in coffee. This could cause blander or more muted flavors, particularly in coffee that has muted acidity to begin with. You could always try reducing the amount of bicarb used and see if that is more to your taste. I wouldn't recommend using pure water with no bicarb at all in an espresso machine because you don't want it to become acidic and corrode your boiler. For brewing on the other hand, scale or corrosion really isn't a concern so if it tastes good do it.

I personally use one of the barista hustle recipes, which also uses potassium bicarbonage but adds magnesium sulfate (epsom salts) to the mix. This added magnesium reportedly improves flavor and extraction. RPavlis disputed this. I think measurably changing extraction is questionable, but changing flavor is of course subjective and difficult to prove. Give that a shot maybe also and see if you feel like it's an improvement. Again, you can always use less bicarb if you think its too bland.

Yeah I think I'll try .4g epsom added and see, test that and the spring water as well. I feel like the problem with RPavlis recipe as is, just like regular distilled basically which doesn't taste good to drink and that has to carry over as I'm seeing with coffee brewing.

I have found (by accident at first) that a lot of my preferred coffees taste better with significantly more bicarbonate than the RPavlis recipe calls for. Double to triple

homeburrero wrote:Some comments FWIW ...

You can also try a lesser amount of bicarbonate, maybe 0.2 grams per gallon. For some coffees this might give you a clear taste improvement in the V60 brew. For espresso, which tolerates a lot more bicarbonate than pourover, I think you are less likely to notice a difference.

Are you still using your simple mix of about 0.2 mmol/L each of calcium carbonate, magnesium carbonate, and potassium bicarbonate (CaCO3 equivalents of 20 mg/L calcium hardness, 40 mg/L total hardness, and 50 mg/L alkalinity)? Any take away after all this time?

K9drivr wrote:Are you still using your simple mix of about 0.2 mmol/L each of calcium carbonate, magnesium carbonate, and potassium bicarbonate (CaCO3 equivalents of 20 mg/L calcium hardness, 40 mg/L total hardness, and 50 mg/L alkalinity)? Any take away after all this time?

Yes. I use that because it has healthy alkalinity with some minerals similar to what you would get in a soft natural water. Works for my taste (or lack of taste?) - - I can't say that it's any better than plain rpavlis.

walr00s wrote:I have found (by accident at first) that a lot of my preferred coffees taste better with significantly more bicarbonate than the RPavlis recipe calls for. Double to triple

So I decided to play around again and just did side by side. 1g distilled with .38mg potassium bicarb, just like before mehhh and bland, and super thin crema. Also like no fruit notes almost just like more of a generic brightness/acidity which is what I recall before, I really don't understand how so many people can rave about the recipe as is like that. The other gallon I did .5mg potassium bicarb, and .4mg epsom salt, much better. The acidity seemed to be tamed and fruit notes popping again like spring water. This is with a medium light Burundi. From Windmill by the way, absolutely declious, so much strawberry.

I'm going to play around further and increase potassium bicarb after this tank and see. Maybe do .8mg and keep epsom the same.

0.4mg per GALLON? And you can taste it?

Opps meant g, used my mg scale. .38g and .4g lol

aha, I was a bit confused! Makes sense now, I also recall using more and getting better taste, but keep in mind that RPavlis came up with the recipe to protect the boiler from the acidity of water.