kristfin wrote:so for pilsen, i should be focusing on the RA and minimizing the sulfate.
Your water is so low in minerals that its RA is only about 16 which you can ignore. Low sulfate is always a good idea where noble hops are to be used. At 2 mg/L you definitely have low sulfate. So the conclusion is to do nothing to this water (but see below).
kristfin wrote:doing nothing but adding 3ml of 88% lactic acid gives me -29 RA and c/s of 20.
Adding 3 mL 88% lactic acid to 40 L of this water would drop the pH to under 4. At pH < 4.3 RA becomes meaningless but if you just stuff the numbers into the equations you would calculate RA of about -7 which if stuffed into the usual formula would cause you to conclude your mash pH would be 0.01 unit less than a distilled water mash or about 5.75 - 0.01 = 5.74. In fact adding 3 mL lactic acid should get you to a reasonable mash pH by the following reasoning:
Assuming you want a 12 °P beer each litre of wort would weigh approximately 1.046 kG and contain 1.046*0.12 = 125.5 grams extract. Assuming you acheive 75% efficiency in mashing that means that you would need 125.5/.75 = 167 grams of malt per litre of wort and for 40 litres thus 6.7 kg. Assuming you want mash pH to be 5.35 and the mash with your water, untreated, comes in at about 5.75 you would try 4% sauermalz (this is a "rule of thumb" - 1% sauermalz for each 0.1 pH drop) for 0.04*6700 = 268 grams. As sauermalz contains, on average, about 1.5% lactic acid that implies that the sauermalz could be replaced by 268*0.015 = 4.02 grams of lactic acid. Your specified 3 mL of 88% acid would give 3.18 grams and is thus in the rough ballpark i.e. a reasonable place to start. Thus procedure would be to dough in with the untreated water, allow some time for thorough wetting, solubilization etc and then add 2 (i.e. 2/3 of the 3) mL of acid to the mash. After a few minutes run a pH check and see if you like the pH. If it is too low, raise to protein rest temperature and then check pH again. If it is still too low, add some chalk. If, on the other hand, it is too high, add more lactic in, say, 0.5 mL increments. With experience you will know what to expect and how much acid you are likely to need. Of course you can add the acid to the water before you mash in but doing it in the mash tun gives you the flexibility to add it incrementally while monitoring pH.
kristfin wrote: i assume that is good for pilsen then. i was under the impression that i should try to get the same c/s ratio as in pilsen water, but hey, what do i know.
For Bohemian Pilsner you would mash in with your water untreated and add sauermalz or lactic acid in order to adjust mash pH. AFAIK that's what they do in the Czech Republic. In that part of the world they are not concerned with chloride sulfate ratio. They just want as little sulfate as they can get. Your water is certainly low sulfate and so you need not worry about this either.
kristfin wrote:with the dortmund water, with your numbers i end up with RA=-8 and c/s 0,26.
RA depends on the definition of alkalinity and the definition of alkalinity is somewhat arbitrary as the analyst is free to choose whatever end point he chooses for the titration as long as he specifies it in the report. . I always assume that is pH 4.3 which gives me an RA of about -8 (so I must have made a typo in the previous post). If I use an end point pH of 4.76 (which is the equivalence end point) RA becomes -10. RA also depends on the pH of your water which I don't know. In any case these levels of RA are small enough that you might as well assume that they are 0.
kristfin wrote:would it be safe for me to say that i'm doing it wrong for pilsen and dortmund since i'm mixing chalk and acid in those, can i assume that my numbers for the rest are more in the general direction, or are those number obviously off
I don't have the time to check them all but in general, if you are adding chalk to brewing water in other than very small quantities you are doing something wrong. In brewing water chemistry the general rule is "alkalinity bad - hardness good". A quick check on the Burton profile shows a lot of chalk that will not dissolve unless acid is added. As your sulfate from Epsom salts is only 50 mg/L sulfuric acid is an obvious choice though enough sulfuric acid to dissolve that much chalk and bring pH to 7, 1.8 mL of 98% acid, would only bring the sulfate to 128 mg/L far shy of what Burton water is like WRT this ion. So here you would need to skip the chalk and add lots of gypsum, which is the source of sulfate in Burton water. If you do this you will have a low carbonate water with high sulfate which should give you decent mash pH without requiring acid (though you should check mash pH and verify this). A glance at the Dublin profile shows incredible amounts of chalk. Again skip this but check mash pH.
Unfortunately there are no simple generalities for setting up brewing water. You need to research each style of beer, understand the water chemistry of the region from which it came and determine which parts of the mineral profile have mostly flavor (sulfate, chloride, sodium, magnesium) effects and which mostly influence mash pH (calcium, magnesium, bicarbonate).
There are lots of places on the web where you can find recipes for water of a particular region (including my website:
http://www.wetnewf.org) based on deionized water (you qualify) but you must bear in mind that putting one of these together going to the trouble of getting the carbonate to dissolve only to have it fall right back out as soon is the water is heated is a waste of time. You should also bear in mind that many of the water profiles that one finds on the web, in books and magazine articles are not valid water profiles which means that they can't exist in nature so you can't synthesize them.
I recommend posting a question here on how to treat the water for each beer as you brew it. You will get feedback from several people with different viewpoints but their recommendations shouldn''t vary that much. Just ignore any that tries to get you to use lots of chalk.
