Yes, you can use pre-ground coffee for cold brew, but you may not get the best results. Cold brew is a method of making coffee by steeping coarsely ground beans in cold or room temperature water for several hours. This results in a smoother and less acidic coffee that has more flavor and aroma than hot brewed coffee. However, pre-ground coffee is usually ground for drip machines or other methods that require a finer grind. This means that pre-ground coffee may over-extract or become bitter when used for cold brew. Therefore, it is recommended to use coarsely ground coffee or grind your own beans for cold brew.