Cider Digest #1489

eZine lover (@eZine)

Published in 

Cider Digest

 · 7 months ago

Subject: Cider Digest #1489, 9 March 2009 
From: cider-request@talisman.com 

 
Cider Digest #1489                                         9 March 2009 

                 Forum for Discussion of Cider Issues 
                      Dick Dunn, Digest Janitor 

Contents: 
  HDPE vessels (david.pickering@dpi.nsw.gov.au) 
  TA testing (Andrew Lea) 

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Subject: HDPE vessels 
From: david.pickering@dpi.nsw.gov.au 
Date: Thu, 5 Mar 2009 10:54:41 +1100 

The HDPE tanks have a history of use here in Oz for cider. FlexTank  
indicate that they have supplied about 60-80KL of tanks to Little  
Creatures Cider in Western Australia during recent years. 
If you have particular issues you want to discuss, try contacting the  
Technical Director (Anthony Flecknoe-Brown) via sales@flextank.com.au 

There are various reprints on their website discussing performance  of  
HDPE and making comparisons with oak and stainless. 
http://www.flextank.com.au/Technical.htm 
http://www.flextank.com.au/PDF_Files/2-Year-Update.pdf 

Cheers 

David Pickering 
Orange Agricultural Institute, NSW Dept of Primary Industries 
Forest Road, Orange, NSW 2800, Australia 
david.pickering@dpi.nsw.gov.au 
phone 02 6391 3800   fax 02 6391 3899   mobile 042 727 1477 

------------------------------ 

Subject: TA testing 
From: Andrew Lea <andrew@HarpHill.co.uk> 
Date: Thu, 05 Mar 2009 17:19:39 +0000 

Jason wrote: 

> I have, from Peter Mitchells excellent cider making class, the 
> following formula, assuming .2M Sodium Hydroxide Solution and 25 ml 
> of sample cider, for finding Total Acidity: 
>  
>   Malic acid(gl -1 ) = Volume(ml) of Sodium Hydroxide Solution used x 
> 0.536 
>  
> I recently purchased some Sodium Hydroxide, the strength of which is 
> defined as follows:    N/10 (0.1N) 
> How do I adjust the above formula for the different strength of 
> Sodium Hydroxide solution? 

The general equation for titration and expression as malic acid is as  
follows: 

Malic acid (g/L) = (mL of NaOH)* (normality of NaOH)* 67 / (mL of sample). 

[In the case of NaOH, which is monobasic, molarity and normality are the  
same]. 

So the equation becomes 

(mL of NaOH)* 0.1 * 67 / 25 , or 

(mL of NaOH) * 0.268. 

In other words the multiplier is half what you were given since the  
sodium hydroxide is only half as strong. 

Andrew 

Wittenham Hill Cider Pages 
www.cider.org.uk 

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End of Cider Digest #1489 
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