pasteurized juice in a keg

[Nat West]

I have a recovering alcoholic friend for whom I would like to better integrate into my cidermaking activities. He loves the juice I make, and I like making it for him (and for kids), but I'm a recent and nearly complete convert from champagne bottles to corny kegs. I would like to figure out how to dispense juice from kegs. Here's my thoughts.

Press fresh juice into a clean, sanitized keg, drop the keg into a pot and bring the juice up to 75 C per Andrew's instructions. Put the lid on, purge with CO2, then dispense via CO2 when I so choose. With a sub 10 psi dispensing pressure I can avoid sparkling the juice, or I can crank it up for a bubbly juice.

Does anyone have opinions on this concept? I'm slightly concerned about the rubber-plastic bumpers top and bottom on the corny kegs, as well as the rubber o-rings on the poppets and main seal and pressure relief valve, but 75 C isn't too hot in my opinion for these bits of plastic.

My biggest canning pot can easily hold one corny keg but only reach up to one-third to one-half the way up the side of the keg. If I stir it a bit, and if I'm reading temps from the top of the keg, I should be assured of 75 C throughout. It may take an incredible amount of time to reach temperature, but I'll have to try it to find out.

Thanks much,

-Nat West, Portland Oregon

[r_curtis_ha...@hotmail.com]

Hi there,

 

I don't know how long you would have to heat this for to get all of the juice up to 75 degrees C or how long you would need to hold it at that temperature before cooling it, again quite a while. I am sure the flavour would be quite different.

 

I find it is much easier to deep freeze the juice in 1 (imperial) pint milk bottles which are made from high density polythene. The juice keeps well for a year, this size thaws out pretty quickly and after thawing will last for a few days if kept in the refrigerator. If you don't have high density polythene bottles then PET fizzy drink bottles will be OK as well,

From: Nat West

Sent: Sunday, July 25, 2010 6:34 AM

To: cider-w...@googlegroups.com

Subject: [Cider Workshop] pasteurized juice in a keg

--
You received this message because you are subscribed to the Google Groups "Cider Workshop" group.
To post to this group, send email to cider-w...@googlegroups.com.
To unsubscribe from this group, send email to cider-worksho...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/cider-workshop?hl=en.

[Melanie Wilson]

 I think if I needed to pasteurize a bulk quality, in one container,  I'd look to some kid of immersion heater to do the job, last year I was looking a plant or making a pasteurizer that heats a small amount as you bottle it (or put it into a kegs I guess although the temp drop in larger amount might risk new contamination.

 

Mel

 

 

 

[Andrew Lea]

On 25/07/2010 06:34, Nat West wrote:
>
> . It may take an incredible amount of time to
> reach temperature, but I'll have to try it to find out.

Yes this could be the weakest link. Commercially nobody would attempt to
batch pasteurise such a large bulk - it would be flash treated in a flow
through heat exchanger and hot filled. I suggest adding at least double
the normal amount of ascorbic acid i.e. 1000 ppm instead of 500 to try
to mitigate oxidation. Otherwise you might end up with something very
brown and cooked.

Also be careful of sterility / contamination issues in the top part of
the vessel and its lid which are not being contacted by hot (sterile)
juice. Can you fit the lid loosely while you heat?

Andrew

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

[Nat West]

Melanie and Andrew mentioned the length of time to bring up to temperature and Mel recommended an immersion heater. I might give this a try, two 1500 watt heatsticks (as they're known in the US brewing world) would probably work well. And after bringing up to temperature, I would have to seal and flip the keg so the hot juice gets onto the lid.

What about SO2 addition? Or would that not effectively kill yeast for a long-term storage? How about lots of pressure, like 30psi to inhibit yeast activity?

Maybe there's no great way to make this happen on my small scale since I would like to store kegs for a few months.

-Nat West, Portland Oregon

[Andrew Lea]

On 05/08/2010 20:07, Nat West wrote:
> Melanie and Andrew mentioned the length of time to bring up to
> temperature and Mel recommended an immersion heater. I might give this a
> try, two 1500 watt heatsticks (as they're known in the US brewing world)
> would probably work well.

Not advisable if you plan to put the heatsticks straight into the juice.
Without adequate stirring you will get too much local heating and the
juice will end up very 'cooked'. I realise this may be your only option
but be aware!

>
> What about SO2 addition? Or would that not effectively kill yeast for a
> long-term storage? How about lots of pressure, like 30psi to inhibit
> yeast activity?

You would need a lot of SO2 to do the job, at which point you will be
able to taste it. Benzoate at high levels (I think up to 1000 ppm is
legal in the US) is another possibility but also suffers from taste
issues. Also some spoilage yeasts like Z. bailii are totally SO2 and
benzoate resistant so there's no guarantee. 30 psi is only 2 atm of CO2
and not enough to inhibit much. You would need at least twice that
pressure and low temp (32F) I think. Also lactics and eventually some
yeast will grow even in juice under high CO2 (this used to be done
commercially on bulk juice in the 1950's (the Boehi system) but was
discontinued for this reason).

>
> Maybe there's no great way to make this happen on my small scale since I
> would like to store kegs for a few months.

I think you are battling the laws of nature here. Heat is probably the
least worst solution but on the scale you plan I think it will be
difficult to maintain quality. If you want your juice brown and tasting
of baked apple then that's OK! If it were easy people would already be
doing it!! Bottles of 750 ml are easily do-able at home while
maintaining quality but the difficulty of handling bigger volumes
increases exponentially.

Good luck with whatever you choose!

[Justin Bighouse]

What about Potassium Metabisulfate to kill yeast, as opposed to pasteurization