The best containers are freezer-safe glass, silicone or plastic containers. You can also use stainless steel containers with airtight lids. One of my favorite freezer-safe containers is Weck glass containers. They can be used for everyday food storage or for canning. My other favorite is Souper Cubes (Affiliate Link) freezer storage containers. You can store in smaller portions and use as needed. You should avoid reactive metals, like aluminum, copper, and cast iron. They react with the acid in the chutney and can give the chutney an unpleasant metallic flavor.