Boiling to remove chalk

[befuggled]

I have to boil here because of the very high hardness. Thames Water quotes 283 mg/l.
(I am waiting for Salifert kits to get a bit better idea of alkalinity).

It is written that thou shalt boil for 15-30 minutes and leave for the chalk to precipitate.
Does anyone know for how long? to what temperature?
70l boiled and left overnight drops to 40C by the morning.
Can I speed this up?
If I fit an immersion cooler in the boiler specifically for this (I am using Counter Flow for wort cooling at the moment), will it assist or hinder?
Any answers or opinions greatly appreciated!

[Dr. Dextrin]

My alkalinity is in the same ballpark and I tend to leave it to cool to room temp. I don't know if that's really necessary, though. If I understand the theory correctly, the chalk is precipitated during the boil so it should just be a matter of getting it to settle out whatever the temperature.

Actually, I'm also concerned about how long I should boil for. For my last brew, I skimmed the water with a sieve while boiling it because the chalk tends to form a scum on the surface. I expected this to stop after a bit once all the bicarbonates had been removed. But actually, the scum continued to form. I extended the boil to 30 minutes and it was still forming at the same rate.

So now I'm not really sure if I'm getting all the bicarbonates out even with a 30 minute boil. I guess it's possible the scum has nothing to do with this (it could just be the deposit from the side of the boiler being washed off and rising to the surface), but I'm starting to wonder if anyone has ever checked how effective this boiling regime actually is. I'm still struggling to get my mash pH down (it's close, but still not quite right) so it's something I need to check.

When I remember, I'm going to check the alkalinity after the boil with a Salifert kit to see if it's done a useful job or not. Unless I get into CRS beforehand, that is.

[befuggled]

Thanks Doc,
It sounds like we are in a similar situation, but I don't get as much scum as you do.
I would prefer to force cool the water because my FVs are in the same very small room, so left overnight it can get rather warm.
I could pump to the HLT via the CF cooler, but I don't want chalk getting into that, or being premature and getting chalk into the HLT...
When I get time, I will use the Salifert Kit, which arrived two days ago, to test the water before and after boiling.
I have looked into CRS and bought some thinking I would try it, however, when I stick my figures from Thames Water into Graham's calculator I get:
"Your target liquor cannot be matched with the current sulphate and chloride values" (For General purpose, Burton, Lager etc).
I also need to look at how Grahams sums work!

[jubby]

This may help a bit.

My alkalinity is not as high as yours (234mg/lCaC03) and I boiled for 30 mins, allowed to cool but did not check the temp, probably around 40C; warmish. Did an alkalinity check and it was 52 CaC03. Just to prove that it works really.

befuggled wrote:
I have looked into CRS and bought some thinking I would try it, however, when I stick my figures from Thames Water into Graham's calculator I get:
"Your target liquor cannot be matched with the current sulphate and chloride values" (For General purpose, Burton, Lager etc).
I also need to look at how Grahams sums work!

I have this with some water profiles also (Burton and lager). CRS raises the Chloride and Sulphate levels a fair bit. If you play around with GW's calculator and 'check' the boil and CRS boxes, you will see the levels change. Boiling seems to be the only alternative for me.

The force cooling idea is interesting, but i can't answer your question though. I would have thought that cooling it was ok as long as the sediment has settled, but not sure.

[Dr. Dextrin]

Cripes! I guess I'd better check with GW's calculator before I fork out for some CRS. If boiling is really the only option AND I need to boil for 30 mins or longer to zap all the bicarbs, that'll be a real pain. Especially as my boiler isn't big enough to do the whole lot in one go. Treating my water is starting to feel like a brew day in itself!

Actually, this thing about cooling is also pretty important. Not only does cooling take a lot of time (or effort if you force cool), but you then immediately heat all the water back up again and that takes yet more time and, of course, energy. I guess the thing to do is try not cooling and test the water after treatment.

While I'm on the subject, another thing I've noticed is that water I've treated by boiling tends to foam a lot. If I boil some in the kettle, chances are it'll foam out the top. The same happens if I top up my boiling wort with it. Has anyone else noticed this? It's another reason I'm worried that I may not be getting all the undesirables out just by boiling.

[jubby]

Dr Dextrin wrote:
Cripes! I guess I'd better check with GW's calculator before I fork out for some CRS. If boiling is really the only option AND I need to boil for 30 mins or longer to zap all the bicarbs, that'll be a real pain. Especially as my boiler isn't big enough to do the whole lot in one go. Treating my water is starting to feel like a brew day in itself!

