Water

The condition of brewing water is adequately covered in this blog article by Braukieser on Mash pH.

For a deeper look into brewing water, this is the defacto guide, which gets heavy in places. The John Palmer book : Water - A Comprehensive Guide for Brewers

The basics:

• Hardness in water is present as Carbonates, Bicarbonates and Carbonic Acid
• Grain and water combine to form a mash pH which is best measured 10 mins into the mash and the sample should be cooled to room temperature before testing
• Base malts and crystal malts have an Acid buffer effect on the water in the mash and the strength of that bufferring effect is correlated to its colour
• Roasted darker malts do not have an Acid buffering affect
• Water pH and hardness details are not important. Mash pH - where the pH rests when base malt and water is combined - is important as this drives key processes that start in the mash and follow into the brew, such as the conversion of starches to to ferment-able sugars (sugars that yeast can eat which makes them piss alchohol and fart CO2)
• Chloride does not effect mash pH
• Sulphate : Chloride ratio 1:1 = balanced malt to hop taste. Adjusting salt additions to effect this ratio will accentuate malt or hop dominance.  
• Acceptable Mash pH range is 5.2 - 5.7
• Ideal Mash pH range is 5.3 - 5.5

This is what I am aiming for with water treatment:

Transparent

That it removes impurities such as heavy metals, paracites, VOC's etc and adds pure salts

Simple

Difficult to get wrong, easy to repeat

General 

As source water is likely to vary slightly, the treatment should work without further testing other than checking the mash pH 10 mins in to the mash

Zero Chlorine

Chlorine and Chloramine (Chlorine + Sulfur) is terminal for yeast.

Recipes 

Works for pale and extra pale malts, which would require a total alkalinity of less than 25ppm

Water Source

As we are located in the South Downs in East Sussex, we know that our water is hard.

'Unless you put a number to it, you haven't proved anything'. 

(i'll dig out the quote source at some point).

After some googling around I cam across this blog post on Jims Beer Kit about water alkalinity. I followed this and obtained  a Salifert KH + Alkalinity Prof-Test Kit which is designed for Aquarium hobbyists. This gave me the following results:

Water Treatment	KH value in dKH	Alkalinity in meq/L	mg/L Calcium Carbonate CaCO3 (Chalk)
Plain Tap Water (Unfiltered)	10.7	3.82	191
Filtered* Tap Water	10.7	3.82	191
Filtered* Tap Water, boiled in the Kettle	6.7	2.39	119.5
Filtered* Tap Water, boiled for 30 mins	2.2	0.79	39.5
Filtered* Tap Water, boiled for 60 mins, allowed chalk to settle out	1.4	0.5	25
Filtered* Tap Water, boiled for 60 mins, allowed chalk to settle out, then britta water filtered	0.6	0.22	11

* Frank 3 FilterFlow tap installed in our kitchen sink

This was a good start. Points of interest from the numbers above:

• The Franke 3 Filter Flow filter has no effect on hardness. This correlates with their literature.
• The water is of a medium hardness. I had previously thought it was very hard.
• Boiling for more than 30 minutes precipitates more chalk.
• That this method can get the water hardness down to below 25ppm & mg/L required for usage of pale malts, i.e Pilsner, 2-row etc.

I then set out to find out more. I discovered the Brewers Friend website where they have a set of helpful calculators. In particular their Mash Chemistry and Brewing Water Calculator seemed to be useful. This requires:

Calcium (Ca+2)
Magnesium (Mg+2)
Sodium (Na+)
Chloride (Cl-)
Sulfate (SO4-2)
Alkalinity (as CaCO3)
pH

I started at my water supplier, Southern Water and found a page call How Hard Is Your Water?

I was able to find out:

• Southern Water do not add Chloramine to the water. Although this can occur naturally in stream water in the area. 
• They don't test for Calcium, Magnesium & Sulfate
• Hardness in CaC03: 234 ppm average
• Sodium: 17.4 ppm average (low=15.4, high=21.8)
• Chloride: 33.25 ppm average (low=30, high=40)

So there were still some numbers that I didn't have.

After receiving the water report from Murphy & Sons I now have most of the important mineral content levels, PH and hardness. They don't test for Sodium but I have that figure from the Southern Water Report - above.

