How to Make Cold Brew with the Adventure Flask

Cold brew is a good plan for a morning when you want to get moving. Make it the night before, then take the finished drink with you. This is Julie Bacon’s oat-milk-and-cinnamon routine, updated with clearer steps for the All-Day Adventure Flask.

What you need

• The clean Adventure Flask and its Filter Basket setup.
• Coarsely ground coffee and cold drinking water.
• Optional for serving: about ½ cup oat milk, a dash of cinnamon, and honey or syrup to taste.

The full Flask kit includes the Filter Basket. Coffee, water and milk are separate. If this is your first time assembling the kit, use the Flask getting-started guide alongside the steps below.

Make the cold brew

1. Add coffee. Julie’s original starting point is to fill the Filter Basket roughly halfway with coarse grounds. Keep the grounds inside the basket, not loose in the bottle.
2. Assemble the cold-brew setup. Secure the basket in the appropriate connector/strainer configuration and attach it to the Flask as shown in Hibear’s instructions. Check that every part is seated before adding water.
3. Add water and refrigerate. Pour in cold drinking water without overfilling the bottle. Close it and refrigerate for 10–12 hours, the steeping window Julie uses. Your preferred strength may differ; adjust the grounds or time on the next batch.
4. Remove the grounds. Take out the basket before serving. Keep used grounds contained for disposal and clean the basket after use. If you want to use the Thermal Core for the finished drink, switch to that setup only after removing the basket.

Make it yours

Pour the cold brew over ice, or add oat milk, cinnamon and a little sweetener. Honey can be slow to mix into a cold drink, so stir it in well or use a syrup you like. For Julie’s “wake and shake” version, remove the grounds, add the mix-ins, secure the cap and shake the cold, noncarbonated drink. Never shake a hot drink or carbonated liquid in a sealed Flask.

There is no single strength that suits everyone. If the first batch is too strong, dilute your serving; if it is too light, adjust the next batch rather than packing more grounds into an already-full basket.

Before the next batch

Empty the grounds, then wash and dry the Flask and the parts you used according to Hibear’s care instructions. Clean the connector and basket especially well when you have added milk or sweetener. Prepare the next batch with fresh water and coffee.

Want to see the setup? Watch Hibear’s original cold-brew demonstration below. For the complete bottle and brewing components, explore the All-Day Adventure Flask.