Storage conditions for cider

[Alan Henry]

Hello all

New member here and first time post. This year I am transitioning
from producing cider for own consumption to producing as a business.
Could someone please provide me a maximum recommended temperature for
storage of the following, both made with min 90% apple juice,
fermented with commercially available yeasts.
(a) pasteurised bottled and capped cider;
(b) unpasteurised bottled and capped cider;

many thanks

Alan

[JezH]

Hi Alan and welcome along!

Where abouts are you? In the UK, ambient temperature would be fine for
both of these I would suggest - although clearly cooler is more
desirable, especially if any of your cider is carbonated or bottle
conditioned.

I recall reading somewhere - probably in Ciderland, although James
Crowden was almost certainly quoting from somewhere else, that lively
cider was best kept in a cool stream or well. Those better read will
almost certainly be cursing me for my poor paraphrasing, but I have
always been influenced by the idea of keeping cider cool.

I don't think I would treat pesteurised or non pasteurised any
differently.

Jez

[Andrew Lea]

You will not get an exact answer to your questions because this is not a
pass/fail kind of situation. Instead, you need to consider the general
principles behind what you are asking and then think it through for
yourself.

Pasteurised sealed cider is microbiologically stable for all practical
purposes because of the heating step. So from the point of view of yeast
or bacterial activity, temperature does not matter. The organisms are
dead. However, the cider is not chemically stable and it can still
change if the temperature is high for a long time. The old chemists rule
of thumb is that a chemical reaction goes twice as fast for every 10C
rise in temperature, but is linearly proportional to the time. Therefore
if you keep it at 30C it will deteriorate twice as quickly as when kept
at 20C, four times quicker than at 10C. In the food industry overall,
4C is generally regarded as a place where chemical changes in
pasteurised products are pretty slow. Most people do not have the
facilities for such refrigerated storage so the coolest you can
realistically manage is the best. If the temperature peaks for a few
days in summer (hollow laugh!) at 35 or 40C well so be it. In terms of
cumulative time*temperature the effect is likely to be slight and can be
offset against those long cold days of winter!

The main effect you will notice is a slightly enhanced cooked flavour
resulting from the Maillard (caramelisation) reaction which proceeds
slowly even at room temperature. This can be largely mitigated if you
include 50 ppm of SO2 at bottling, because the SO2 scavenges the initial
Maillard products and inhibits their further transformation into cooked
flavours. I have had sweetened pasteurised (and sulphited) cider stored
in an unprotected garage for 4 years now and although it is noticeably
different (to me) than it was 4 years ago, my friends still find it
acceptable and are happy to drink it (as indeed am I). So even if the
flavour changes, it doesn't necessarily diminish its consumer acceptability.

Your second question about unpasteurised cider is much more complex and
uncertain. For one thing you have not said if the cider is dry, sweet,
keeved, bottle conditioned or what. But in all cases the cider is still
microbiologically active and this effect will be paramount. Obviously a
sugar sweetened bottled unpasteurised cider will have a life of only a
few days until it referments and explodes unless special precautions
have been taken such as keeving and/or unless you have chosen the sugar
level to be within the pressure rating of the bottle. That is the
primary issue.

But even in a dry unpasteurised cider, microbiological changes can take
place. The most likely of these is the bacterial malo-lactic change,
which can induce some sparkle, change the flavour profile and drop the
acidity by half. Unlike chemical reactions, the response of microbes to
temperature is much more acute and not at all linear. For instance, MLF
bacteria will not normally be active at all at temperatures below 17C or
so, but once even a degree or so above that, they may become very active
indeed. They will also be inhibited by SO2 so if you don't want MLF in
bottle, use SO2.

If the cider is formally bottle conditioned and contained live yeast and
is unsulphited, all sorts of flavour changes may occur over time,
engendered by Saccaharomyces, Brettanomyces and Lactobacilli to name but
three. If you want to minimise any microbial change, then cool storage
as close to 4C as possible is probably best. But if you let the cider
experience ambient time and temperature conditions, it may not suffer
and it may even improve. A couple of weeks ago I opened a garage-stored
keeved cider which was 8 years old. It was absolutely fine and had an
aged complexity of flavour which I found very interesting. A sample
about 4 years old, which I had dismissed as being too sulphidic at the
time, had matured quite wonderfully, lost the sulphur and gained some
complex estery notes and was highly enjoyable.

None of this answers your question but maybe gives you a way of thinking
about what the answers might be in your particular case.

Andrew

--
Wittenham Hill Cider Portal
www.cider.org.uk

[Alan Henry]

Thank you Jez and especially to Andrew for that definitive answer to
the question, which I have already copied and filed. The "fishing rod"
as you say is much more valuable than "the fish" itself!!

The cider is dry and I am thinking of bottle conditioning a real cider
for purists and was trying to understand the risk, and also to
estimate the investment for storage of pasteurised cider. I virtually
always bottle condition my own and it usually comes out vel, although
the result is sometimes inconsistent from one bottle to the next. I
put this down to non-homogeneity of my cider (fermented in 50 ltr
demijohns); slight variability in the sugar amount, and in the ambient
temperature.

Incidentally the temperature will reach 34oC today where I am!

Good day to all

Alan