Storage and sulphites

[furneaux81]

Hi all

I've always sold my cider as draught cider. I've not used sulphites
before, but having read previous posts realise there are obvious
benefits to using them. I store some of my cider in barrels for up to
18 months.

When I put the cider into these barrels how much sulphur dioxide
should I use, and how long can I reasonably expect the sulphur dioxide
to preserve the cider? When I come to use this cider would it contain
'free sulphites' (I think this is the correct term) or would they have
become bound to the cider?

Would it also be good practice to add a little more SO2? ( I expect
the cider to be drunk within 7-10 days of being removed from the
barrel)

thanks in advance for any advice
Richard hunt

[furneaux81]

I have read the wittenham cider portals advice on sulphites, but don't
understand what ppm means, and the quantities involved if I was
sulphiting say a 100 gallon barrel of cider.

I'm intending to buy some sodium meta-bisulphate from vigo in
preparation for the coming season.

Thanks again
Richard hunt

[Andrew Lea]

The benefits of sulphite added for final storage are two-fold. It will
help to inhibit adverse bacteria eg those that cause mousiness and
acetification, or film yeasts. It will also bind to the initial aldehyde
products of cider oxidation to keep a 'fresher' flavour. Fundamentally
it is air that is the enemy of cider. Sulphite helps to mitigate some of
the effects of inevitable air exposure but it does not remove the
over-riding need to keep air away from the cider by mechanical means as
far as possible by maintaining barrels both full and tight.

The normal recommendation for bottles or stainless steel tanks is 50 ppm
added at filling, with a view to achieving around 20 - 30 ppm of free
SO2 24 hours later. That level will then only slowly drop further over
time, a bottle being a closed system. Barrels are more porous and so up
to 100 ppm SO2 could be contemplated. One caveat is that if you usually
achieve a natural and benign malo-lactic fermentation in your barrels
then the sulphite will prevent it. Don't forget many such bacteria
actually live and work in the pores of the wood while the cider matures.
So if this is part of your cider style and your customers like it,
don't use sulphite. Also, if you have used sulphite before fermentation
too, remember the EU limit for all sulphite additions in cider is a
total of 200 ppm (which Trading Standards and EHO's can easily have
measured!)

Any sulphite added to wine or cider will in part become bound (mostly to
the aforementioned aldehydes), and in part oxidised to inert sulphate.
However, only free sulphite is microbiologically or chemically active.
It is almost impossible to predict the ratio of free to bound, or the
rate of sulphite loss by oxidation, but you can invest in relatively
cheap measuring kits (eg from Vigo) which will enable you to measure the
SO2 level. You can then follow the loss in 'free SO2' over time as it
becomes bound and/or oxidised. If you were a white wine maker following
New World practices, you would aim at maintaining 25 ppm free SO2 in
your bulk stored wine at all times.

I don't think there is any practical merit in adding yet more sulphite
to a barrel once broached if it is to be used within 7 - 10 days.
Sulphite is for long-term sealed storage. And if the cider sits on
ullage longer than that, it should be transferred to a smaller sealed
container or gas blanketed anyway. Sulphite cannot protect against a
vast ingress of air - that is not its purpose. It is an adjunct to
proper storage practices, not a substitute for them.

If you are unsure about the merits of sulphite in your particular cider,
or whether 50 or 100 ppm is most appropriate for you, why not set up
some trials? There may be reasons both for and against, and only you can
decide.

Andrew Lea

--
Wittenham Hill Cider Page
http://www.cider.org.uk

[Andrew Lea]

This is the relevant website text:

"It's often easier to use a stock solution of sulphur dioxide. To make a
5% stock solution, dissolve around 10 grams of sodium or potassium
metabisulphite in 100 ml of water. (The metabisulphite salts contain
around 50 - 60% of available SO2 depending on how they've been stored).
Then 1 ml of this per litre of juice (5 ml per gallon) corresponds to
50 ppm (parts per million) of SO2."

In your case you have 100 gallons. So you need 500 ml of stock solution
to get 50 ppm sulphite. (To make the 500 ml of stock solution you need
to dissolve 50 grams of sodium metabisulphite in 500 ml of water).

Hope this helps.

Andrew

[Roy Bailey]

In message <4A789EB8...@cider.org.uk>, Andrew Lea <y...@cider.org.uk>
writes

>
>In your case you have 100 gallons. So you need 500 ml of stock solution
>to get 50 ppm sulphite. (To make the 500 ml of stock solution you need
>to dissolve 50 grams of sodium metabisulphite in 500 ml of water).
>

Perhaps it is because I am naturally bone-idle, but wouldn't it be just
as effective to dissolve the 50 grams of sodium metabisulphite directly
in some of the cider and add that to the bulk?

Roy.
--
Roy Bailey - Proprietor
The Lambourn Valley Cider Company
(Real cider from the Royal County)
<www.lambournvalleycider.co.uk>

[Andrew Lea]

Roy Bailey wrote:

> Perhaps it is because I am naturally bone-idle, but wouldn't it be just
> as effective to dissolve the 50 grams of sodium metabisulphite directly
> in some of the cider and add that to the bulk?

Don't see it's any saving in effort whether you pre-dissolve in cider or
water. But the key point is to pre-dissolve anyway, to be sure the
sulphite is well mixed in. And yes the way I put it was to make up a
stock which would get used all at one time.... so not really a stock at all!

On arcane theoretical grounds water is probably a better solvent for the
sodium metabisulphite than cider but in practice it probably don't matter!

[Rose Grant]

The great benefit of Andrews stock solution comes into play when doing
a series of pressings at the height of the season. After each pressing
I take the pH of the juice and it is then so simple just to estimate
the volume of the juice in litres (about 300 in my case) and multiply
by 1,2 or 3 in accordance with the pH table on Andrews site. The
answer is in ml. I measure the amount needed with a kitchen measuring
jug and just tip it into the juice. Job done!

Best of all it means that the horrid business of weighing out the
sulphite powder only has to be done once or twice in the season. I put
500 gms in a 5 litre demijohn and then fill it up with water from my
filter tap. It is a great idea, and I thoroughly recommend it.

Rose

[Andrew Lea]

Thank you Rose for so succinctly explaining the true purpose and use of
a stock solution!

I'll train you as a chemist if you'll train me as an engineer. Deal??

Andrew

[furneaux81]

These answers have given me a much clearer picture of how to go about
the business of sulphiting. I'll be preparing a stock solution this
autumn, and as andrew suggested will run some trials.

Many thanks for your help, I shall let you know how I get on.

Richard