Residual sugar in Perry
Alexander Peckham
pears in NZ) and it is now tasting quite good and I would like to
bottle it.
The perry is quite sweet and alcoholic (7.5%). I gather that perry
contains quite a few non fermentable sugars but I want to be sure that
the product will be stable in glass. Any Ideas on how I can do this?
Many thanks,
Alex
Andrew Lea
Test it by forcing. See below.
---------------
Testing for Safety
(Pollard and Beech 1957)
- Put a test amount of bulk cider / perry
in a champagne bottle and wire down top
- Lay down in closed box at 75F / 25C for
21 days (that's the cider/ perry, not you!)
- Uncork carefully (goggles?) and assess
carbonation level
- If acceptable - proceed with bulk bottling
- If cork strains against wire and carbonation is
excessive - repeat test every two weeks
----------------
Andrew
--
Cider Workshop Website
www.ciderworkshop.com
Andrew's Website
www.cider.org.uk
Alexander Peckham
I will try that.
I have also been sent a note "can I bottle my wine unfiltered" by an
oenology company. They can test for residual glucose fructose and
tell me that will give a picture of the fermentable sugars - is this
enough?
They do have a "sterile filter" mindset and don't like in bottle
malolactic (I can understand this for a non carbonated wine wine). I
will treat with 30ppm SO2 prior to bottling and will be carbonating.
Would any in bottle malolactic produce a potentially dangerous level
of CO2 pressure?
They also talk about spoilage organisms - Pediococcus seems to worry
them - the perry has been in a tank for the last eight months is
spoilage likely to be an issue in the bottle?
Many thanks,
Alex
Andrew Lea
> Thanks Andrew,
>
> I will try that.
>
> I have also been sent a note "can I bottle my wine unfiltered" by an
> oenology company. They can test for residual glucose fructose and
> tell me that will give a picture of the fermentable sugars - is this
> enough?
Yes. Sorbitol, if present, does not ferment.
>
> They do have a "sterile filter" mindset and don't like in bottle
> malolactic (I can understand this for a non carbonated wine wine). I
> will treat with 30ppm SO2 prior to bottling and will be carbonating.
> Would any in bottle malolactic produce a potentially dangerous level
> of CO2 pressure?
No. I have posted this a couple of times before
"This is always being asked so let's work through some figures. Assume
you had a dessert apple cider at 0.7% malic acid, that is 7 g/litre. The
relative molecular masses of malic acid and carbon dioxide are 134 and
44, so the amount of CO2 that is liberated by MLF if it all goes to
completion is 7*44/134 = 2.3 grams per litre. The saturation
concentration of CO2 is around 2 g/L so if there is no other CO2 present
the overpressure is the result of just 0.3 g/L CO2 which is barely
perceptible. If the cider is still saturated with CO2 from the yeast
fermentation, then the total CO2 is 4.3 g/L. Again at 15 degrees C this
is around about 1 bar pressure."
This would be on top of anything you are adding by force carbonation.
But MLF in perry is unwise anyway because of the presence of citric acid
which can convert to unwanted acetic by ML bacteria. Your use of SO2
should stop MLF happening.
>
> They also talk about spoilage organisms - Pediococcus seems to worry
> them - the perry has been in a tank for the last eight months is
> spoilage likely to be an issue in the bottle?
The SO2 and possibly the carbonation should hopefully take care of that.
Did you tell us what the perry pH is? The lower the better (up to a point).
Claude Jolicoeur
> Would any in bottle malolactic produce a potentially dangerous level
> of CO2 pressure?
The amoung of CO2 produced depends on the quantity of malic acid that
is transformed - naturally!
Let's take a worst case scenario: imagin 8 grams per litre of malic
acid, and 100% transformation into lactic.
So 8 grams per litre transforms into 5.37 grams of lactic plus 2.63
grams of CO2 per litre. In the unlikely case of all this
transformation occurs in the bottle, you could theorically get up to
2.6 g/l of CO2 from malolactic, which would give you about 1.3 vols of
carbonation, so very slightly petillant.
Most likely, with a perry you don't have 8 g/l of malic to start with,
then you would not have 100% transformation in the bottle. So most
probably you would get something like 0.5 to 1 vols of carbonation, or
a "perlant" cider.
Claude
Alexander Peckham
the old post Andrew.