When considering High Gravity Brewing in your brewery operation, it’s necessary to understand the pros and cons of it, in particular concerning beer quality.
Can smaller breweries use High Gravity Brewing to increase output without significantly increasing capital costs? If so, what options and techniques are available to breweries to increase production without substantially increasing capital costs?
Large breweries often use high gravity brewing to maximize brewery throughput, as in the amount of beer you can make, without adding more tanks, i.e., decreasing capital costs.
Is it, however, something you would consider to be craft? There are two ways to approach the problem, so let’s look at those.
What exactly is a High-Gravity Beer?
The term “gravity” refers to the number of fermentable sugars present during the brewing process of beer. More sugar means more food for the yeast to consume and convert to alcohol.
Brewers measure the gravity of the unfermented ingredients before adding yeast. The original gravity of the beer is represented by a number such as 1.061 or 1.080, and the higher the gravity, the higher the potential alcohol content of the beer.
Brewers constantly check the gravity of the beer during the brewing process to ensure consistency. After fermentation, they measure the beer’s final gravity and compare it to the original. The difference between the two figures represents the amount of sugar converted into alcohol.
- Increased percentages of fermentation and finished attenuation
- High-quality yeast viability and vitality
- Reduced production times, as well as novel yeast strains
- Improved beer stabilization and filtration
- improved beer quality and consistency
For the past 40 years, high-gravity brewing has been gradually introduced into breweries worldwide. It is a process that uses wort (unfermented beer) at higher concentrations than usual and, as a result, requires dilution with specially treated water (usually de-oxygenated) at a later stage in the process to achieve the desired gravity or alcoholic strength.
Increased production demands can be met without expanding existing brewing, fermentation, and storage facilities by reducing the amount of water used in the brewhouse.
The high-gravity brewing process also has several cons. Brewhouse material credibility (the extraction efficiency of soluble material from malt and other cereals used in the process) is low due to the more concentrated mash.
Also, hops declined during the wort kettle boil; the final diluted beer exhibits reduced foam stability, and flavor variations have also been encountered. Due mainly to the more concentrated wort and the increased ethanol production, Yeast performance can be adversely affected by high-gravity worts. It can contribute to several aspects of beer stability.
Changes in yeast intracellular morphology have been observed, particularly in the yeast cell vacuole.
Beer stability (or instability) can be considered within six categories: physical (colloidal), flavor, foam, light, biological, and gushing. Because of high-gravity brewing procedures, the first three categories have been implicated in beer quality. High-gravity-brewed beers are more physically stable compared to their lower gravity-brewed counterparts
High-gravity brewing is not a problematic technique, but the yeast must be treated carefully since it will be expected to function in a more stressful environment.
Although there are some drawbacks (effects on beer stability, flavor match, hop utilization, and so on), the benefits outweigh the drawbacks (increased brewing capacity, reduced utility costs, more alcohol per unit of fermentable extract, improved physical and flavor stability).