Hang on a minute DD Theres no need to be able to treat your water to suit every profile. It may be fine with just CRS and a little Gypsum/Calcium Chloride. Boiling is the only option if i want to brew lager or Burtonize. I can get away with just CRS in most cases. It depends on your waters mineral content.

Actually, this thing about cooling is also pretty important. Not only does cooling take a lot of time (or effort if you force cool), but you then immediately heat all the water back up again and that takes yet more time and, of course, energy. I guess the thing to do is try not cooling and test the water after treatment.

It is time consuming, but energy costs are generally offset by not using CRS. if you buy from BB at £1.70, use about 50ml per brew (you have high alkalinity) that's 5 brews costing 34p per brew. If you use an electric boiler it costs 7p per KW per hour (thats my electricity tariff) , so a 3KW boiler can run about 1 1/2 hours for the same cost. I can't beleive i have just sat here and worked all that boll*cks out. My excuse is that I am at work and bored

[Graham]

50 ppm as CaCO3 is about right for a standard 30 minutes boil (without doing anything else).

If you add your calculated amount of calcium sulphate (or calcium chloride) before the water comes to the boil, you will achieve about 35ppm as CaCO3. This lowers the alkalinity because of the solubility product of ions principle - the more calcium in solution, the less carbonate can remain in solution. Do not add any other stuff, such as Epsom salts, before you have removed the water from the precipitate because that will have the opposite effect.

A further problem is that some carbonate, although out of solution, remains as finely divided particles in suspension that are not heavy enough to fall out of suspension quickly enough, if at all. This gives a higher than normal reading. Trickling the water through an improvised filter, will remove these particles and you will achieve about 25ppm as CaCO3. The improvised filter that I used for the test was a metal flour sieve, lined firstly with a microfibre cloth, and then lined on top of that with those green scrubby things (do they have a name?) and trickling the water through it (without much cooling). It is probably over the top though - the 35ppm achieved in the above paragraph is good enough.

CRS puts far too much chloride in the water for my comfort, and the higher the alkalinity of your original water the greater the problem becomes. It gets even worse if one uses DLS for calcium addition, because it adds yet more chloride.

Murphy's are too fond of their chloride in my view anyway. Even their suggested water profiles given at the bottom of the article HERE has loads of chloride recommended even for a bitter. These levels are far higher than would be found in any natural water, and particularly high when one considers that pale ales traditionally have next to no chloride.

The problem would be eased if we could press-gang one of the suppliers into making a sulphuric-acid solution available as an alternative to CRS - which will add no chloride.

The solution for people who prefer to use CRS, is to lower their alkalinity to their desired levels, adjust their calcium levels, if necessary, with gypsum only, and accept the water profile that they end up with. Thing is that part of the fun of home brewing is the adjustment and the tweaking and the experimenting and the playing and the...

[jubby]

Graham wrote:
If you add your calculated amount of calcium sulphate (or calcium chloride) before the water comes to the boil, you will achieve about 35ppm as CaCO3. This lowers the alkalinity because of the solubility product of ions principle - the more calcium in solution, the less carbonate can remain in solution. Do not add any other stuff, such as Epsom salts, before you have removed the water from the precipitate because that will have the opposite effect.

Just to clarify that Graham. When i boiled my water to Burtonise it in accordance with the procedure in your book and your calculator, i added the total recommended calcium additions to the treatment boil, boiled for 30 mins, cooled, then added a little epsom (no more calcium). I am pretty sure thats correct, can you confirm that please.

[Dr. Dextrin]

50 ppm as CaCO3 is about right for a standard 30 minutes boil (without doing anything else).

Thanks for that Graham, it's always good to have some facts and figures.

Have you investigated how this final alkalinity depends on the starting alkalinity? Is it possible that people who have mind-boggling carbonate levels aren't going to get that low with a 30 minute boil? Or is it a sort of floor that you reach no matter where you start from?

[Graham]

Just to clarify that Graham. When i boiled my water to Burtonise it in accordance with the procedure in your book and your calculator, i added the total recommended calcium additions to the treatment boil, boiled for 30 mins, cooled, then added a little epsom (no more calcium). I am pretty sure thats correct, can you confirm that please.

Yep, that's fine. 52ppm as CaCO3 is fine too. In fact your true alkalinity will probably be somewhat less, because the test kits tend to overestimate alkalinity at low alkalinity levels.

In theory it is better to rack the water off the precipitate while it is still hot, because the solubility of both carbonate and CO2 is less at high temperatures, but that is a compromise between giving enough time for the particles to settle and the negative affects of not getting the water off the precipitate quickly, causing some of it to redissolve. In practice it probably makes little difference.

