1. Heat 25L of Water to 85-90°C
2. Dissolve in 1.2kg of Cane Sugar and 1.2kg Dextrose.
3. Stir in 10g of Fermaid “O” organic yeast nutrient.
4. Begin heating until boiling, then boil for 5 mins.
5. At the end of the boil, dissolve 3.00g of Potassium Bicarbonate into the boiled sugar syrup.
6. Whirlpool the syrup and pour in the 4 bottles of Barkers “Squeezed NZ Lemon and Lime” Syrup
7. Rapidly cool the sugar solution and transfer to fermenter at 18-20°C, oxygenating (either in-line or via aeration in fermenter).
8. Rehydrate and pitch yeast as per manufacturer's recommendations. Ferment at 20°C for the first 4-6 days. As the fermentation slows, increase the set temperature by 0.5°C per day up to a maximum of 22.0°C.

Note:  Additional yeast nutrient (@~0.2g/L) may be required (@ ~1.025) to encourage the fermentation to completely finish. Also, subsequent buffer additions will help maintain the optimal pH range of between <3.5-4.00. These should be dissolved in boiling water and cooled in an airtight container prior to adding to mitigate infection risk.

Fining/ Filtering:

1. 48-72hrs after FG is reached (i.e. No “Buttery” Diacetyl), Crash to 5-6°C.
2. Add preferred finings (Klarsol, Gelatine, etc.).
3. Crash cool to 0-1°C wait for the Seltzer to clear naturally, or filter as required.
4. When fermentation is complete, dump as much yeast cake as possible or transfer off to another vessel.
5. Add additional flavorings/ essences as desired, then carbonate and enjoy!

Notes on Back Sweetening/ Fruit additions:

This is a DRY seltzer. Seltzers made with these simple sugars (Sucrose, Dextrose) should ferment completely dry (0.994-1.000) and not contain any residual sugars. This makes them low-calorie and super refreshing, but fairly tart and acidic. If you prefer something sweeter or plan on adding large amounts of fresh, high-sugar content fruits, pasteurization or preservative addition is likely required to stabilize your seltzer and prevent re-fermentation.

Pasteurization or preservative agents like Sodium Metabisulfite + Potassium Sorbate are commonly used in food and beverage industries as antioxidant/ antimicrobial food additives that, when used correctly, can stabilize the product and prevent refermentation.

Alternatively, you could try your luck keeping the finished product chilled to <4°C at all times, and by drinking it quickly.

The chemistry and technical process for effective Sulfite and Potassium Sorbate stabilization is outside the scope of this Dry Seltzer recipe. For those interested, some great information on the back sweetening process can be found here:

https://morewinemaking.com/articles/SO2_management