	Murphys Water Report	Southern Water Report	Home Testing
pH	6.93
Nitrate	2.5	33.308
Calcium (Ca+2)	77.59
Magnesium (Mg+2)	2.71
Chloride (Cl)	43.72	Low:30-Avg:33-High:40
Sulphate (SO4-2)	12.68	Low:13-Avg:16-High:21
Alkalinity (CaCO3)	175
Sodium (Na)	Not tested for	Low:15-Avg:17-High:21
Total Hardness (CaCO3)	207		No boil:199 /boil .5h:90 / boil 1h:35 / boil 1h+filter:11

NB: All values in ppm which is equivalent to mg/L which is equal to the same value as ppm

Water Prep

The water treatment I have settled for

Equipment

Burco 30 Litre Boiler - modded with ball valve and sight glass
Frank 3 FilterFlow tap installed in the kitchen sink
2 x 23 Liter PET Carboys

Overview

1.    Run water slowly through Franke 3 activated carbon and ceramic filter

2.    Boil for 1 hour

3.    Filter with a brita filter

4.    Add Calcium Sulphate and Epsom Salts to the grain bill prior to mash

Procedure

Slowly fill Carboys with filtered water and carry to boiler
Fill boiler to 26 liters
Bring to boil

Maintain boil for 60 minutes
An amount of the water at the bottom will be allowed for chalk precipitation 
Leave to cool

10% boil off will result in 26 Litres - 2.6 Litres = 23.4 Litres

Transfer as much as possible from the boil kettle to carboy leaving chalk behind
Repeat to fill 2nd carboy

As added to boiler for use, put through britta carbon filter

Effect of Boil

As chalk (temporary hardness) is precipitated from the water as CaCO3, the calcium levels will be too low and salts will need to be added. Usually this is done by adding Calcium Sulphate (Gypsum), or Calcium Chloride which also pull the water towards acidity.

Salt Adjustments To Grist Pre-Mash to lower pH (raise acidity)

Salts are best added to the grist before adding to mash tun. Calcium can also be added to the mash if it has been measured as having too high a pH.

Optional additions:

Calcium Chloride
Calcium Suplhate
Epsom Salts

Acid Adjustments to Mash to lower pH (raise acidity)

German beers rely on Lactic Acid for their use of pale malts. This is the way I want to go. 

The maximum Lactic acid that can be added to a mash is 1ml per KG of grist.

ml per KG			Malt kg	Min to achieve a movement of 0.1	Max ml in batch before flavour negatively impacted	Min Possible Change	Max Possible Ph Change
0	.	25	5.1	1.28	5.1	0.1	0.4
0	.	26	5.1	1.33	5.1	0.1	0.4
0	.	27	5.1	1.38	5.1	0.1	0.4
0	.	28	5.1	1.43	5.1	0.1	0.4
0	.	29	5.1	1.48	5.1	0.1	0.3
0	.	30	5.1	1.53	5.1	0.1	0.3
0	.	31	5.1	1.58	5.1	0.1	0.3
0	.	32	5.1	1.63	5.1	0.1	0.3
0	.	33	5.1	1.68	5.1	0.1	0.3
0	.	34	5.1	1.73	5.1	0.1	0.3
0	.	35	5.1	1.79	5.1	0.1	0.3
0	.	36	5.1	1.84	5.1	0.1	0.3
0	.	37	5.1	1.89	5.1	0.1	0.3
0	.	38	5.1	1.94	5.1	0.1	0.3
0	.	39	5.1	1.99	5.1	0.1	0.3
0	.	40	5.1	2.04	5.1	0.1	0.3
0	.	41	5.1	2.09	5.1	0.1	0.2
0	.	42	5.1	2.14	5.1	0.1	0.2

Examples:    By adding the maximum 1ml/KG the maximum change will be between 0.2 and 0.4           
    To move the Ph by at least 0.1 requires between 1.28ml and 2.14ml for 5.1KG of grist

Finally!

I have all the information! So I can now use the Brewers Friend Mash Chemistry and Brewing Water Calculator

It is likely that all additions will be with the aim of reducing pH. The plan would be to add salts to grist prior to mash then add Lactic Acid should the pH require lowering.

The salt additions will very depending on the recipe, i.e. use of base and crystal malt. Hence the requirement to use a mash calculator.