Pastuerising?

[Rhu]

HI all, I have a question or two, hopefully somebody can help me out...

First thing....I've read the sticky but, I'm afraid, not all of the 986 replies to it...so if this is covered in there I apologise..

#1 If aiming for a still, completely dry cider pasteurising is not necessary unless you suspect that fermentation has not completely finished...but then why bottle heh? just leave it 'till it's ready...

#2 If aiming for a carbonated, completely dry cider, you can calculate your priming sugar using for example http://hbd.org/cgi-bin/recipator/recipator/carbonation.html and then pasteurisation still shouldn't be necessary?

#3 Bottle conditioning...if you pasteurise, is it worth storaging the cider, or have you killed off the bacteria that do all of the good things to cider? Is it the case that not all of the conditioning processes are biological and that some are purely chemical...will you alter any of the chemical processes by pasteurising the cider?

#4 Can MLF cause bottle bombs?

#5 Not strictly pasteurisation related, but one of my ciders has just started bubbling again having stopped about 2 weeks ago. Not the tiny, fizzy, champagne type bubbles that I associate with primary fermentation but larger (not big, but bigger) and slower moving, I've read that this type of bubble are associated with MLF but that can't be right after only 6 weeks can it? Can MLF start sooner at warmer temps (cider at between 25 and 27˚C)? At the same time as the cider has started bubbling again the airlock (more of a blow off tube really) has started to suck back, I would assume atmospheric pressure, but it's the only one of the 8 blow off tubes I currently have 'blowing off' that has sucked back, so could it be anything else? I can't find another explanation anywhere...especially as that cider should be producing gas not eating it? Pressing the carboy (it's plastic) moves the sucked-back liquid, so I don't think that there is a leak anywhere. Of the 8 blow off tubes, 6 are actively fermenting so I wouldn't expect anything to suck back there, but the other one is just sitting quietly not moving...

Thanks in advance.

R

 

[oljimmy]

Hi Rhu...

#1 Yes you don't need to pasteurize there, assuming that the yeast are finished. However, suppose they're not, and you're at 1.000, and you bottle. They still can, technically, take you down to .995. 5 gravity points in the bottle = high carbonation. So while you won't make bombs with very-dry cider, you can inadvertently get more carbonation than you want.

#2 Correct.

#3 I was wondering this myself, but my pasteurized batch (8 weeks ago) has definitely 'developed' in the bottle. The reason, as I understand it, is that not all of the relevant chemical reactions are from organisms. Malic Acid, in particular, just breaks down on its own over time, and this is definitely happening to my bottles.

#4 I do not know this, but I highly doubt it. The amount of C02 that would have to build up would be significant. More likely you can just take a still cider to 'slightly fizzy', which, to my mind, is more pleasant anyway.

#5 It's impossible to say for sure without an acidity kit, which you probably have no access to, but which I highly recommend picking up if you ever get the chance. That said, I do know that you can actually start MLF *during* fermentation, that is, that some people pitch MLF cultures straight into primary. The ideal temps are different: ciders ferment best below 65 and MLFs do better between 67-75, but it's theoretically do-able. So the timing of MLF shouldn't suprise you, especially at warmer temps.

 

[Rhu]

Thanks man very helpful,

Hopefully I should be getting an acidity kit today,fingers crossed...not strictly for the cider but to start getting more info out of the sea. It may occasionally find itself applied to the cider however...

I'm assuming that if I see the pH rising then it is undergoing MLF?

cheers

 

[oljimmy]

Not necessarily... PH and Titrable Acidity co-vary, but not perfectly. I believe that one can change without the other changing. Claude Joliceur's book on cidermaking has extensive data on this and a bazillion other things, I highly recommend it! Given the kind of questions you ask on here I think you wouldn't be able to put it down.

 

[Rhu]

Then I should start looking for the book...thanks..

It's all academic anyway 'cos we can't find pH testers here anyway...

Does anyone out there know for certain if pectinase can clear a cider that was initially heat pasteurised?