Wort Composition

Question 1

What is the primary composition of wort?

Answer 1

Wort is composed of:
* Carbohydrates: 90-92%
* Nitrogenous compounds: 3-6%
* Lipids: 0.2-1.0%
* Polyphenols: 1.5-2.0%
* Inorganic material: 1.5-2.9%
* Vitamins: 0.05%

The composition can vary based on the mashing regime and adjuncts used.

Question 2

What are the main types of carbohydrates in wort?

Answer 2

Wort carbohydrates mainly consist of:
* Products of starch degradation
* Breakdown of pentosans and β-glucans

Typical wort is around 75% fermentable.

Question 3

What are the fermentable sugars in wort and their approximate proportions?

Answer 3

The fermentable part of wort comprises:
* Maltose: 67%
* Maltotriose: 20%
* Glucose: 13%

Small amounts of fructose and sucrose are also present.

Question 4

What are the negative effects of proteins in wort?

Answer 4

Negative effects of proteins include:
* Wort separation and filtration problems
* Haze formation in finished beer

Proteins can promote foam stability but have these drawbacks.

Question 5

What are the four types of nitrogenous compounds in wort, listed in descending order of size?

Answer 5

The four types are:
* Proteins
* Polypeptides
* Peptides
* Amino acids

Amino acids make up 10-15% of the wort’s total soluble nitrogen.

Question 6

What is the role of amino acids in wort?

Answer 6

Amino acids are essential yeast nutrients and part of FAN, with 140-160 mg/L required at the start of fermentation

FAN stands for Free Amino Nitrogen.

Question 7

What are the primary forms of lipids present in wort?

Answer 7

Most lipid material in wort is in the form of:
* Free fatty acids
* Sterols

These are important yeast nutrients for consistent fermentations.

Question 8

How do polyphenols affect the beer?

Answer 8

Polyphenols can:
* Form trub and haze with polypeptides
* Affect the mouthfeel of beer

Their levels increase with higher pH and mashing temperatures.

Question 9

Which inorganic ions are required by yeast as growth factors?

Answer 9

Required inorganic ions include:
* Zinc
* Manganese
* Calcium
* Magnesium
* Sodium
* Potassium
* Iron
* Copper
* Phosphate
* Sulphate

Zinc is often added to wort as it may be insufficient in malt.

Question 10

What vitamins are found in wort that are necessary for yeast?

Answer 10

The vitamins required by yeast include:
* Biotin
* Pantothenate
* Myo-inositol
* Thiamine
* Pyridoxine
* Niacin

These vitamins serve as enzyme cofactors.

Question 11

True or False: Adding zinc to wort is permitted by the Reinheitsgebot.

Answer 11

False

Some brewers use zinc components in vessels to leach zinc into the wort.

Question 12

Fill in the blank: The non-fermentable part of wort is mostly composed of _______.

Answer 12

[polysaccharides]

These are produced from starch and cell wall material during mashing.