pH definitioner - fortynding af en syre - mere afklaring

PH 

PH er en skala, man bruger til at vise hvor stærke syrer og baser er. Ligesom karakterer er en skala man bruger til at vise hvor gode skoleelever er. Forskellen er bare at ph-skalaen går fra 0 til 14, og at det neutrale er 7, i stedet for 8.

Alle væsker med en pH-værdi under 7 er sure, og alle over 7 er basiske, og des længere væk fra pH 7 væsken er, des stærkere er syren (eller basen). En væske med pH 0 er derfor en stærk syre, og en væske med pH 14 er en stærk base.

Hvis fortynder en væske 10 gange, rykker pH tallet en grad tættere på 7. Det vil sige at hvis man tager en milliliter stærk syrer (pH 0) og blander med 9 milliliter vand, bliver det til en pH-1 væske. Hvis man derimod blander syren med 99 milliliter vand, (altså fortynder det 100 gange) bliver det til en pH 2.

Hvis man fortynder en pH 14 base 10 gange bliver det pH-13, og det bliver så igen 12, fortyndet ti gange. En milliliter pH 14, blandet med 999.999 milliliter vand, bliver næsten helt neutralt. Nemlig pH 7. 

Alt det med fortyndingsforholdene er igen noget som det ikke er absolut nødvendigt at lære. Derimod er det vigtigt at vide hvad pH er, og at 7 er neutralt, under er surt, og over er basisk.

Og husk at det kun er væsker der kan have en pH. Alle de andre ting får det først når man opløser det i vand.

Foodgrade - syre/acid - en copy/paste

Tilsætning af syre under mæskning for vandbalance lyder avanceret - ligger dem ind i bloggen ind til videre for at kunne finde dem senere. Tænker at det er interessant med deres respektive reaktion mønstre med saltene i vandet under mæskning.

Dansk for de enkelte syrer med tilhørende teknisk definition

Mælkesyre - C3H6O3

Saltsyre --HCL

svovlsyre - H2SO4

Fosforsyre - H3PO4


Foodgrade syre/Foodgrade Acid

While many acids can be used to accomplish this task only a few have found practical use for water treatment in brewing. Those acids are:

• Lactic acid is an organic acid produced by lactic acid bacteria. To brewers it is available as a 88% by weight solution or acidulated malt. Acidulated malt is pilsner malt that has been sprayed with lactic acid and dried. It contains about 3% lactic acid by weight. Lactic acid may also come from a sour mash or sour fermentation. The latter or acidulated malt is the only acid that can be used for mash and wort pH adjustment in Germany. Narziss reports that the use of lactic acid yields in a smoother beer taste compared to the use of organic acids like hydrochloric acid ^[7]. The anions left behind by lactic acid are lactates which can give the beer a sour twang if used in excess. In my own beers I have used as much as 0.25 g lactic acid per liter of beer which amounts to about 4% acidulated malt in the grist without adverse taste effects.
• Hydrochloric acid (a.k.a muriatic acid) is a strong inorganic acid which replaces the bicarbonate with chloride and, when used in excess, can give the beer a salty taste. The muriatic acid found in hardware and pool supply stores is not necessarily food grade and should be avoided. If food grade hydrochloric acid is available it can be used for water treatment but great care should be taken when handling it. Unlike lactic acid, hydrochloric acid is a strongly caustic acid that readily reacts with almost anything it comes in contact with, including your skin and eyes.
• Sulfuric acid: This strong inorganic acid replaces bicarbonate with sulfate and would therefore be a good choice for hoppier beer styles. It is however even more aggressive and dangerous to handle than hydrochloric acid which is why it is rarely used by home brewers.
• "Phosphoric acid" is a weak inorganic acid that is much saver to handle that hydrochloric or sulfuric acid and is widely used in soft drinks. It replaces bicarbonate with phosphate and therefore increases the phosphate content of the mash. The amount of phosphate added, however, is small compared to the phosphate added by the malt and therefore the use of phosphoric acid should not lead to the precipitation of additional calcium and magnesium