In the previous story about pH I used tap water to see how much Citric acid I would need to change the pH to a level suitable for beer. I realized that there is not much point to this story if you don’t know what the pH of your water is. Well, to all the people who do not have a pH meter I have some good news: After reading this you will not need one!
Of course you can forget about all of this if you do not care too much about the details. You will still make beer if the pH of the water is not perfect. If you don’t get enough sugar out of your malt just add some sugar afterwards. No problem.
But I can tell from my own experience that the pH does influence the efficiency of the enzymes, resulting in more sugar.
Time for a new experiment.
I got some Turkish waters and measured the pH of these waters. Here are the results:
Sirma 7,4, Erikli 7,9, and Saka mini 8,2
Let’s say that water in general will have a pH between 7 and 8. The pH should be a bit lower for beer making (Between 5,2 and 5,6) so a little acid should be added.
As I wrote before I do not have the acids that beer makers generally use but I have citric acid. Since the quantities are extremely small it will not influence the taste of the beer.
I bought a more accurate scale so I could do measurements a lot more accurate than last time.
The test was as follows:
- I weighed 10 gm of Citric acid
- I dissolved it in a total volume of 100ml
- Of this 100ml I used 20gm. (Containing 2gm acid)
- Add water to 500ml
Now I have a very accurate solution of 2 gm Acid in 500 gm water which is the same as 4 gm/L.
The pH of this solution was 2.8.
Then I threw away 100ml and added tap water to 500 ml. This solution contains 4/5 of the original 1 gm Acid. (1,6 gm in 500 ml = 1.6 gm/l) The pH of this solution is 2,9.
I repeated this until the pH was 8,0 which happened with 0,00618 gm/l citric acid.
Here is the graph that I made from all these measurements. There are a few conclusions:
- You only need very little acid to make the pH drop from 8 to 7. (0,0462 gm per liter actually)
- To reach a pH of 5,4 coming from pH 8 you need 0,220 gm per liter.
- If the pH is low, you need much more acid to decrease the pH even further.
So in conclusion; if you use around 0,2 gm citric acid per liter water the pH is about right for making beer.
Hans
