Homemade ginger beer calculator: a recipe for any batch

How to make ginger beer at home

Homemade ginger beer is a sweet ginger tea that a little yeast turns fizzy in a sealed bottle. The calculator scales our starting recipe, per litre: 30, 50 or 80 g of fresh ginger, 60, 80 or 100 g of sugar, 25 ml of lemon juice, and the starter. Those ratios are a matter of taste rather than a standard, so treat them as a first batch to adjust.

1. Make the ginger tea. Grate the ginger finely, pour over about a quarter of the water, hot, with the sugar, and stir until the sugar has dissolved. Leave it to steep for 30 minutes or so.
2. Cool it. Add the rest of the water cold, then the lemon juice. Wait until it is at room temperature: heat kills yeast.
3. Add the starter and strain. Stir in the strained ginger bug or the yeast mix, then strain out the ginger through a fine sieve.
4. Bottle with a test bottle. Funnel it into bottles made for carbonated drinks and fill one plastic soda bottle from the same batch. Leave a little headspace and cap them all.
5. Squeeze, then chill. Keep the bottles together at room temperature in a closed box or cupboard. Squeeze the plastic bottle at each check; when it is firm, like an unopened bottle of soda, refrigerate every bottle.

Ginger bug or packet yeast?

Packet yeast is quicker and more predictable. Brew Your Own magazine's soda method rehydrates one sachet of champagne yeast in ¼ cup (60 ml) of warm water with ½ teaspoon of sugar and uses 1 teaspoon of that mix per litre; its soda is usually ready to refrigerate after about 12 hours at room temperature, judged by feel rather than the clock.

A ginger bug is a starter you grow from fresh ginger, sugar and water. Our method: stir 2 tablespoons of grated unpeeled ginger and 2 tablespoons of sugar into 250 ml (1 cup) of water in a jar covered with a cloth, and add the same again each day. It is ready when it fizzes as you stir it and smells yeasty. How long that takes depends on your ginger, water and kitchen, and we found no tested day count to quote, so go by the bubbles. Wild starters are less predictable than packet yeast, which is one more reason to rely on the test bottle.

Why the fridge matters: the numbers

Soda-like fizz of 3 volumes takes about 5.9 g of CO₂ per litre, which yeast makes from about 11.5 g of sugar. A medium batch has 80 g of sugar per litre, so only about 14 % of it needs to ferment. If the rest fermented in a sealed bottle too, it would make about 21 volumes, roughly 350 psi (24 bar) at 22 °C, many times what any drinks bottle is made for. At 3 volumes the bottle already holds about 38 psi (2.6 bar).

• Use plastic for the test and bottles made for fizz for the rest. Brew Your Own says to use plastic soda bottles for soda and not glass, because over-carbonated glass can shatter. UF/IFAS says high carbonation needs appropriately pressure-rated bottles.
• Refrigerate as soon as the test bottle is firm, not at a set hour. Warm kitchens get there faster.
• Keep it cold and drink it soon. Cold slows the yeast, it does not stop it; Brew Your Own suggests keeping its soda in the fridge and drinking it within about a day of making it. Open bottles slowly, over the sink.

Is there alcohol in homemade ginger beer?

Yes, a little. The same fermentation that makes the bubbles makes alcohol: by the chemistry, each volume of CO₂ the yeast produces leaves about 0.26 % alcohol by volume, so a batch that reaches 3 volumes in the bottle holds about 0.78 % ABV. In England, the Department of Health and Social Care's guidance on labelling alcohol substitute drinks reserves "alcohol free" for drinks of no more than 0.05 % and "low alcohol" for 1.2 % or less (published 13 December 2018). The government consulted in 2023 on updating those descriptors, including whether drinks up to 0.5 % could be called alcohol-free; as of 5 November 2026 no outcome had been published.

So homemade ginger beer is not alcohol-free. For children, drivers, anyone pregnant or anyone avoiding alcohol, make a ginger soda instead: ginger syrup topped up with sparkling water, which never ferments. The soda syrup calculator scales a ginger syrup and shows the sugar per glass.

Worked examples

• 2 litres, medium, packet yeast: 100 g ginger, 160 g sugar, 50 ml lemon juice (about one lemon), 2 teaspoons of yeast mix and 1.83 litres of water: four 500 ml bottles plus the test bottle.
• 1 US gallon (3.79 L), medium, ginger bug: 189 g ginger, 303 g sugar, 95 ml lemon juice (about two lemons) and 227 ml of strained bug.
• Less sweet: at 60 g of sugar per litre, about a fifth of it ferments for 3 volumes and each 250 ml glass keeps about 12 g of sugar; at the medium 80 g, about 17 g.

Common mistakes

• Bottling only in glass. Without a plastic test bottle you can't feel the pressure building.
• Adding the starter to warm tea. Heat kills the yeast and the batch stays flat.
• Waiting for more fizz "just one more day". Once firm, the pressure only climbs.
• Adding sugar to fix a flat batch and resealing. Sugar is fuel; a stalled batch usually needs warmth or a livelier starter instead.

Serving it at a party? The alcohol-free party drinks planner works out quantities, and Kindred Picnic's party food calculators handle the food.