What happens if you overdose the CRS?

[simple one]

Not that I have! Or think I have at least.

I have searched and searched.... What are the negative effects of taking the residual alkalinity down below 20mg/l? And what happens if you drop to 0mg/l or add CRS on top of this?

Cheers in advance.

[WallyBrew]

Not that I have! Or think I have at least.

I have searched and searched.... What are the negative effects of taking the residual alkalinity down below 20mg/l? And what happens if you drop to 0mg/l or add CRS on top of this?




Cheers in advance.

If you lower the alkalinity whilst all other things remain constant the pH of the mash should be lower however, this is probably initial and if the pH is measured again later into the mash then it will be seen to rise by 0.1 to 0.2 units.

Deliberately acidifying the mash will lead to loss of extract, much lower attenuation, lower colour and increased soluble nitrogen although the latter will decrease if the pH is shifted much below 4.6

The above applies to infusion mashing and not decoction.


Due to the lack of a table function you'll have to put up with the cobbled version.

Code: Select all

From - Hopkins, Journal of the Institute of Brewing 1925, 31, 399

pH of wort       extract brewers lbs / qtr       maltose g/100g of malt       alcohol % vol
   6.00                  88.4                             48.6                     4.68
   5.40                  89.9                             49.8                     4.95
   5.15                  90.3                             48.6                     4.61
   5.10                  89.6                             45.6                     4.08
   4.80                  89.2                                -                     2.21
 

[/size]
The results in the above table are from an infusion mash at 150F (I.o.B. method) though by the alcohol content it was mashed at a rate greater than 50g to 515ml
The extract is given in brewers lbs per quarter. This is what you would theoretically get if you mashed one quarter of malt (336lb) with one barrel liquor (360lb) To convert to sg add the extract to 360 and divide by 360, so for the first one (88.4 + 360) / 360 = 1.2455.

Note that the pH is that of the wort and at initial mash may have been different.

[simple one]

Thanks both of you....

So to some up:

1. You could taste the acidic nature of the CRS in the final beer.

2. Extract from the malts may be less.

3. Yeast attenuation should be reduced.

4. Colour may be altered and haze may be introduced.

[simple one]

Ok.... so is a good indication of whether I am doing all this water treatment well.... to measure the pH of the final beer?

What should it read?

[simple one]

In fact got this from a malt site:

pH of Beer

General Considerations
• Beers with a high pH are prone to infection by micro-organisms.
• Variation in beer pH can reflect inconsistency in fermentation.
• Problems may be encountered when beers of pH outside the normal range are fined.
• Problems may be encountered with flavour if the pH is outside the normal range.

Range of Values
• The acceptable range of pH for cask conditioned beers is 3·7 - 4·1 units (see also Topics 3 and 11).
• For a given brand the pH should not vary by more than ± 0·15 units

Operational Protocols
• The pH value of every beer should be taken at rack.
• Beers of very low (acid) pH should be checked for acidity produced by contaminating micro-organisms.

Measurement Protocols
• Beer should be degassed prior to measurement of pH.
• pH measurement to ± 0·1 units requires daily calibration of the pH meter and either a fixed temperature for measurement or automatic temperature compensation.

Which sort of says it all really!

[simple one]

Cheers Wally and Chris. Thats answered alot of questions.

I also wondered if this alkalinity business was the reason why some types of beers attenuate better than others for certian brewers. I guess it may have a hand in it....

Matt

[WallyBrew]

Some light reading for you. http://rims-brewing.tripod.com/Documents/38_1_1.pdf

The fish bone diagram on page 4 is quite good

[simple one]

Fantastic, cheers Wally, thats great reading.

Thanks Chris and Wally, its one of those things that you know is wrong to do, but no one ever tells you exactly why.

Cheers.