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Cider Digest #1152
Subject: Cider Digest #1152, 29 July 2004
From: cider-request@talisman.com
Cider Digest #1152 29 July 2004
Forum for Discussion of Cider Issues
Dick Dunn, Digest Janitor
Contents:
Acid adjustment in single variety cider (Donald Davenport)
RE: Pectic Enzymes ("McGonegal, Charles")
Apple Tree Roots (directory)
Pectinase vs. keeving ("Dyer, Jonathan A.")
Pectic enzymes (Andrew Lea)
Re: Cider Digest #1151, 26 July 2004 ("Joe Hecksel")
Re: Cider Digest #1151, 26 July 2004 ("Gary Awdey")
Re: Results of Preliminary Trial With Pectin Methyl Esterase ("Gary Awdey")
Re: Problems with 2004 PME keeve ("Gary Awdey")
Re: Availability of PME Sample ("Gary Awdey")
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Subject: Acid adjustment in single variety cider
From: Donald Davenport <djdavenport@earthlink.net>
Date: Mon, 26 Jul 2004 21:13:10 -0600
I'm a new subscriber with a newly planted orchard. Forgive what might
seem a simple question.
I see a lot of single variety ciders being offered. Mostly Kingston
Black, Yarlington Mills and now I see some Dabinett, which I had
originally planted as blending stock.
Making a single variety cider out of Kingston Black makes sense to me
because the components are all there. Sufficient tannin and sugar.
Acid +/- .6% The perfect combination.
But, on the other hand, Dabinett seems to be extremely low in acid.
(.18%)
Are people adding malic acid to their Dabinett must to lower the pH?
And if you have to add sharpness to balance the cider (or prevent cider
sickness) wouldn't just blending it make more sense? Or are there
other characteristics in Dabinett that justify it being bottled as a
single variety even if you have to chemically change some of its basic
components.
Again, sorry if I'm missing the big picture here.
Thanks,
Donald Davenport
------------------------------
Subject: RE: Pectic Enzymes
From: "McGonegal, Charles" <Charles.McGonegal@uop.com>
Date: Tue, 27 Jul 2004 11:44:39 -0500
Good day Scott,
Hopefully your questions will raise some good discussion. I know a few
others in this forum have some more practice / research than I - but I will
toss in my 2 bits anyway.
I use a pectolytic enzyme in my cider (and especially dessert pear perry)
fermentations. I always get a nice brown cap right at the start of
fermentation, though I do not make use of it in the keeving sense. I'm
aiming for a champagne method cider, so I don't mind the complete
fermentation. I let the brown cap fall without racking. I _do_ think that
it is important in helping clear the cider - so it ends up brilliant, with
no haze.
I do not add calcium to the must. We do use foliar calcium sprays on the
orchard, so I suspect I've got a certain amount even without direct
addition.
It's my understanding that general pectolytic enzymes fragment pectin
polymers, while PME activity is more targeted to de-branching. I wonder if
part of the reason PME seems to yield a much better keeve is that the long,
slender debranched molecules coagulate better than short fragments. (Sort of
the same way cis- fatty acids stack together in arteries more effectively
than trans-).
Now here's a consideration for US commercial cider makers - calcium chloride
isn't on the ATF's approved materials list. I suppose that it's probably a
moot point, given that keeved ciders are aiming for low alcohol, and would
fall into FDA territory. But it's something to be aware of, I think.
One last note on PME. Artisan distillers avoid it to the point that they
cook certain fruit 'mashes' _before_ fermentation, just to kill off any
natural PME activity. And studies with commercial pectolytic enzymes show
enough PME activity to raise methanol levels in the final eau de vie by
about 10 fold. Thankfully methanol isn't a concern for cider makers.
Charles
AEppelTreow Winery
------------------------------
Subject: Apple Tree Roots
From: directory <buchandlung@yahoo.com>
Date: Tue, 27 Jul 2004 11:03:09 -0700 (PDT)
Hello Dick Dunn,
It is always such a pleasure to read your Cider Digest.
