Why did farmers rely on whiskey as a main product to sell

Farmers relied on whiskey as the main product to sell because generated a greater income for the farmers. They earned more per liter than they did when they sold the grain to buyers.  In other words, it was more profit-intensive. Grain was also difficult to transport to the market while whiskey  was easier to transport to the market.  The farmers who distilled the whisky used to barter with the whisky - it acted as a currency. Farmers traded whiskey for the goods they needed.