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Cider Digest #1160
Subject: Cider Digest #1160, 31 August 2004
From: cider-request@talisman.com
Cider Digest #1160 31 August 2004
Forum for Discussion of Cider Issues
Dick Dunn, Digest Janitor
Contents:
Last Call for PME Sample ("Gary Awdey")
Iodine test ("Trevor Fitzjohn")
Iodine starch test (Jack O Feil)
Re: Cider Digest #1159, 30 August 2004 ("Gary Awdey")
Apples ripening (Tim Bray)
Nitrogen blanketing? (Andrew Lea)
Ripeness testing (Andrew Lea)
Re: Starch-Iodine tests ("Ian A. Merwin")
Carbonating "small" batches of cider ("J. K. Davis")
Re: iodine and maturity (tblists)
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----------------------------------------------------------------------
Subject: Last Call for PME Sample
From: "Gary Awdey" <gawdey@att.net>
Date: Mon, 30 Aug 2004 20:45:59 -0400
For any who may be thinking of a trial keeve this year using pectin methyl
esterase (PME) I'll be taking requests through the end of this week (Sat.,
Sept. 4) and packaging them up this weekend. (If you somehow missed the
earlier discussion you can find most of it in Cider Digest postings #1151 -
1155.) This will be coming out of a larger free sample provided by one of
two domestic suppliers (or both if you specifically request it). I'm
planning to include a data sheet that gives recommended dosage for the PME
and calcium chloride (you can do your own conversions if you prefer to use
calcium carbonate), as well as supplier product data sheets and Material
Safety Data Sheets (MSDS's). Once packaged I'll be sending them out on the
first reasonably cool day (to minimize the likelihood of loss of activity
due to excessive temperature). These are free, I only ask that you consider
sharing anything noteworthy in your results (good or bad) in future postings
so others can benefit from your experience. Be sure to give a rough idea of
how much cider you may be making with a PME keeve. If in doubt estimate on
the high side so you won't have later regrets when your plans become more
ambitious (Scott Smith has offered to share his supply if there is
sufficient interest to use up all the surplus that I have on hand). Send an
email message to me at gawdey@att.net. Be sure also to include your mailing
address (I won't share that information with anyone else except possibly
Scott).
Gary
------------------------------
Subject: Iodine test
From: "Trevor Fitzjohn" <tfitzjohn@pacificradiology.co.nz>
Date: Tue, 31 Aug 2004 13:09:45 +1200
Further to the discussion on ripeness of apples and iodine test. I have
found reference to this test in my notes to the now defunction online
cider course from Penshore college. I believe this was the course Peter
was leading before the course closure, but I havn't any deytails re
strength of iodine to use, how to use it etc. Andrew can you supply the
nitty gritty please for all of us budding chemists? Regards Trevor
------------------------------
Subject: Iodine starch test
From: Jack O Feil <feilorchards@juno.com>
Date: Mon, 30 Aug 2004 18:47:31 -0700
Commercially,Spraying an apple cut across the middle, with an
Iodine solution is one of the primary indicators of when to pick, the
other is punching with a pressure tester. I suppose you want as much
starch converted to sugar consistent with the ability to grind the apple
to press to out the juice. When all of the starch is converted (no black
where sprayed with the Iodine solution) you are running the risk of a
mealy apple that is difficult to juice. When I pick for my roadside stand
I pick for flavor(not long term storage) and for most varieties that is
when there is some unconverted starch near the outside and a few
blotches toward the inside, these areas show up as black or grey when
sprayed with the iodine indicator solution. This test solution is readily
available in commercial orchard areas(I live in apple producing area of
North Central Washington) but I'm sure you could dilute tincture of
iodine with water and that would last a long time. I use an expired
window wash spray bottle to spray the cut apple.
As for pressure testing, do it the age old way, press the apple
with end of your thumb and if it gives with a snap that apple is mature
and ready to pick. If your thumb dents the apple with only modest
pressure and no snap the apple is over ripe, on the other hand if it
takes a lot of pressure to dent the apple and there is only give but no
snap then that apple is immature and needs to hang a while longer.
Jack Feil
------------------------------
Subject: Re: Cider Digest #1159, 30 August 2004
From: "Gary Awdey" <gawdey@att.net>
Date: Mon, 30 Aug 2004 22:06:55 -0400
Trevor Fitzjohn wrote:
>Further to the discussion of CO2 and argon for blanketing cider, are
>there any other gases that can also be used. <snip> ...I can get cheap
>bottled nitrogen (N2) which I
>have used with success so far. Am I being lucky? Or are there others
>using it? Are there any other inert gasses to consider?