Although I have yet to make any cider we do have some apple trees which is
the focus of this email. I am wondering if you have a suggestion on how to
trim some roots which have become a problem with a brick wall. A root (3/4"
diameter) has penetrated a 12" thick brick wall approximately 4 feet from the
base of the tree and is causing damage to the wall. The apparent solution
is to cut the root off at the wall but I am concerned about the effect on
the 40 year old tree. Is there something I should do to the root that will
help alleviate any problem which could arise from cutting the root??
Much obliged,
Karl Buck
------------------------------
Subject: Pectinase vs. keeving
From: "Dyer, Jonathan A." <dyerja@health.missouri.edu>
Date: Tue, 27 Jul 2004 13:07:57 -0500
In response to Scott's comments on pectinase vs.. keeving I would think
that keeving would do a better job removing nitrogen from the
unfermented cider as the chapeau brun truly acts as a trap for many
nutrients. This is much different than pectinase which just digests
down the pectin to make it harder to set up a haze. In the case of
pectinase it would seem the majority of nutrients and other compounds
typically removed by keeving would still be free in the cider to be
utilized for fermentation. Keeving, while certainly more time consuming
and less predictable, would still yield a more elegant result.
Jon Dyer
------------------------------
Subject: Pectic enzymes
From: Andrew Lea <andrew_lea@compuserve.com>
Date: Tue, 27 Jul 2004 22:16:28 +0100
Scott Smith wrote:
>
> I'm planning my fall cider at this point, and the latest issue I have
> been contemplating is pectic enzymes. I want to make a French-style
> cider, and so I want to remove the pectin nutrients by keeving.
Hold on there! Pectin is not a nutrient! Keeving removes *nitrogenous*
nutrients by entrapment in a pectin gel. The pectin is just a carrier.
> The keeving process removes methyl esters from pectin chains and these
> sites then bond with calcium ions to form a gel which rises and forms
> the chapeu brun. But, in the wine and juice world today, the standard
> way to remove pectin is to use pectinase, a combination of enzymes that
> breaks apart the long pectin chains, and precipitates the fragments
> (right?).
Yes but wrong! (sorry). The juice clarifies, but the degraded
galacturonic acid from 'pectinase' remains in solution in the juice.
>The downside of these enzymes seems to be that some of the
> by-products are things that do not precipitate, and can contribute to
> off flavors.
Not a serious problem in practice unless very unusual enzymes are used.
With most commercial PG/PME cocktails there are no flavour problems.
>
> So, is the main reason why the French use the keeving method instead of
> a standard pectic enzyme because the lack of these unfortunate
> by-products, or are there other reasons such as more complete pectin
> extraction, or the fact that keeving keeps around (or, gets rid of)
> some other compounds?
They do it primarily to remove nitrogenous nutrients. And no
commercial pectic enzymes were available until the 1930's - keeving had
been done for centuries before that!
> In Andrew's Science of Cidermaking I read how keeving reduces the
> Nitrogen content; is there something else different
> to keeving that is somehow getting our more Nitrogen than a standard
> pectic enzyme treatment?
>
Yes. Keeving is all about nitrogen removal! Conventional pectic enzymes
do not remove any nitrogenous nutrients. The traditional French/ English
method is not actually about removing pectin at all - that's just
incidental. It's about removing positively charged amino acids and
thiamin (which bind to the pectate anion generated by PME) and thereby
slowing down the fermentation after removal of the 'chapeau brun'. For
centuries this was done without added enzymes just using the natural PME
(pectin methyl esterase) in the apples. Only in the last 10 years has a
commercial enzyme to do this specific job become available.
> The key question I have in my mind is whether I should use a standard
> pectic enzyme to remove the pectin, or attempt a keeve this fall. I
> have a bit of the magic keeving PME enzyme to experiment with but I
> still wonder if I am not better off with a normal pectinase enzyme
> since keeving often can fail, even with the added enzyme.
