Well water highly acidic - good or bad?

Most of the water advice on HBT seems to revolve around high alkalinity, as one might expect with city water. I have a well with low alkalinity.

I'm on a well in Redwood country, and our water comes in at pH 4.5 (no typo), fairly soft with very low total alkalinity. Not much as far as dissolved solids - the water is clean with no measurable bacteria. It does have a slightly metallic/sour taste, probably due to dissolved minerals and copper leached from pipes. We do plan to put a filter on the well next year, either reverse-osmosis or neutralizer-plus-carbon. This water is ok to shower with, and even to cook with, but I'm thinking it might be problematic for brewing.

I have made two batches with it: a porter that was quite good, and a Belgian wit that was terrible, but many things went wrong with that batch so it may not have been the water. I'm going to switch over to bottled water for the next batch, but wondered if anyone else had this same situation. If there is a way to capitalize on such acidic water, I'd like to give it a shot.

thanks

Jefro

jefro said:

Most of the water advice on HBT seems to revolve around high alkalinity, as one might expect with city water. I have a well with low alkalinity.

I'm on a well in Redwood country, and our water comes in at pH 4.5 (no typo), fairly soft with very low total alkalinity.

Click to expand...

By the ISO definition of alkalinity your well water has 0 alkalinity. Alkalinity is measured by adding acid to water until the pH reaches, in the ISO method, 4.5. If the AWWA procedure is followed another pH could have been used and that might explain a slight alkalinity but it would be quite small.

It is normal for well water to be low in pH but not that low. Please tell us the source of that pH information by which I mean to ask whether you measured it yourself and if so how, sent it off to a lab, someone in the neighborhood told you etc. The reason I'm asking this is because that number seems too low by at least 1 pH unit.

If that pH level is real CO2 should escape from the water sample upon even slight heating and/or agitation and the pH should rise. If it does not then the source of acid is something other than subterranean CO2 and the well should be investigated as the water may not be safe to drink.

jefro said:

It does have a slightly metallic/sour taste, probably due to dissolved minerals and copper leached from pipes.

Click to expand...

If the pH is really that low the water is going to taste sour just from the dissolved CO2 (assuming that is the source of the low pH). Water with pH that low is going to be quite corrosive and metallic piping will spring pin hole leaks within a couple of years.

jefro said:

We do plan to put a filter on the well next year, either reverse-osmosis or neutralizer-plus-carbon.

Click to expand...

Unless your plumbing is PEX I'd look into getting a neutralizer sooner rather than later.

jefro said:

This water is ok to shower with, and even to cook with, but I'm thinking it might be problematic for brewing.

Click to expand...

You definitely need to get this water tested. If the report shows that low pH and not much of anything else then there is no problem in brewing with it. Just heat it (as in the HLT) and the CO2 will be driven off leaving you with low mineral water which is the best starting point for brewing because you can meet any particular style requirement simply by adding some salts.

jefro said:

If there is a way to capitalize on such acidic water, I'd like to give it a shot.

Click to expand...

The fact that the alkalinity is 0 gives you the advantage mentioned above but that assumes that you have essentially pure water with nothing else but CO2 dissolved in it. If the calcium content of this water were at 20 mg/L that would stay but the water would fizz up when it came out of the faucet and I doubt that's happening so the actual hardness probably is low.

Now testing is going to be a problem since it will be hard to capture a sample, seal it and ship it off to a lab without having the pH climb from loss of CO2 but it's probably worth doing that anyway to see what else is in there. You need to get a tech who knows how to use a pH meter out to measure the water right as it comes out of the pressure tank.

That well water pH is not too low by any measure. When starting with rain water that then flows through non-carbonate that may also contain metal ores, the potential to drive the water pH down is great. I'm sure that many have heard of acid Mine Drainage. It is a very common problem. The OP's indication of a metallic taste is not a surprise for this water. This water pH is not likely due to excess CO2 content.

The most important thing to determine is the metallic content of this water along with the typical Secondary parameters that we brewers need to know. If the water has elevated iron or manganese, then ion-exchange softening may be quite suitable for this water. It will take the metal ions out. Since the concentration of those metal ions is probably very low, the consequences of using the ion-exchange softener will be small. The increase in either sodium or potassium ions due to the softening will be minor.

Of course, check out Bru'n Water and read about these metallic ions on the Water Knowledge page of the Bru'n Water website.

Brewing with acidic water with its very low alkalinity is quite possible. It will just require that the brewer know how to add alkalinity as needed for each brew. Bru'n Water has the tools for that. Pickling Lime is the preferred alkalinity source.

Enjoy!

Thinking about this a little more it occurred to me that given that you live in the Peoples Republic (or is it Bear Flag?) you doubtless required a well test in order to get an occupancy permit and therefore the water is probably not contaminated by mine runoff (which is what I was thinking of when I cited safety concerns in #2) unless the well was certified years and years ago and something has happened since then. I am really leaning towards a bad pH reading but I would be concerned enough to do further checking and do it soon.

Yes in the Republic but in the "good part", far northern coast where all the wineries & whales are. No mines nearby, but redwood bark is quite acidic and it is my understanding that there are simply not enough salts left in the ground to buffer it by the time it gets to our well (100 ft deep). Prior to this, we lived with a 25ft well that was also about like this, and we replaced copper pipes regularly. Some of the older ones were just paper-thin and crumpled when I touched them.

We did get a water test when we drilled the well 6 yrs ago. pH was 4.6 then. I just measured it with litmus paper last week and got the 4.5 figure. I did a DIY water test recently, which is how I determined we were low on cal/mag, no iron, no bacteria. I definitely agree on the neutralizer. I am curious, though, to know whether there could be anything other than CO2 making it that acidic, perhaps something I haven't tested for. We obviously need a full water test and a neutralizer. I'm guessing I should probably filter out the salts that the neutralizer will add as well.

Interesting about pickling lime, I hadn't considered that! Our country store has some, might be worth a try.

I'm brewing a brown ale this weekend with bottled water, will be interesting to see how it differs from the porter I brewed with our acidic tap water.

Thanks much for the replies

Any acid can render the pH this low if there is enough of it and it is strong enough. The thing that got knee jerk reaction from both me and Martin was the possibility that it was mine runoff which contains, among other things, sulfuric acid from the oxidation of pyrites. Thus if your water contained sulfate at this pH that is equivalent to having sulfuric acid in your water. It only takes very little sulfuric acid to move low ion water to pH 4.6. Acids produced by the decaying of vegetation could presumably do the same thing but I'd expect that the water would taste pretty bad if that were the case.

I'd try to find something more accurate than litmus paper to test with. pH strips aren't great but they'll do but a pH meter would be better still.