[jubby]

Just to clarify that Graham. When i boiled my water to Burtonise it in accordance with the procedure in your book and your calculator, i added the total recommended calcium additions to the treatment boil, boiled for 30 mins, cooled, then added a little epsom (no more calcium). I am pretty sure thats correct, can you confirm that please.

Yep, that's fine. 52ppm as CaCO3 is fine too. In fact your true alkalinity will probably be somewhat less, because the test kits tend to overestimate alkalinity at low alkalinity levels.

In theory it is better to rack the water off the precipitate while it is still hot, because the solubility of both carbonate and CO2 is less at high temperatures, but that is a compromise between giving enough time for the particles to settle and the negative affects of not getting the water off the precipitate quickly, causing some of it to redissolve. In practice it probably makes little difference.

That's great, ta.

[befuggled]

Thank you all!
I am getting a lot better idea now.
I had already boiled up this morning, adding gypsum and a bit of salt as your calculator Graham. I took a sample at about 80C and put it to one side. I pumped up to the HLT at about 60C, not wanting to waste too much energy getting it up to 83C for starting.
Later on, I tested both the "raw" water and the boiled:
Raw: 165 ppm
Boiled: 30 ppm

Within the expected accuracy, that sounds pretty good!
This will probably be my regime in future, but if I want to cool before leaving overnight, I will try sending the next lot through the CF cooler and then measure after that.
It certainly sounds that getting it off the sediment at 80C has produced a very good if not optimum result, thanks Graham.

Doc, it sounds as if something else is causing your foaming; it never foams out of the kettle here!

Now I had a bottle of 60% suphuric somewhere, for tin plating I recall, that is if I didn't accidently drink it....

[Graham]

Have you investigated how this final alkalinity depends on the starting alkalinity? Is it possible that people who have mind-boggling carbonate levels aren't going to get that low with a 30 minute boil? Or is it a sort of floor that you reach no matter where you start from?

There is a relationship with how much alkalinity you start with as to how much you can get out, but I have only seen reference to it a couple of times, and the science would be beyond me anyway. Generally there is a maximum solubility of calcium carbonate in water, but references vary enormously as to what that figure is. It varies between 14mg/l and 47mg/l depending upon which reference you look at, so I regard 47mg/l as the maximum level you will achieve by boiling, and in practice it will be less. I have achieved 25mg/l without too much difficulty. It certainly depends greatly upon what is already in the water, which is why It is a good idea to add other calcium-containing salts to the water during the boil for the "common ion" effect take place.

There is an issue inasmuch as not all of the carbonate falls out but remains as fine particles in suspension. Like beer fining, the chalk particles need to floc together to form bigger particles that are heavy enough to drop out. With water of low alkalinity there is sometimes not enough chalk present to form large enough flocs to be heavy enough. Therefore it can be difficult for people with low alkalinity to reduce it further by boiling. In this instance it is often necessary to add some precipitated chalk to the water to provide nucleation zones for the flocs to form. It seems strange to need to add chalk to the water to assist in removing it, but such is the case. Rudimentary filtering is another solution.

[Graham]

I realise DLS is crap but what's wrong with an extra ~70 mg/l (in the above example, less for most people) of chloride from CRS btw, it doesn't have any flavour impact at that level and water profiles can tollerate 3 or 4 times that amount ?

I was not suggesting that DLS is necessarily crap, it is probably a useful product, but I cannot see much point in it when the constituents are available separately, and by using separate stuff one is not constrained by the fixed sulphate-chloride ratio( 2:1) that DLS supplies.

CRS, on the other hand, provides equal parts sulphate and chloride in milliequivalent terms, which works out about 1.35:1 sulphate to chloride ratio in real-world weight terms (mg/l). Therefore by using CRS, in high alkalinity water, it is difficult to achieve any ratio other than 1.35:1. Indeed, Murphy's own profile for bitter suggests a 2:1 ratio, which is impossible to achieve with my water using Murphy's own products (at least those that are available to us). Notwithstanding that I think the amount of chloride specified by them is far too high anyway.

To be fair, it is impossible to achieve the bitter profile given in the Murphy's data no matter whose water or who's chemicals you use, because it does not represent anywhere near a balanced water. The only way to make it balance is to throw lots (330mg\l) of ordinary table salt into the water. Needless to say they omit a sodium figure in their data. (And there is no mention of pale ale either, which probably tells a story in itself)

It would be nice to have an alternative to CRS that does not put us into this chloride straight-jacket.