>
Please be clear that a regular pectic enzyme will not remove any
nitrogenous nutrients - all it will do is to clarify the juice! Keeving
may or may not be successful but regular pectic enzymes will *never*
reduce your nutrient levels! If it were that easy we'd all have been
doing it for ever!!
Andrew Lea
- --
Wittenham Hill Cider Page
http://www.cider.org.uk
------------------------------
Subject: Re: Cider Digest #1151, 26 July 2004
From: "Joe Hecksel" <jhecksel@voyager.net>
Date: Tue, 27 Jul 2004 17:41:29 -0400
> The key question I have in my mind is whether I should use a standard
> pectic enzyme to remove the pectin, or attempt a keeve this fall. I
> have a bit of the magic keeving PME enzyme to experiment with but I
> still wonder if I am not better off with a normal pectinase enzyme
> since keeving often can fail, even with the added enzyme.
>
You might try adding some whole crabapples to your fermentation if you
are in an experimental frame of mind. I added some M.X robusta crabs
(2/gallon)
http://www.ars-grin.gov/cgi-bin/npgs/html/acchtml.pl?1006721
and they had enough pectin digesting enzyme to make the finished
product crystal clear.
Good Luck!
- --
Joe Hecksel
Personal Webpage http://my.voyager.net/~jhecksel
------------------------------
Subject: Re: Cider Digest #1151, 26 July 2004
From: "Gary Awdey" <gawdey@att.net>
Date: Thu, 29 Jul 2004 06:30:27 -0400
In CD#1151 Scott Smith wrote:
>So, is the main reason why the French use the keeving method instead of
>a standard pectic enzyme because the lack of these unfortunate
>by-products, or are there other reasons such as more complete pectin
>extraction, or the fact that keeving keeps around (or, gets rid of)
>some other compounds?
Right, but the information I've seen online suggests that the pectinase is
generally also being used in grape must extraction to improve yield and/or
provide certain (hopefully) desirable qualities it might not have otherwise.
While the same could be true for cider, use of extractive enzymes in
improvement of yield can be controversial (in both sweet and hard cider) and
you won't find many commercial cidermakers who will 'fess up to using it
prior to pressing. Use of enzymes as an aid in extraction would probably
cause many to assume the cidermaker is more interested in cutting costs than
in producing cider of desirable quality (regardless of how various aspects
of quality are actually enhanced or compromised). It's possible a strong
argument could be made in favor of use of enzymes in extraction in a
case-by-case basis, provided it is supported by objective taste tests.
However I'd be highly skeptical of any blanket assertions about desirability
or undesirability of the use of extractive enzymes an aid in extraction in
cidermaking without a large body of experimental evidence to support it.
Perhaps someone like Andrew can give a more detailed picture of the benefits
of PME vs. pectinase blends aside from the different types of haze you might
encounter. I don't know of anyone personally who uses pectinase to improve
yield in hard cider but do know of some who use it after pressing in
keeving/clarification. At least one who does is not interested in giving
"pure" pectin methyl esterase (PME) a try because he's already found
something that works. I have no idea yet if less fining and/or filtration
would be required to achieve the same results with PME vs. pectinase blends,
or the extent to which by-products can be detected in tasting, but I've
wondered about it. Maybe a side-by-side trial of PME vs. some pectinase
blends using juice from the same pressing would give a better idea of the
practical differences. However, my understanding of PME is that this is an
enzyme that occurs naturally in apples, though typically at a low level of
activity. The addition of PME after pressing is simply a way of improving
the reliability of the keeve. Interestingly, the idea of using PME derived
from Aspergillus niger seems to have arisen from someone noticing that there
was small volume of juice that clarified spontaneously in the immediate
vicinity of some mold in the juice. In nature, certain microorganisms and
fruit would have different biological reasons for producing enzymes capable
of breaking down pectin but in the case of PME in cider the result is
identical.
