Have I been over-treating my water ?

[Dr Mike]

Recently listened to one of the Brew Strong podcasts on water chemistry and first heard the concept of residual alkalinity. This has made me think I might be over-treating my water.

My starting water usually has an alkalinity (CaCO3 equivalent) of between 80mg/l and 110mg/l - I test every brew day with a Salifert kit. Not sure exact Calcium content but based on the total hardness it is probably in the 50-60 range.

My usual treatment is to reduce the alkalinity down to 30mg/L using AMS/CRS and add about 125mg/L of Calcium using a 60/40 mix of Gypsum and Calcium Choloride.

Now according to John Palmer's Residual Alkalinity spreadsheet (http://www.howtobrew.com/section3/chapter15-3.html - link at bottom of page), I probably only need to be doing one, but not both of these additions for even the palest beers, and for a typical copper-coloured english bitter, I shouldn't really be doing either.

Some of my beers (particularly the Amercian Brown I did recently) do have a slight harshness, almost salty aftertaste about them. Could this be down to too much minerals and/or an over-acidic mash ?

 

[brewtim]

Do you test the mash pH ?

Here is the info from the brupaks website with the calculations, and gives a guide to the ideal ranges, however for CRS it doesn't state what other minerals are added whilst reducing RA. Murhpy's homebrew AMS instruction sheet shows the mineral additions so I'm wondering if these two products are equivalent or not, their calculations for RA reduction are almost exactly the same.

http://www.brupaks.com/brewing-aids.htm

The RA for bitters/pales, stouts and porters and lagers are different and should be higher for darker ales, so you may have reduced it too much if you used the same additions as for the pales.

 

[rpt]

AFAIK AMS and CRS are identical. Originally AMS was only available in large quantities so Brupaks repackaged it for the home brewer, but Murphy now sells AMS in small bottles. I don't know why the instruction sheets don't agree.

 

[Dr Mike]

The AMS I have comes from then The Malt Miller and has a sheet which gives the alkalinity reduction and sulphate & chloride addition for different levels (I'm guessing AMS is a blend of Hydrochloric & Sulphuric acid).

My worry is that using AMS and piling in the calcium could be leading to a mash pH which is too low. I've not measured mash pH. Think I'd need to get a meter as indicator strips would be pretty useless for me due to colour blindness.

 

[chastuck]

The AMS I have comes from then The Malt Miller and has a sheet which gives the alkalinity reduction and sulphate & chloride addition for different levels (I'm guessing AMS is a blend of Hydrochloric & Sulphuric acid).

My worry is that using AMS and piling in the calcium could be leading to a mash pH which is too low. I've not measured mash pH. Think I'd need to get a meter as indicator strips would be pretty useless for me due to colour blindness.

The breakdown of AMS/CRS
100ml is:
• 79.2ml water
• 15.6ml hydrochloric acid,
• 5.2ml sulphuric acid
• giving 64.76 ppm Cl+ & 88.57 ppm SO4+ per 1ml/L
Acid strength is believed to be approximately 20%.

 

[brewtim]

The breakdown of AMS/CRS
100ml is:
• 79.2ml water
• 15.6ml hydrochloric acid,
• 5.2ml sulphuric acid
• giving 64.76 ppm Cl+ & 88.57 ppm SO4+ per 1ml/L
Acid strength is believed to be approximately 20%.

Nice :hat:

You don't happen to know what the breakdown of DWB/DLS is, do you?

 

[rpt]

I asked Google and found this.

 

[Dr Mike]

Thanks for the link. That suggests I'm bang in the range for ordinary bitter. So is the whole residual alkalinity thing a load of twaddle ?

 

[anthonyUK]

RA does exist and this is a nice explanation - http://braukaiser.com/wiki/index.php?ti ... llustrated
How much does it affects your brewing though?
I would say if you are striving for the last few percent of improvements look at this otherwise I'm sure there are better gains to be had in other areas.

 

[Dr Mike]

I probably should have phrased that better!

I'm pretty comfortable with RA in concept. Where the conflicting advice seems to be is in what the right level is. John Palmer suggests that for pale to copper coloured beers you should only get it down to a few ppm either side of zero whilst the Murphy's sheet implies you go much further to around -80ppm.

 

[chastuck]

The breakdown of AMS/CRS
100ml is:
• 79.2ml water
• 15.6ml hydrochloric acid,
• 5.2ml sulphuric acid
• giving 64.76 ppm Cl+ & 88.57 ppm SO4+ per 1ml/L
Acid strength is believed to be approximately 20%.

Nice :hat:

You don't happen to know what the breakdown of DWB/DLS is, do you?

Breakdown of what is in DWB/DLS

From CBA Factsheet No. 1

1g/L of DLS adds:
• 180.77 ppm Calcium Ca
• 5.48 ppm Magnesium Mg
• 75.00 ppm Sodium Na
• 176.92 ppm Chloride Cl
• 370.19 ppm Sulphate SO4

Percentages:
• Sodium Chloride 19%
• Calcium Chloride 13%
• Calcium Sulphate 62%
• Magnesium Sulphate 5%

 

[brewtim]

From CBA Factsheet No. 1

1g/L of DLS adds:
• 180.77 ppm Calcium Ca
• 5.48 ppm Magnesium Mg
• 75.00 ppm Sodium Na
• 176.92 ppm Chloride Cl
• 370.19 ppm Sulphate SO4

Calculating from Murphy's factsheet for DWB, the additions for DLS almost exactly match :thumb: