1. Appearance: colorless and transparent, without suspended solids and sediments.
2. Taste: It has a refreshing taste. No salty, bitter, astringent and other odors.
3. pH value: 6~7 is appropriate.
4. Hardness: the total hardness is less than 8˚, and the temporary hardness is 2˚~5˚.
5. Organic matter: the consumption of potassium permanganate should be 0~3mg/L.
6. Total dissolved salts: the content of solids should be 150~200mg/L.
7. Iron salt: preferably no more than 0.3mg/L. The presence of iron salts will oxidize the tannins in the wort, increase the color of the wort, and make the beer with an iron smell and prone to turbidity.
8. Manganese salt: below 0.1mg/L is better. Trace amounts of manganese salts are good for yeast growth, while excessive amounts can make the beer dull and harsh.
9. Silicate: in terms of SiO3, it should be below 30mg/L. Excessive amount will make the wort unclear, form micelles during fermentation, affect fermentation and beer filtration; cause beer colloid turbidity; make beer taste rough.
10. Other metal ions: The content of heavy metal ions must meet the drinking water standards. Excessive inhibition of yeast and enzyme activity and early cloudiness of beer is also harmful to human health.
11. Calcium sulfate: 1~1.5g/L is appropriate.
12. Chlorine and chlorides: The chlorine content should not exceed 0.3mg/L. The optimum content of chloride is 20~60mg/L.
13. Nitrogen compounds: nitrates should be below 0.2mg/L. Nitrite and ammonia nitrogen are preferably not detected.
14. Harmful microorganisms: cultured at 37°C for 24 hours, the total number of bacteria in 1mL of water should not exceed 100, and there should be no Escherichia coli and Streptococcus.