Gary
------------------------------
Subject: Re: Results of Preliminary Trial With Pectin Methyl Esterase
From: "Gary Awdey" <gawdey@att.net>
Date: Thu, 29 Jul 2004 06:55:41 -0400
Scott's message was also a good lead-in to a follow-up on some related
stuff.
I ran a preliminary trial of PME last winter on some Golden Russet cider
(with 50 ppm potassium metabisulfite added shortly after pressing). Mostly
it was just to give a practical idea of how to design future trials. The
main variable was the amount of calcium chloride used as a precipitating
agent. Some interesting results emerged.
The amount of precipitating agent (eg calcium chloride) required is expected
to vary with the juice because pectin content is a variable as well.
Unfortunately there is not a convenient way to measure pectin content so you
really need to make your best guess. Andrew speculated a range of 0.1 to
0.5% pectin in some offline correspondence last year, based on various
sources in literature, with 0.3% as a reasonable assumption in the absence
of an actual measurement. Fortunately my first trial results suggest that
there is adequate room for SOME degree of variation in CaCl2. The upper
range of recommended calcium addition is about 400 ppm, above which you run
the risk of giving the cider a salty taste (though if more is consumed in
crosslinking the pectin chains then adding slightly more is less likely to
be a problem). Last winter using the same pressing of juice for several
trial batches I found I could achieve visually identical results using a
CaCl2 addition of 12 g and 17.4 g to 5 gallons of juice. Above an apparent
threshold somewhere between 8 and 12 grams or CaCl2 per 5 gallons (for this
particular juice) the gelled pectin produced a nice "brain in a jar" pectin
gel effect fairly quickly. Going too far below this CaCl2 concentration
resulted in partial precipitation of the pectin into very small, visible
agglomerations (I'll call them specks) that tended to keep their distance
from each other (perhaps due to a net ionic charge at the outer surface of
each). They didn't seem to want to rise or settle. Formation of many small
specks seemed to have a tremendous effect on the speed with which subsequent
fermentation occurred. My guess is that these minute pectin specks provided
ready availability of yeast nutrients and/or a yeast transport mechanism (to
hold more yeast in suspension than normally could be held without
agitation). Since slow fermentation was my goal, this was decidedly
unfavorable.
The 17.4 g / 5 gal concentration of CaCl2 was based on supplier
recommendation (I'll dig up my notes and express this as ppm for anyone who
really needs it that way) . This concentration was based on commercial
cidermaking experience in France. I'll admit this sounded really high to
me. The 8 g / 5 gal was based on Andrew's recommended dosage of CaCl2 in
THE SCIENCE OF CIDERMAKING. Because there was a big difference in the
recommended dosages of CaCl2 the 12 g / 5 gal concentration was selected
more or less at random to be intermediate between them. The 5 g / 5 gal
concentration was selected to be more or less intermediate between Andrew's
recommended dosage and no dosage at all.
The principal control batch had no PME or CaCl2 added. There were also two
semi-control batches, one with a standard dose of PME added but no CaCl2,
and one with 5 grams of CaCl2 addition but no added PME. Aside from this,
the trial batches each received a standard supplier-recommended dosage of
PME and only the amount of CaCl2 was varied. The one with CaCl2 added (but
no PME) showed better early clarification than the control batch but was
much less clear than the batches to which PME and more generous additions of
CaCl2 (12 g / 5 gal or above) were added. The one with PME but no CaCl2
quickly became ultracloudy and stayed that way through fermentation. The
one with Andrew's recommended dosage didn't quite achieve full
precipitation, suggesting that the juice used may have had a higher pectin
content than assumed. When using PME and in doubt about pectin content, it
may be prudent to go with a higher concentration of calcium chloride.
Results also suggest it would be better to add no PME at all than to add PME
but then fail to add a sufficient amount of ionic precipitating agent such
as calcium chloride or calcium carbonate.
The gelled (or perhaps in some cases partially gelled) pectin seemed to be
pretty close to the must in density and tended not to rise or sink prior to
the beginning of detectable fermentation. Tiny bubbles seem to buoy it
upward. Preliminary trial results suggest that it won't settle to the top
or bottom bottom quickly enough to do you any good. You have to separate
the cider from the gel. Normally some sort of flotation is involved.
