Final answer:
Steam Whistle utilizes just spring water and three other GMO-free substances in its brewing process, which aligns with the company's dedication to natural ingredients and the Bavarian Purity Law standards.
Step-by-step explanation:
The statement that Steam Whistle uses only spring water, and three other GMO-free substances in its brewing process is true. Steam Whistle Brewing prides itself on using only four natural ingredients in its beer: spring water, malted barley, hops, and yeast.
They do not use any preservatives, artificial flavorings, or GMO ingredients. This is part of the brewery's commitment to purity and quality in their product, adhering to the traditional standards defined by the Bavarian Purity Law of 1516.