Do Try This At Home | Ginger Beer
Make a classic low-alcohol drink at home. Perfect for sunny weather.
Welcome back to Do Try This At Home - our series of super-fun weekly science activities.
Our building is closed right now, but that doesn't mean we can't do some science at home.
Here's a question for you to think about - Why do you drink drinks but not food food?
We love a bit of fermentation in the We The Curious kitchen. There is something pretty awesome about harnessing the power of tiny microbes to make something delicious. Loads of our favourite foods USE microbes.
You will need:
- Large plastic (PET) bottle or a glass bottle with bubble valve (DO NOT use an airtight glass bottle unless you are certain that it has been manufactured for brewing)
- Sharp knife and chopping board
- Mixing bowl
- Tea towel or cloth
- Sieve or strainer
- (Optional but useful) Funnel
- (Optional) Grater or food processor
- About 500g root ginger
- 350g sugar (brown or white, we’ve also tried a mix of both)
- 3l water
- (Optional) Spices and other flavourings e.g. lemon, lime, chilli, bay leaves, cinnamon
These quantities will make 3l ginger beer. Adjust as necessary (e.g. for one 500ml drink bottle, divide all quantities by 6)
A note about the alcohol content of ginger beer. It’s very difficult to measure the exact alcohol content of homemade ferments. This recipe will typically come out somewhere between 0.2% and 1% ABV depending on temperature and starting conditions; that's too low to cause intoxication in most people, including children of an appropriate age. If you're avoiding alcohol completely for any reason, this might not be the drink for you.
- Thoroughly wash all of the equipment with boiling water to avoid contamination.
- Peel the ginger and either grate it, finely chop it or whizz it in a food processor.
- Add the shredded ginger, sugar and water to a mixing bowl along with any other spices or flavours (we used chilli, lemon and lime).
- Mix to dissolve the sugar and pour into plastic bottles. Leave at least 3cm of air at the top of the bottle. Screw caps onto the bottles.
- Leave in a dark place to ferment for 24-36 hours, check about every 8 hours to see if the bottle is filling with gas. If it feels firm, open the lid briefly to let out excess gas. (If you’ve got a big bottle or large jar with a valve, you can do this step all in one container.
- Strain the ginger beer through the sieve back into a clean bowl to remove any pieces of ginger or spices. Return the liquid to the bottles and leave to ferment for another 24-36 hours. This time, don’t release excess gas as we want our ginger beer to be nice and fizzy.
- Once the bottles feel firm, they are ready to drink. Put them in the fridge to stop any additional fermentation. They can be stored this way for up to a week.
Tips and ideas
- An alternative method is to add yeast during step 3. Our recipe relies on using the naturally occurring yeast and microbes in our environment. If you add extra yeast, this can help speed things up a bit but things will happen a bit quicker. Make sure to leave each stage of fermentation for 24 hrs max.
- The longer you leave the bottles, the more sugar will be converted by microbes. Less time means that your drink will be sweeter and less fizzy. More time means a higher alcohol content and more fizz. Experiment with different timings and see what works for you.
- Try some different flavours. You could add spices like cloves or herbs like rosemary. What if you used pineapple instead of ginger?
Though humans have been flavouring drinks with ginger for at least 2000 years, the first mentions of fizzy ginger beer don’t appear until the 1700s when brewers in Yorkshire created an alcoholic fermented ‘ginger beer’.
Bristol also has an interesting part to play in this story. Before the 1800s, fizzy drinks like ginger beer were difficult to store and transport. They would go flat and, because of their high sugar content, go off quickly. In 1835, bottle makers in Bristol developed an improved glazing process that allowed the creation of stronger, airtight bottles. This meant that ginger beer could be stored for much longer and shipped all around the world.
How does it work?
Although we are only adding three ingredients to our bottle: water, ginger and sugar, we are actually, secretly, adding something else really important: microbes.
Even though we made sure to clean everything thoroughly, there are tiny microbes living in the air, inside the ginger and water and even on our hands. As the ginger beer sits in the bottles, these microbes, particularly yeast, will be feeding on the sugar and converting it to a gas called carbon dioxide and a small amount of alcohol. This is what makes our drink fizzy!
Why doesn’t it go mouldy?
There are lots of different kinds of microbes, some are harmful to humans, some cause mould and many are actually pretty useful. If everything goes to plan, we aren’t introducing too many microbes in the first place. Also, most of the harmful ones (unlike yeast) need oxygen to multiply; by keeping the bottles sealed during fermentation and storage, we are creating a low-oxygen environment where the harmful microbes can’t multiply.
If you do get mould or your ginger beer smells ‘off’, you shouldn’t drink it. Just get everything nice and clean and give it another go.