UKC

So I've pressed some juice and now I need to pasteurise it before bottling. I'm going to do this in a saucepan. I understand I need to bring it to just below boiling point, but for how long??
Some articles say a few seconds, others 20 minutes.

Quite a difference!

In reply to Postmanpat:

Taking pasteuristion as starting at 60°C, where one minute = one Pasteuristion Unit (PU) the effect increases tenfold for appoximately every 7°C rise in temperature. For fruit juices the recommended minimum PU level is 3000, but if you bring juice close to boiling you'll get that no problem.

The Pasteurisation Units for one minute at a given temperature can be calucuated using PU = 1.393 to the power (T–60), so at 88°C you're getting more than 10,000 PU a minute.

In reply to nastyned:



Thx. Since I don't have a thermometer I got the juice to produce very very tiny bubbles and some steam (which I assume doesn't count as "boiling") and did it for 20 minutes. If I disappear from UKC you'll know that wasn't enough!!

In reply to Postmanpat:

I think the need to pasteurise fruit juice is more to do with avoiding exploding bottles.

In reply to Yanis Nayu:


Oh, it's also the risk if you pasteurise the juice whilst in the bottles!

In reply to Postmanpat:

That sounds fine, but you can get thermometers quite cheaply if you do it again.

In reply to Yanis Nayu:


Yep - it's quite hard to stop the yeasts turning it to Cider - safest if you put the juice in plastic bottles and put a small dent in before sealing so you can monitor for expansion.

Freezing the juice is often a far easier way of preserving it than pasteurising if you have freezer space.

In reply to Ron Rees Davies:

>
Ah, I was told to pasteurise before freezing.