Wednesday, May 09, 2012

Ginger Soda from Fermentation Workshop




Equipment and materials
Equipment
· Sharp knife and chopping board
· Lemon zester or grater
· Lemon squeezer
· Rolling pin
· Large spoon
· Kettle for boiling water
· Thermometer
· Large bowl or jug
· Clean tea towel to cover bowl
· Sieve and funnel for straining
liquid into bottles
· Plastic (PET) bottle and cap.
Do not use glass bottles!

Materials
· 1 liters water
· 150 g root ginger (~130g when
peeled)
· Medium-sized lemon (preferably
unwaxed)
· 140 g sugar (brown or white)
· 4 g cream of tartar (tartaric acid)
· 4 g dried ale or bread yeast, or 8 g
fresh
· Sterilising solution suitable for
food use
· Strong plastic bag in which to
bruise ginger
· Optional: Other spices such as
chilli, nutmeg, liquorice, vanilla,
cardamom, cloves, juniper, fennel,
coriander, star anise

Method
1. Peel the ginger and cut it into slices
3–5 mm thick. Bruise the slices well
by placing them in a strong, clean
plastic bag and crushing them with
a rolling pin.
2. Place the ginger in a large bowl or
jug. Scrape the lemon zest over it,
then add the juice from the lemon.
3. Place the remaining ingredients
except for the yeast in the bowl,
then carefully pour on boiling
water. Stir.
4. Cover the bowl with a clean cloth
and leave the liquid to cool to
25–30 °C (this can take 60–90 min).
5. While the liquid is cooling, sterilise
the PET bottles using the sterilising
solution. Ensure that the bottles are
thoroughly rinsed with clean water
after sterilising.*
6. Add the yeast to the warm liquid
in the bowl and stir until it has
dispersed.
7. Cover the bowl with a clean cloth
and leave it in a warm place for 24 h.
8. Skim off the yeast, leaving the sediment
in the bowl. Strain into the
sterilised plastic bottles, leaving a
3–5 cm air gap at the top.
9. IMPORTANT! Allow the beer to
ferment at room temperature
(~21 °C) for no more than 48 h,
then place the bottles in a fridge.
Drink within six days.
* There is no need to use boiled
water to rinse the bottles after sterilisation.
The sterilising step is to
get rid of major contaminants left
in reused bottles. The tap water
used for rinsing should not introduce
contaminants, and should it
do so, they will be quickly outcompeted
by the relatively large
inoculum of yeast. The low pH of
the liquid (from the lemons) will
also prevent bacteria (although not
yeast) from growing.

Safety and other concerns
Glass bottles must NEVER be used,
as the gas produced will cause them
to explode. This drink should always
be made in plastic bottles, and it
should always be refrigerated and
consumed within six days. The short
fermentation period and refrigeration
ensure that the alcohol content of the
drink remains low.
Please remember that some religious
groups object even to the consumption
of products that contain little
or no alcohol but have been produced
by brewing. The students may,
however, be happy to take part in the
practical without drinking the resulting
ginger beer. Teachers should be
sensitive to such concerns.

Preparation and timing
It takes approximately 90 minutes
to prepare the drink, including a cooling
period of 60 minutes. The initial
fermentation takes 24 hours, followed
by up to 48 hours fermentation in bottles.
The bottles can be sterilised in
advance if desired.

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