I doubt that you're just being lucky though I don't have any references at
hand that discuss this specifically for cider. There seems to be more
information pertaining to commercial production of wine. According to the
HANDBOOK OF ENOLOGY, Vol. 1 (P. Ribereau-Gayon et al, 2000, translated by
Jeffrey M. Branco, Jr., ISBN 0471 97362 9) nitrogen is one of three gases
authorized for storage of wine (as you may have expected from the discussion
to date the other two are argon and carbon dioxide). Argon is rarely used
because of cost and very low solubity. Carbon dioxide is very soluble in
wine and is sometimes mixed with nitrogen (eg 85% nitrogen and 15% carbon
dioxide) to prevent the degassing of certain wines that must maintain a
moderate carbon dioxide concentration. For wine nitrogen is the most
commonly used gas and (still citing Ribereau-Gayon) the small amount of
oxygen that occurs in "R" quality nitrogen has no impact on wine. I'm not
sure about general preferences in New Zealand but in North America they seem
to call for more carbon dioxide in cider than in wine. Assuming you'd want
at least a small amount of carbon dioxide, unless the cider is completely
dry or pasturized I'd expect some carbon dioxide to be generated during
storage and wouldn't worry much about displacing it with unmixed nitrogen.
Gary
------------------------------
Subject: Apples ripening
From: Tim Bray <tbray@mcn.org>
Date: Mon, 30 Aug 2004 21:12:31 -0700
Dick asked about ripeness testing, and then suggested a simple iodine test
(reacts with starch) - can't believe that never occurred to me!! I suspect
it doesn't show up in many books because most authors really don't think
about this problem; you are just supposed to know when your apples are ripe.
I have the same problem as Dick - lots of varieties, none of which are
grown around here by anyone else, and an odd climate. I've been testing
mainly by tasting for starch. But Dick correctly notes that this can be
difficult with cider apples; I made this same point to my wife just a
couple of days ago, while trying to decide when to pick some Kingston
Blacks. These are so tannic and so strongly-flavored that it's hard to
detect the starch as they get close to ripeness.
So, I'm off to the chemist, as Andrew might say, for some iodine!
Slainte,
Tim
p.s. Just picked Hewes Virginia Crab - first crop from the trees planted
three years ago. Looked like bunches of cherries! Smell good,
too. Planning to press in the next couple of weeks.
------------------------------
Subject: Nitrogen blanketing?
From: Andrew Lea <andrew_lea@compuserve.com>
Date: Tue, 31 Aug 2004 08:18:22 +0100
Trevor wrote:
>
> Further to the discussion of CO2 and argon for blanketing cider, are
> there any other gases that can also be used. Argon is very expensive in
> New Zealand. As a doctor I can get cheap bottled nitrogen (N2) which I
> have used with success so far. Am I being lucky? Or are there others
> using it? Are there any other inert gasses to consider?
Nitrogen *is* used in the wine and cider industries for blanketing.
There are natty little membrane systems on the market which selectively
pluck the nitrogen out of the air (78%) on demand, and pressurise it all
ready to pump to wherever you want - you don't have to order a cylinder
or a dewar flask of liquid nitrogen - it's always ready and the raw
material is still free (they don't tax air - yet!). The advantage of
CO2 and argon is that they're denser than nitrogen (which has much the
same density as air and so tends to drift away) so they'll stay where
they're put for longer and will tend to fall downwards into the bottom
of a vessel. A further (possible advantage) of CO2 is that it actually
disssolves in the drink to a very significant extent and most ciders and
wines are actually improved by being at saturation with CO2 (even if
nominally 'still'). Other inert gases? Krypton and xenon sound rather
fun! Radon might make a cider quite interesting! Sadly, I think the
only practicable ones are the ones we already discussed!
Andrew Lea
- --
Wittenham Hill Cider Page
http://www.cider.org.uk
------------------------------
Subject: Ripeness testing
From: Andrew Lea <andrew_lea@compuserve.com>
Date: Tue, 31 Aug 2004 08:45:58 +0100
Dick wrote:
> Last fall in a cider class, Peter Mitchell mentioned just using an iodine
> test: put a bit of tincture of iodine on a cut piece of fruit. Where it
> turns gray-black, there is unconverted starch indicating ripening isn't
> complete. If it stays yellow-brown, it's not reacting to starch. I played
> around with this and noticed that in a nearly-ripe fruit you'll see the
> blackening out toward the skin when the inside doesn't show any (i.e.,
> ripening from the core toward the skin). I swapped notes with Andrew
> Lea off-list; he says that the test is commonly used by commercial growers,
> and that the differential ripening I saw is known and understood. That
> can even give you an indication, with an unripe apple, of how close it
> is.
>
The interesting part about that (see e.g.
http://www.gov.on.ca/OMAFRA/english/crops/facts/00-025.htm ) is that the
commercial
growers are deliberately pitching to harvest under-ripe, to put the
fruit into gas store. So they don't wait for all the iodine colour to
disappear - whereas we cidermakers do.
> BUT...I hunted around a bit and couldn't find the iodine test described
> in ANY of my cidermaking books.
>
> Well, why not?
It is curious, somehow. Perhaps your typical craft cidermaker just
'knows in his bones' when the fruit is ripe! I know that the large
cidermakers monitor the starch to sugar conversion like hawks (but not
with iodine, which isn't sensitive enough for them). More fermentable
sugar in the fruit means less they have to buy in to get the alcohol
level they need!
