High Water Alkalinity - Why Dilute?

I've read a lot on water chemistry, and there is one concept i still havn't been able to grasp, and that is the effects of high Alkalinity.

Is the only concern of water with high alkalinity a high mash pH? If you correct the pH with gypsom/cacl/lambic acid, and after that your other minerals are then where you want them, is there still a drawback to the source water having high alkalinity?

Is there any reason to dilute when i have to add gypsum/cacl anyways to get calcium in range? Adding a couple ml of lactic acid if needed to further drop the pH seems much simpler and even cheaper than buying distilled/ro water. Are there other "problems" high source water alkalinity might cause if i don't dilute?

You can get by without diluting to reduce alkalinity. But the other effects of high calcium or acidification can take a toll on the finished beer flavor. If the alkalinity is in the hundreds of ppm, then you might consider other alternatives to water treatment than bumping calcium or acidifying. Dilution is only one of the alternatives.

Another good alternative might be lime softening treatment. Since the water alkalinity is high, it means the temporary hardness is high too. Lime softening is ideal for reducing hardness and alkalinity. That might be something you should investigate.

Think of alkalinity as being a sponge (buffer). If you have high alkalinity it will take more water salts or acid to cause a change in pH to occur. The pH will change easily if your alkalinity is low.

Diluting hard water makes it easier to adjust the pH without having to use large amounts of chemical additions.

Ok, but lets remove the salts from the equation. Acccording to Palmer you can use up to 2ml per gallon of lactic acid before it beings imparting any flavors. It seems like you could bring the pH/alkalinity down to a reasonable range on just about any water without exceeding that recommendation for very cheap.

Are there other reasons you might not want to use lactic acid to reduce alkalinity? What other effects of using it are there to worry about?

bduane said:

Ok, but lets remove the salts from the equation. Acccording to Palmer you can use up to 2ml per gallon of lactic acid before it beings imparting any flavors. It seems like you could bring the pH/alkalinity down to a reasonable range on just about any water without exceeding that recommendation for very cheap.

Are there other reasons you might not want to use lactic acid to reduce alkalinity? What other effects of using it are there to worry about?

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In my case, my alkalinity is high. That makes my beers not taste really great. I can use 1 ml of lactic acid per gallon before I taste it, but that still doesn't get my pH in range. My chloride is low, so adding some CaCl2 is a good idea. But that doesn't do it either.

RO water costs $.78 cents for two gallons. I can buy 2 two gallon jugs and have no problem hitting my mash pH and getting the right flavor profile. so that's what' I've been doing.

The next thing I'm going to try is using slaked lime to drop my alkalinity.

bduane said:

Is the only concern of water with high alkalinity a high mash pH? If you correct the pH with gypsom/cacl/lambic acid, and after that your other minerals are then where you want them, is there still a drawback to the source water having high alkalinity?

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When you lower alkalinity with acid it is gone i.e. removed from the water as surely as when one dilutes it. The difference is that each molecule of HCO3- that has been removed with acid is replaced by an anion of the acid you used. This can be a problem if you don't want the flavors of the anion. It is not a problem if you were planning to augment chloride and/or sulfate. You use hydrochloric and/or sulfuric acids and kill 2 birds with one stone (problems of obtaining food grade HCl and H2SO4 aside).

bduane said:

Is there any reason to dilute when i have to add gypsum/cacl anyways to get calcium in range?

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To get rid of alkalinity as discussed without adding the anion of any acid.

bduane said:

Are there other "problems" high source water alkalinity might cause if i don't dilute?

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The one thing we haven't discussed in residual bicarbonate. Whether you dilute or use acid you won't remove all the bicarbonate. I always suggest that people put a little baking soda in a glass of water and taste it. Is this something you want in your beer if you don't have to have it? For me the answer is a very loud NO but then I think I am unusually sensitive to it/repelled by it. Therefore I use RO water (very low alkalinity) for everything.

Been brewing all grain for about a year. Some of my beers have been great but a few have had problems. I've never made a porter that I liked much - they are all harsh and have some astringency. People say my IPAs aren't all that hoppy, even though I have used a real lot of hops in some of them.

I think my main problem could be the alkalinity (as CaCO3) of my water, which is 160 ppm. I carbon filter it, but make no other adjustments. Besides residual treatment chemicals, the rest of my water profile is fine.

I've checked my mash pH with test strips and it showed 5.4, at 155°, so the room-temp pH is probably 5.8 right?

I guess my next batch will have to be with RO water, and a recipe I made that was really off, to see how it works out. I'm reading Water, maybe I'll come to more conclusions on how to deal with my water. For now maybe I'll start there...

... and I think I'm going to start shopping for a pH meter...

That is pretty high alkalinity...even for dark beer brewing. More than likely, you are suffering from high mashing and sparging pH and extracting all sorts of poor tasting constituents from your grain and hops.

The move to RO does provide you with a nearly clean slate. If you were adventurous, you could try dealing with your tap water. But I see you are in SoCal and that probably means Colo River water. Not good. So stick with the RO. You will need a TDS meter to check the RO water quality since you can never tell when those machines go bad.

If those pH readings were with paper pH strips, the reading is worthless. Not a hope that they read correctly. The colorpHast plastic strips do seem to have some consistency and you seem to understand the offset in their readings.

Correcting that apparently high pH condition will make a world of difference in your beers. Enjoy your education.

I live in an area served mostly by groundwater. In dry months they buy from MWD to meet demand. But the guy at my supplier said 11 months of the year I'm getting groundwater.

The report says MWD (Colorado River) water has alkalinity of 110 ppm.

So if I go 50/50 (carbon filtered tap water/RO water) with my mash water, should I just use all RO water for sparge?