Astra Red Cream Soda Hard Seltzer Recipe

Sanitize and prepare

Sanitize all vessels, stirring spoon, airlock and fermenter. Use a food-grade sanitizer and rinse if required.

Heat 3 L of the fermenting water to about 60–70°C. Dissolve all of the neutral fermentable (dextrose/corn sugar) into the warm water, stirring until completely dissolved. Do not boil — heat just enough to dissolve and sanitize the sugar solution.

Cool the sugar solution to room temperature (18–25°C). Top up with the remaining ~5 L of chilled, sanitized water to reach approximately 8 L total ferment wort. Check temperature to ensure it is below 25°C before pitching yeast.

Add yeast nutrient and pectic enzyme (if using) to the cooled wort and stir well to incorporate.

Pitch the champagne yeast packet into the wort and stir to evenly distribute. Fit an airlock and place the fermenter in a stable location at 18–22°C.

Allow primary fermentation to proceed for 5–10 days or until gravity reaches target (typically near 1.000–1.002 for a sugar-only ferment). Fermentation may be fast with champagne yeast — monitor for activity and final gravity.

When fermentation is complete and gravity is stable over 48 hours, rack (transfer) the clear seltzer off the yeast lees into a sanitized secondary vessel if desired to improve clarity.

If using gelatin: hydrate 1 tsp gelatin in 30 ml cold water for 5 minutes, then gently warm to dissolve (do not boil). Add dissolved gelatin to the cleared seltzer and hold cold (near 2–4°C) for 24–48 hours to settle haze. If using a vegan clarifier, follow that product's instructions.

If you plan to stabilize the product against re-fermentation (for sweetened finished beverage), add potassium sorbate according to package directions (0.5 tsp is given here as a guideline) after racking and prior to flavoring/sweetening. Note: potassium sorbate is only effective when yeast is not active; do not add before fermentation is complete.

Prepare the flavor blend in a small sanitized container: combine 20 ml natural strawberry concentrate, 5 ml vanilla extract, 5 ml cream soda concentrate (or marshmallow/vanilla candy flavor), 2 ml of 5% citric acid solution, and 1 ml red food coloring if desired. Mix thoroughly and taste a small diluted sample (1 part flavor blend to 40 parts seltzer) to check balance.

Adjust the flavor: increase strawberry in 2–5 ml increments if more fruit character is desired, add up to 2–3 ml more vanilla if a richer cream note is needed, and adjust citric acid by 0.5–1 ml steps to achieve a bright but not sharp acidity. Keep notes of adjustments.

Once the blend is to your liking, gently add the flavor blend to the clarified seltzer (approx. 8 L). Stir gently to homogenize — avoid vigorous agitation that would strip CO2 if already carbonated. If stabilizer (potassium sorbate) was added, ensure proper mixing now.

Optionally, pasteurize flavored product for shelf stability: warm the filled bottles/cans slowly to 60–65°C for appropriate time per your pasteurization schedule (follow safe pasteurization guidelines) or use cold-fill with reliable preservatives and refrigeration.

If force-carbonating: transfer the flavored seltzer into a keg and carbonate with CO2 at 2.5–3.5 volumes of CO2 (typical for a soda-like mouthfeel). Chill to near 2–4°C and apply pressure per your equipment to reach the target volumes (approx. 30–35 psi at 2°C for many systems).

If bottling with CO2 or cold-fill carbonated water: pre-carbonate cold water or beverage to desired carbonation and blend carefully. Fill sanitized bottles or cans with cold carbonated seltzer, leaving minimal headspace, and cap immediately to preserve carbonation.

If bottle conditioning (not recommended for sweetened flavored seltzer due to continued fermentation risk): add an appropriate measured priming sugar and bottle. Store at controlled temperature and monitor for over-carbonation. This recipe assumes force-carbonation or cold-fill.

Chill finished packaged Astra Red Cream Soda Hard Seltzer before serving. Serve cold in a chilled glass over no ice to preserve carbonation and flavor.