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MAY / JUNE 2022 27WHEN BREWERS ADD FRUIT
PUREES OR EXTRACTS JUST
BEFORE CANNING, THEY’RE FEEDING
ACTIVE YEAST A TICKING TIME BOMB.
remove the yeast from the bottom of the tank while leaving
the beer behind.
For some styles, filtration isn’t always an option. Brews
such as hefeweizens need yeast for their signature haze.
Wild beers and some sours utilise unpredictable yeast that
takes longer to ferment. Instead, pasteurisation reduces
the risk of refermentation while preserving flavour and
sugar content. At Cascade, Martin and his team pasteurise
a honey ginger lime sour ale, which incorporates raw
honey. Freshly packed cans are submerged in a hot water
bath for 20 minutes, killing off active microbes and yeast.
Not every fix demands an extra step, either. Properly
filling cans leaves a small headspace where gas can
compress and expand more easily than liquid. ‘If you have
a full liquid volume all the way to the top of your can and
that liquid expands, that’s when you’re going to get
rupturing or bowing,’ Martin says.
Brewers can test whether their methods were
successful in one of two ways. They can send a can off for
lab analysis to check for remaining bacteria or yeast. Or
for a more lo-fi approach, they can put sample cans in
warm storage and see if the tops start bowing or any beer
fizzes out after a few days. This technique is also easily
replicable for home brewers.
Although Farber and Martin emphasise that brewers
are the ones responsible for properly packaging their beer,consumers can take precautions. Refrigeration slows the
process of fermentation, so keeping your beer cold reduces
the risk of popped tops. This also prevents oxidation,
thereby preserving flavour. And, if you’re camping,
braaiing, or otherwise untethered from a fridge, your
standard ice-filled cooler will do just fine.
If you’re still concerned, have a conversation with your
local brewer. ‘Ask the staff if there are fermentable sugars
in this product,’ Martin says. Practically all beers have
residual sugars in them that contribute to taste and
mouthfeel, but rarely are those sugars at risk of
refermenting. And if you’re still not sure, there’s an even
simpler solution: Enjoy your spoils responsibly soon after
you bring them home. ‘Your best defence is to drink it,’
Martin says. Don’t mind if we do.With the proper packaging,
highly carbonated beers
don’t have to be dangerous.
Belgian-style bottles that
are made with thicker glass
and deeper punts (the
indent at the bottom of
the bottle) can withstand
greater pressure than
regular bottles and
aluminium cans. They’re
similar to champagne
bottles and have corks
with metal cages to keepthe tops from popping
off. These more-durable
containers are ideal for
fruited or especially active
beers, and any styles that
brewers want to referment
through a method called
bottle conditioning.
‘In bottle conditioning,
the carbonation comes
from a controlled
refermentation that
happens in the bottle,’
Cascade Brewing’s Kevin
Martin says. Brewers
measure a beer’s sugar
level in its finished state
and add priming sugar
at bottling to prompt
refermentation thatproduces extra bubbles.
Once the beer reaches final
gravity – the point at which
all the fermentable sugars
have been turned into
carbon dioxide and ethyl
alcohol – it’s ready for
distribution. The amount of
sugar and time it takes to
hit the sweet spot depends
on chemistry. ‘If we know
a beer has a high microbial
load, we might add a little
less sugar, anticipating that
its levels will drop further
than we expected,’ Martin
says. ‘If it has a very low
microbial load, we might
add more. There’s a little
bit of art to the science.’ALL
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