As an expert sommelier and brewer, I can provide you with some insights into Yuengling's brewing process and the use of corn syrup. It is important to note that my answer is based on my knowledge and understanding, and may not reflect the current practices of the brewery.
Yuengling is known for its traditional brewing methods, and while they do use adjuncts like corn in some of their beers, they do not use corn syrup in their brewing process. The use of adjuncts, such as corn, is common in American lagers to lighten the body and add fermentable sugars.
During the brewery tour, it is possible that they showcase a bottle of crystal malt and corn grits as examples of ingredients they have used in the past or could potentially use in experimental brews. However, it is likely that they have moved away from using these specific ingredients in their regular production.
Instead of corn grits, Yuengling uses a caramelized corn syrup, which comes in large 50-gallon barrels. This syrup serves as a source of fermentable sugars and can contribute to the flavor and color of the beer. It is important to note that corn syrup is different from high fructose corn syrup (HFCS), which is commonly used in processed foods and beverages.
Using corn syrup as an adjunct is a common practice in the brewing industry, as it provides a readily available source of fermentable sugars. However, the use of corn syrup should not be confused with using corn grits or other whole corn products in the brewing process.
It is worth mentioning that the use of adjuncts in brewing is a topic of debate among beer enthusiasts. Some argue that the use of adjuncts like corn or rice can negatively impact the flavor and character of the beer, while others believe that when used skillfully, adjuncts can enhance the overall drinking experience.
In my personal experience, I have tasted beers that use corn syrup as an adjunct, and while it can contribute to a lighter body and slightly sweet flavor, it does not necessarily detract from the quality of the beer. Ultimately, it comes down to the brewer's skill and intention in using adjuncts.
To summarize, while Yuengling does use adjuncts like corn in their brewing process, they do not use corn syrup as showcased on their brewery tour. Instead, they may use a caramelized corn syrup for fermentable sugars and flavor enhancement. The use of adjuncts in brewing is a common practice, and when used skillfully, it can contribute to the overall character of the beer.