Fermentation and Beer Production Quiz

The concentration of diacetyl at which it starts to be noticeable to the taste (a flavor threshold).

A type of yeast commonly used in brewing beer to produce alcohol.

Ethanol, carbon dioxide, among other volatile and non-volatile compounds, produced by yeast during fermentation.

Yeast converts sugars into alcohol and carbon dioxide during the process of fermentation

High wort gravity ( Specific Gravity above 1.072) provides a greater potential for alcohol development

Yeast, under stress (e.g. multiple repitches), maybe experience mutation.

Saccharomyces yeast produces alcohol up to a certain percentage but it can be exceeded.

Yeast produces more ethanol during fermentation if oxygen is not present.

The ability of beer to maintain a stable head of foam.

The amount of protein in beer influences the stability of the foam.

Initial points needed for foam bubbles to form in beer.

Consumers judge beer quality based on appearance such as foam stability, before tasting.

Healthiness of yeast cells measured by a special dye.

The most abundant sugar found in wort.

Nitrogen gas decreases the size of bubbles in beer foam.

Adding hops during the brewing process changes the final hop characteristics.

Yeast are more closely related to animals than to bacteria.

Nitrogen gas improves foam stability, size, and mouthfeel, while decreasing bubble size.

Proteins that contribute to beer foam stability, like those from malt (LTPs, protein Z).

The lowest concentration of a substance needed for detection by a person.

Most beer flavor is detected by the nose, not the tongue.

Iso-alpha acids (bitter acids) promote foam and bubble stability in beer.

Ales are made through infusion mashing, while Lagers are made through decoction mashing.

Yeast produce more alcohol through fermentation than through respiration.

Yeast do not metabolize glucose and maltose simultaneously; they metabolize maltose before glucose.

Changes in fermentation temperature affect the amount of esters produced by yeast.

The size of nucleation sites (the initial points of bubble formation) impacts bubble size during fermentation.

Yeast contributes Proteinase A; malt contributes hordeins, protein Z, and LTP (lipid transfer proteins) to foam formation.

Tetra iso-alpha acids can impair the appearance of beer foam.

LTP and Protein Z are water-soluble proteins, classified as albumins.

Water, hops, malt, adjuncts, and yeast contribute directly to beer flavor.

Cans provide complete protection against the formation of MBT, a compound responsible for a skunk-like aroma in beer.

A buttery or butterscotch-like flavor in beer produced by yeast during fermentation.

Some yeasts have the ability to break down the sugar maltotriose, which is a significant sugar in wort.

Fermentation produces more than just ethanol, other alcohols are also present.

These compounds contribute to the aroma and flavor of beer. They include higher alcohols, sulfur compounds, organic acids, and VDKs.

During fermentation, one molecule of glucose is converted into two molecules of ethanol and two molecules of carbon dioxide.

It's possible to make an ale style beer using a lager yeast strain.

Using the same yeast culture multiple times.

Brewers typically use different strains of Saccharomyces yeast for brewing ales and lagers.

Yeast prefers certain amino acids for growth, proline is the least preferred.

Yeast are more closely related to animals than bacteria.

Organic acids released by yeast during fermentation lower the pH of the beer.

Nitrogen gas improves foam stability, size, and mouthfeel, but reduces bubble size.

The lowest concentration of a substance that can be detected by taste.

Most of a beer's flavor is detected through the nose, not the tongue.

Ales are made through infusion mashing, while Lagers are made through decoction mashing.

Yeast metabolize maltose before glucose during fermentation.

Proteins in beer influence foam stability, with some enhancing it and others hindering it. Foam-stabilizing proteins keep out those that are less foam-friendly.

The amount of carbon dioxide present influences the surface tension of beer, affecting the formation and stability of foam.

Proteinase A, an enzyme produced by yeast, enhances foam stability in beer.

The relationship between protein content and foam stability is not linear, but rather follows a positive exponential curve. Higher protein content initially leads to greater foam stability, but eventually, it plateaus.

The typical radius of a foam bubble in beer is approximately 0.5 mm.

For a bubble to form, it needs a starting point, called a nucleation point. This can be anything from a scratch on the glass to a speck of dust.

The temperature of beer influences its foam characteristics. Generally, colder beer creates a more persistent foam.

Nucleation sites, like scratches on the glass, are responsible for 'beading' in beer. This is the constant formation of tiny new bubbles that replenish the foam.

Higher hydrogen ion concentrations (lower pH values) in beer are associated with increased sourness.

The process of reactivating dried yeast by adding water before adding them to the wort.

Higher gravity wort doesn't necessarily mean faster fermentation.

Yeast can metabolize sugars larger than disaccharides; they can even metabolize some trisaccharides.

Zinc is a key mineral that enhances yeast metabolism during fermentation.

The size of the initial bubble formation points (nucleation sites) influences the overall size of the beer foam bubbles.

Malt provides hordeins, protein Z, and LTP (lipid transfer proteins), while yeast contributes Proteinase A, all of which influence foam.

Tetra iso-alpha acids, a type of bitter acid, can negatively impact the visual appearance of the foam.

Smelling beer through the back of the throat, giving an additional dimension to the aroma.