ALT κ-carrageenan, an algae-extracted polysaccharide known for its emulsifying properties, is widely used in food and beauty products. Because of its abundance in nature, similarity to natural glycosaminoglycans, and biocompatibility, it is a promising alternative to animal gelatin for tissue engineering. Key to the more widespread use of κ-carrageenan for biomedical applications is its processability, which is hampered by its temperature-dependent rheological properties. Here, a κ-carrageenan-based ink is introduced that can be 3D printed at room temperature through direct ink writing (DIW). This is achieved by formulating κ-carrageenan as microgels that are covalently crosslinked through a second network, resulting in double network granular hydrogels (DNGHs). These DNGHs can be stiffened through the addition of metal ions and glucose.