Bacteria

Question 1

Below what pH do coliform bacteria not propagate?

Answer 1

Coliform bacteria do not propagate in hopped wort with a pH below 4.7

Question 2

What off flavors are produced by coli-aerogenes?

Answer 2

Celery taste and odor is produced by coli-aerogenes. Other flavors are ‘earthy’ or ‘smoky’; milder cases can be a fairly pronounced after-bitter. Therefore, brewery water should be periodically tested for coli-aerogenes group of bacteria

Question 3

Yeast pitching

Answer 3

Promptly pitching fresh and healthy yeast into the wort helps avoid developing off-flavors. But a badly infected wort will still suffer.

Question 4

What are the four odors associated with water containing bacteria?

Answer 4

Aromatic odor resambling flowers and vegatables: geranium, nasturtium, violet, muskmelon, and cucumber. Can be attractive or objectionable, e.g., skunky or gralicky.

Fishy odor - clam shell, cod-liver oil, seaweed, irish moss, rockweed, and salt march.

Grassy odor

musty or earthy odor including potato bin or moldy or swampy

Question 5

Odors that could be from chlorine or algae

Answer 5

Chlorophenolic, iodoform or medicinal odors could be produced by chlorine or algae

Question 6

What do active carbon filters remove?

Answer 6

Active carbon will remove odor and flavors along with the absorption of some of the soluble substances in water