Basic Knowledge of High Gravity Beer
High-gravity beer, also known as “big beer,” is characterized by its bold, flavorful, and powerful body. With its strong taste and other exaggerated characteristics, as well as higher alcohol content (which varies by law and from state to state), high-gravity beer is truly substantial.
The term “high gravity” refers to brewing beer with a high original gravity (OG). Generally, beer with an OG above 1.075 is considered high-gravity beer. OG measures the fermentable and non-fermentable substances in the wort before fermentation. It is measured after the initial boiling and before the yeast is added, and is later used with the final gravity reading to calculate the alcohol content.
A higher OG indicates that there is a lot of “food” in the wort for the yeast to consume. When yeast consumes this delicious “food,” they produce alcohol as a result. Under appropriate environmental and care conditions, certain yeast strains in high specific gravity wort can produce a significant amount of alcohol. This is why “high specific gravity” and “high alcohol content” are synonymous.
Common Styles of High-Gravity Beer:
– Barley Wine
– Imperial Porter / Imperial Stout
– Scotch Ale / Wee Heavy
– Imperial IPA
– Wheat Wine Ale
– Barrel-Aged Beer
– Belgian-Style Golden Strong Ale
Factors to Consider When Brewing with High Gravity
The principle of high-gravity brewing and dilution is no secret to professional brewers, but it can be challenging for homebrewers who are ready to try this method. Here are a few key points to keep in mind before proceeding with high-gravity brewing.
Dilution Point
Extract brewers should be familiar with the concept of dilution. Almost every extract brewer boils the concentrated wort and then transfers it to a fermenter with a small amount of water to speed up the cooling process. Additional water is added later to reach the final batch volume.
Style Restriction
High-gravity brewing is only recommended when producing medium-strength beers or higher. Strong beers like barley wines and Doppelbocks rely on the gravity obtained from the wort, and diluting these beers can be counterproductive. Additionally, the alcohol tolerance limit of brewing yeast makes it practically impossible to brew ultra-high-concentration beer for dilution and production of high-alcohol finished beer.
Dilution Limit
If you have ever visited a large commercial brewery, you may have tasted their undiluted beer samples. While professional brewers can brew excellent beer, diluting it with water weakens its flavor. In the commercial brewing industry, the general rule of thumb is that beer can be diluted up to 30-40%. Considering this range as a practical limit, adding less water will have minimal effect on the final product. By adjusting the formula appropriately, adding 10% water to the beer will not significantly impact its quality but will greatly improve production efficiency.
Good Water Makes Good Beer
The water used for diluting beer must be sterile and free from unwanted elements such as chlorine, oxygen, and minerals. Oxygen in the water can oxidize compounds in the finished beer, reduce its shelf life, and create off-flavors. Boiling the water effectively removes oxygen. Carbonated water is ideal for diluting beer because it lacks oxygen and does not dilute carbonic acid in the beer. Be sure to read the label carefully, as some carbonated water may contain sweeteners, salt, or other undesirable ingredients. If the beer is carbonated during bottle or keg fermentation, carbonated water is unnecessary.
Other Considerations
High-gravity brewing requires a higher amount of raw materials, including more malt, hops, and yeast. It also presents new challenges for brewers. Studies have shown that high-gravity beer, regardless of dilution, has poor foam retention compared to regular gravity beer. Additionally, the high gravity environment can lead to reduced hop utilization and poorer yeast performance. The color of high-gravity beer is usually dark and may need adjustments. Fortunately, these problems can be addressed by adjusting the recipe.
Advantages and Disadvantages of High-Gravity Brewing
Advantages
– High-gravity brewing reduces water consumption in the brewery and can meet increased production demands without expanding existing brewing, fermentation, and storage equipment.
– When processing small amounts of wort while maintaining a constant liquid output, it can improve energy efficiency.
– High-gravity brewing allows for greater flexibility in the types of beer available for sale. Brewers can produce many different products with varying original extracts and alcohol contents from a single high-strength beer, eliminating the need to maintain separate inventories for each beer type.
– With the emergence of hop extracts, malt extracts, syrups, and natural pigments produced using carbon dioxide and ethanol as solvents, the range of marketable beer types has expanded further.
Disadvantages
– The use of higher wort concentrations reduces the brewhouse’s production efficiency, resulting in lower extraction of soluble materials from malt and other grains.
– The utilization of hops decreases during wort boiling, and the final diluted beer exhibits lower foam stability and potential changes in flavor.
– Higher wort concentrations and increased ethanol content may affect yeast strain performance.
– High-gravity brewing is not a difficult brewing technique, but yeast must be handled with care as they work in a more stressful environment.
– Although high-gravity brewing has drawbacks such as influences on beer stability, flavor matching, and hop utilization, it also has numerous benefits like increased brewing capacity, reduced utility costs, higher alcohol content per unit extract, and improved physical and flavor stability.
