(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
adm wrote:I have to add about 0.52ml of the reagent to a 4ml water sample to get the colour change, and the conversion chart supplied with the kit says this is a KH value of 7.7 i dKH (whatever that means), or an Alkalinity figure in Meq/L of2.74
The left-most column in the conversion table (that was supplied with my kit) is the volume of reagent remaining
in the syringe. If you filled the syringe with 1mL of reagent and used 0.52mL then 0.48mL remains in the syringe so your ALK would be 2.97meq/L or 149 mg/L as CaCO3. Check you are using the the table correctly.
You're right of course - I was just reading from my notes......but the number was read off the sysringe and is indeed the remaining amount, not the amount I put in.
adm wrote:I am confused as to whether it is actually measuring total Alkalinity, or Hardness !!!!!!
The Salifert kit you have is almost certainly measuring alkalinity not hardness and not carbonate hardness (as the kit's box implies).
Try following DaaB's alkalinity test kit procedure using the bottle of coloured indicator solution from the Salifert kit and see if you get a similar alkalinity figure. If you have any pH test strips (pH 3.8 to 5.5) then check the pH of the test solution just before and after the colour change. The pH just after the colour change should be ~ pH 4 and the pH just before should be a bit higher. You could also check the pH of your liquor after CRS treatment to check that you are not over dosing.
adm wrote:My water company say the Total Alkalinity figure is 108mg/l CaCO3.
Most water supplies don't have totally stable ALK levels over time, a fluctuation of 25-30 mg/L as CaCO3 is quite possible.
That's kind of what I thought. I'll do some more tests tomorrow and see where I come out. I'm busy patching up leaks in my HLT today, but want to try and get a brew on tomorrow.
As long as the kit test number isn't wildly out of sync with the water company number, I'll use that - it's more likely to be right as the water quality report is over a year old anyway.
Right, did another test and it's 134ml/L CaCO3....so I'll go with that.
Can anyone answer the other question though - after i use CRS to adjust the Alkalinity, should I then add mineral salts in the correct quantities for the 38l of water that I will use, or just for the 23l brew length?
adm wrote:should I then add mineral salts in the correct quantities for the 38l of water that I will use, or just for the 23l brew length?
Simplest and most conservative approach is to treat for post boil volume. The more complicated answer is that it depends upon where you add the mineral salts.
I have always assumed that the target mineral concentrations were for the post boil wort (couldn't say why). I have quite alkaline water which I treat with CRS so I don't need to add minerals to my mash: all mineral salts are added to the boil and I treat for the post boil volume. If you need to add mineral salts to the mash then it gets complicated because some will be absorbed by the grains (proportional to the liquor absorbed by the grains?), some will be lost to the wort in any dead volume in your mash/lauter tun (proportional to the dead volume?) and some may precipitate out and be filtered by the grains (totally unknown amount).
Thanks Mitch.....those are EXACTLY the issues I'm trying to get my head around!
I don't know if I do need to treat the mash water, or just the boil water. I I treat for the brew length in the boil, then I know I've got the right amount of salts in there......but I don't know if they were needed in the mash. If I treat in the mash, then I run the risk of losing a lot of the mineral salts into the grain etc.....
Steve Flack advised splitting the treatment into part mash and part boil, which makes sense to me. Although then there are a lot fo other factors that come into play and are different between the mash part and the boil part. Aargh. That's what I did last time, but I think I did it wrong and dosed for all the water, not for the brew length.
Maybe I'm thinking about this too much....
What i have always done is add my salts to the total water i am going to use, say 42ltrs. I whizz them up in my blender so they disperse easier. I always thought that this would be more practical, but then what do i know
So some clarifaction would be helpful to me also
adm wrote:I don't know if I do need to treat the mash water, or just the boil water
If your mash pH is OK then you don't need to treat the mash, just add all minerals to the boil and treat for post boil volume.
If you need to treat your mash then only trial and improvement will tell you how much you need to add to your mash to get the right pH. As for how to calculate how much of the mineral salts stay in the mash/lauter tun; the only approach I can think of is to assume the mineral salts are washed out of the mash in proportion to the sugars, ie. apply your mash/extraction efficiency to the mineral salts added to the mash to estimate how much makes it into the copper.
adm wrote:Maybe I'm thinking about this too much....
Definitely. Remember that you won't ever spoil a beer by being conservative with the mineral salts.
My water isn't extreme in any way, and my mash pH isn't too far out by itself, and pretty much spot on after CRS treatment.
I'll try treating for the brewlength, all in the boil tomorrow. That certainly has to be the easiest way to go.
OK....so I've been messing around with CRS and the TA test kit a bit more just to put my mind at rest.
I took the earlier 134mg/l CaCO3 test result as gospel, filled the HLT with 46l of tap water and treated it with 30ml of CRS, then tested it again and the test kit result came up as 14.25mg/l CaCO3.
This agrees closely enough with Graham's calculator if I set the target residual alkalinity to 15.
I also did the maths to double check:
Current TA = 134 mg/l
Total Liquor = 46l
Target TA = 15 mg/l
Therefore I need to remove 134-15 = 119 mg/l
119 * 46 =5474 mg CaCO3
Given that CRS removes 180mg per ml, 5474/180 = 30.4 ml CRS required.
Bingo. I'm happy now, and I know that my HLT is now full of 46l of liquor at about 15 mg/l CaCO3, plus a crushed camden tablet and all ready to go for tomorrow morning.
Time for a beer.
Nice one adm!
Have just measured my water here too tonight using the titration method (absolutely brilliant guys) - a mate of mine managed to get me some methyl orange - piles of the stuff too!.
So, finest Thames water (Carterton and Witney) came out at ~10.3ml CRS -> 185mg CaCO3 - using Graham's calculator (also absolutely brilliant!) set with 20 mg residual alkalinity, when treating 40L of water with a "bitter" profile gives me 36ml CRS, 4g gypsum, 9.5g CaCl.
Rock on for tomorrow evening - Marc Ollosons Whitbread Best as the test brew!
Are you adding your salts to the total liquor?
sllimeel wrote:Are you adding your salts to the total liquor?
Yes - I'll make up 40L of it, and then use it for the mash, sparge and topping up during the boil. (for a 5 gallon brew length - should be loads in case I need spare liquor). I think the sparge water should be acidic to avoid the pH rising during the sparge (and hence treating the lot) - I'll test the pH just beforehand and add a few drops of lactic in case it's not.
No. just treat all your water to the correct alkalinity (and add your brewing salts as required) and everything else will look after itself
Cheers Chris, that was what I was hoping will happen
Is it the same deal with darker beers (ie if I leave higher residual alkalinity to cope with the darker grain, do I need to treat the sparge water specially to ensure it is of low alkalinity, or will it just work out using the same alkalinity as for the mash?)
That's brill - thanks Chris. think I'll follow the Brupaks advice and treat according to the beer brewed. My main problems were with pale ales and bitters anyhow, so the main aim for me is to sort those out. Wasn't sure if I'll get much improvement in the darker beers by treating the sparge water separately - I've seemingly not had problems with darker beers in the past when I haven't paid attention to the sparge water, so it'll maybe not be much different if I did.
Thanks for the advice
I finally confirmed what I suspected today, cheers Chris.
Tested 3 samples of water and all came out at 1ml CRS or 18mg/ltr CaC03.
That's what I call a blank template.
Are these kits still available Chris?