Andrew
------------------------------
Subject: Re: Starch-Iodine tests
From: "Ian A. Merwin" <im13@cornell.edu>
Date: Tue, 31 Aug 2004 08:47:33 -0400
In regard to the recent question about using starch iodine tests for
apple maturity, there is a bulletin available from Cornell University
with detailed information about maturation and ripening of apples,
preparing the potassium iodine formulation, with illustrations of
fruit starch patterns that are useful for interpreting the resulting
patterns to derive a numerical "starch index" of harvest maturity.
The publication is Information Bulletin No. 221, "Predicting harvest
date windows for apples," by G.D. Blandpied and K.J. Silsby. It can
be ordered from the resource center online for $5.75 at
<www.cce.cornell.edu/store/customer/home.php?cat=439 >.
Interpreting the starch patterns is problematic, because each apple
variety reaches "optimal" harvest maturity at a different starch
index (usually between 3.5 and 6.0), and the patterns vary from year
to year even for the same variety. A more low-tech approach is to
walk through your orchard daily as harvest time approaches, tasting
each variety to check for development of its characteristic flavor
and aromatic traits, slicing fruit to look at seed browning, watching
for the onset of drop (many of the bittersweets will drop most of
their fruit as it ripens). The underlying skin groundcolor transition
from greenish to cream white or yellow is a reliable indicator of
ripening, that is independent of red or orange blush (which is an
effect of direct sunlight on the fruit that often occurs well in
advance of ripening).
If you can store your cider apples in a cooler around 3 to 5 degrees
C for a month or so before pressing them, they will mellow (ethylene
from the most ripe fruit induces ripening in the less mature fruit)
and most of the remaining starch will hydrolyse to sugar, improving
your cider yields.
- --
(((((((((((((((((((!))))))))))))))))))))
Ian A. Merwin PhD
Assoc. Prof. of Horticulture & International Agriculture
118 Plant Science, Cornell University
Ithaca, NY, USA, 14853
im13@cornell.edu
------------------------------
Subject: Carbonating "small" batches of cider
From: "J. K. Davis" <andiroba@hotmail.com>
Date: Tue, 31 Aug 2004 15:44:40 -0400
Gentle Cider Makers:
A question regarding the best way to carbonate smaller batches of cider,
e.g, 50 gallons or less.
I've search the Internet and cider references, and haven't been able to
locate any suggestions on equipments or methodology of carbonating cider
beyond the adding sugar at bottling. I am loath to do that because of the
lack of control. May I ask your opinions on a method to do this?
Jan Davis
Weasel Hill Farm
Amissville, Virginia
------------------------------
Subject: Re: iodine and maturity
From: tblists <tblists@pshift.com>
Date: Tue, 31 Aug 2004 20:23:20 -0400
I use iodine for testing apples all the time. Since you're generally
looking for full ripeness with cider fruit, I'd test the fruit weekly until
you see the core and some flesh turn white, then twice weekly after
that. Once the entire surface of the (horizontally) cut fruit is all
white, then there is no starch left. Note however, that some varieties
don't respond well to this test. Fuji is my only example...I've never used
it on cider fruit.
UMASS offers an explanation here:
http://www.umass.edu/fruitadvisor/clements/articles/sitest.htm
And a place to get iodine and charts, if needed:
http://www.cascadeanalytical.com/agriculture_svcs/agricult.htm#maturity
Note that the charts are used because commercially packed and stored fruit
should be pocked before they are dead-ripe. I assume cider fruit would
want to be as ripe as possible.
Also, note that the iodine solution is considered toxic, and handle
appropriately. I don't know if drugstore iodine tincture is the same as
the saturated potassium iodine solution I use...I make it from the recipe
mentioned at the end of the UMASS article.
TB
At 06:34 PM 8/30/2004 -0600, you wrote:
>Last fall in a cider class, Peter Mitchell mentioned just using an iodine
>test: put a bit of tincture of iodine on a cut piece of fruit. Where it
>turns gray-black, there is unconverted starch indicating ripening isn't
>complete. If it stays yellow-brown, it's not reacting to starch. I played
>around with this and noticed that in a nearly-ripe fruit you'll see the
>blackening out toward the skin when the inside doesn't show any (i.e.,
>ripening from the core toward the skin). I swapped notes with Andrew
>Lea off-list; he says that the test is commonly used by commercial growers,
>and that the differential ripening I saw is known and understood. That
>can even give you an indication, with an unripe apple, of how close it
>is....
> It's nearly objective--once
>you see how it looks on one ripe apple and one unripe apple, there's
>little judgment required to interpret the test. A one-ounce bottle of
>iodine, at the exorbitant price of several dollars from a drugstore,
>will probably suffice for the rest of my life. There's no grinding
>or pressing, and nothing to clean but a knife.
================
Terence Bradshaw
1189 Wheeler Road
Calais, VT 05648
tblists@pshift.com
(802)229-2004
1450 feet, zone 4A/B?
The views represented are mine and mine only........
------------------------------
End of Cider Digest #1160
*************************
