As much as it would be convenient to have both sides brewing simultaneously, the short answer is no. This is because most dual coffee makers are designed with separate water reservoirs for each side and utilize different brewing processes that wouldn't mesh well when combined. However, there are some exceptions such as the Hamilton Beach FlexBrew which allows you to brew coffee on both sides at once but in different quantities - one side using K-cups and the other using grounds. It's important to note that even though this feature exists, it can still result in uneven brewing and may not yield optimal results.