The reason this is an in progress is that it is based on an article I am writing for Brewers Contact, and I can't 'release' it until it has come out there.
The most important thing to correct for all grain beer is the alkalinity of the liquor, which assists greatly in getting the mash pH where you want it to be. As I have said in the past there is no point in throwing acid into the liquor without knowing the alkalinity that is present. In the dim distant past water authorities used to quote the alkalinity on their water reports . . . However the water companies no longer do so, which means we either use increasingly out of date information, wing it, or come up with some way of measuring it. Basically the methods I have used in the past involve titrating acid of a known concentration to a pH (pH4.3) and using either an accurate (read expensive) pH meter or an indicator, methyl orange 4% . . . you need 4 drops and its sold concentrated in packs of 1L. . . . hardly convenient. Luckily another option is now available which is quick, cheap and sufficiently accurate, Salifert Carbonate Hardness/Alkalinity Test Kit Or from aquacadabra
The kit is surprisingly simple, you add 4ml of of water to a test tube, and then add 2 drops of indicator solution which turns the water blue/green. You then add drop by drop from a syringe with a fine tip the KH Reagent (Acid of a known concentration) to the test tube, swirling to mix the contents. Eventually the solution turns orange-red/pink. You then compare the amount of acid used with a table to determine the alkalinity in meq/L . . . multiply that by 50 to give the alkalinity in mg/L (ppm) as CaCO3 . . .
Testing against Blackpool water (normally around 24mg/L) used between 0.08 and 0.1ml id Reagent which gave (from the table) an alkalinity between 0.46 and 0.57 meq/L which when multiplied by 50 gives the alkalinity as 23 and 28.5 . . . the accuracy of the kit is .11meq/L or 5.5 mg/L as CaCO3. . . . although this can be increased by using double the qty of water and halving the value obtained.
This table shows the relationship between the reading and alkalinity directly with no complex maths involved.
TODO: Add a video showing how to do a test
Basically you take the reading where the end of the plunger crosses the scale so 0.95 in this case.
And this is the colour change, the end point is where the permanent colour change becomes blue/pink purple not pink as it says in the instructions
The most important thing to correct for all grain beer is the alkalinity of the liquor, which assists greatly in getting the mash pH where you want it to be. As I have said in the past there is no point in throwing acid into the liquor without knowing the alkalinity that is present. In the dim distant past water authorities used to quote the alkalinity on their water reports . . . However the water companies no longer do so, which means we either use increasingly out of date information, wing it, or come up with some way of measuring it. Basically the methods I have used in the past involve titrating acid of a known concentration to a pH (pH4.3) and using either an accurate (read expensive) pH meter or an indicator, methyl orange 4% . . . you need 4 drops and its sold concentrated in packs of 1L. . . . hardly convenient. Luckily another option is now available which is quick, cheap and sufficiently accurate, Salifert Carbonate Hardness/Alkalinity Test Kit Or from aquacadabra
The kit is surprisingly simple, you add 4ml of of water to a test tube, and then add 2 drops of indicator solution which turns the water blue/green. You then add drop by drop from a syringe with a fine tip the KH Reagent (Acid of a known concentration) to the test tube, swirling to mix the contents. Eventually the solution turns orange-red/pink. You then compare the amount of acid used with a table to determine the alkalinity in meq/L . . . multiply that by 50 to give the alkalinity in mg/L (ppm) as CaCO3 . . .
Testing against Blackpool water (normally around 24mg/L) used between 0.08 and 0.1ml id Reagent which gave (from the table) an alkalinity between 0.46 and 0.57 meq/L which when multiplied by 50 gives the alkalinity as 23 and 28.5 . . . the accuracy of the kit is .11meq/L or 5.5 mg/L as CaCO3. . . . although this can be increased by using double the qty of water and halving the value obtained.
This table shows the relationship between the reading and alkalinity directly with no complex maths involved.
Code:
Reading Alkalinity Reading Alkalinity Reading Alkalinity
In ml In ml In ml
0.98 16 0.64 110 0.30 203
0.96 21 0.62 115 0.28 209
0.94 27 0.60 121 0.26 214
0.92 32 0.58 126 0.24 220
0.90 38 0.56 132 0.22 225
0.88 43 0.54 137 0.20 231
0.86 49 0.52 143 0.18 236
0.84 54 0.50 148 0.16 242
0.82 60 0.48 154 0.14 247
0.80 65 0.46 159 0.12 253
0.78 71 0.44 165 0.10 258
0.76 76 0.42 170 0.08 264
0.74 82 0.40 176 0.06 269
0.72 87 0.38 181 0.04 275
0.70 93 0.36 187 0.02 280
0.68 98 0.34 192 0.00 286
0.66 104 0.32 198TODO: Add a video showing how to do a test
Basically you take the reading where the end of the plunger crosses the scale so 0.95 in this case.
And this is the colour change, the end point is where the permanent colour change becomes blue/pink purple not pink as it says in the instructions