Commercially, nitrogen is bubbled from the bottom to force the gel to rise
to the top. More traditionally, carbon dioxide from the earliest stages of
fermentation will do the same thing. Once segregated, you must separate the
gel from the cider. You can do this by siphoning carefully from near the
bottom of the vessel. My recent experience suggests that you must have some
sort of flotation or effective segregation in order to remove the cider.
Otherwise, the "brain in a jar" quickly becomes a "brain drawn through a
tube" and every evasive maneuver of the siphon tube only stirs the gel more
and breaks it apart. I did manage to siphon a bit of the clear must
successfully, and am glad I did because of another problem that developed
later (described in a separate posting).
For this year's trials I'll probably continue with a single pressing of
Golden Russet to keep things as simple as possible and be more judicious in
selection of the geometry of the primary fermenter. I plan to focus on
separation of the gel by bubbling (natural flotation by fermentation CO2 vs.
bubbling with nitrogen at different gas flow rates and bubble sizes). In
addition I'll attempt separation of the precipitate (at high, low and zero
levels of added calcium ions) through centrifugation. The hypothesis being
tested here will be that high centrifugal force may be sufficient to
overcome ionic repulsive forces and relatively low difference in density and
help separate the pectin from the juice just as reliably as by flotation (if
not more so). Long Ashton experiments with centrifugation from around 1920
to the 1950's showed that centrifuging the juice too early actually
increases the rate of subsequent fermentation, while later centrifugation
retards it. The later work explained the retarded fermentation in terms
yeast removal/regrowth and of exhaustion of critical yeast nutrients. A
reasonable explanation of the opposite effect of early centrifugation never
seemed to be provided. If separation of the pectin with a centrifuge is
successful I'd like to explore the role of PME and CaCl2 as factors in
pectin precipitation (full and partial) and this precipitation's influence
on the rate of subsequent fermentation of juice that is separated by
centrifugation shortly after this treatment.
Gary
------------------------------
Subject: Re: Problems with 2004 PME keeve
From: "Gary Awdey" <gawdey@att.net>
Date: Thu, 29 Jul 2004 06:55:51 -0400
I used glass carboys for the preliminary PME trial since I like to see what
is happening, but this brought an entirely different issue to light. It is
tempting to fill the carboys reasonably close to the top in order to
minimize the volume of make-up juice you'll need to minimize ullage after
siphoning to another vessel (unless the second vessel is appreciably
smaller). If you fill the carboys to a level beyond the point at which the
top starts to curve inward to the neck (even if there still appears to be
plenty of room for a brown head to form) then you may be headed for
disaster. If the vessel is even slightly overfilled gas bubbles accumulate
at the top and move upward and inward along the sloping inner surface of the
carboy toward the neck. This causes some movement of the must (and gelled
pectin) in the same direction. Since the moving liquid doesn't continue up
into the neck with the escaping gas it must go somewhere else. Slow but
turbulent downward currents form in the center of the carboy , and these
carry the gelled pectin with it. If PME and calcium ions have caused a nice
precipitation of pectin then the gel is carried downward initially as big
clumps (very similar in appearance to a lava lamp). As vigor of the
fermentation increases (and it seems to increase remarkably quickly with
the gelled pectin present!) the pectin agglomeration gets pulled apart into
progressively smaller pieces, causing the formation of a foamy white head
rather than the desired brown head. In contrast, I've had much better
luck with formation of a brownhead in earlier and subsequent batches using a
vessel of different geometry (such as a cornelius keg, provided it still has
some head space). The principle here is that if bubbles must move along an
upper surface before escaping then you will be inducing currents that may
cause your keeve to fail.
------------------------------
Subject: Re: Availability of PME Sample
From: "Gary Awdey" <gawdey@att.net>
Date: Thu, 29 Jul 2004 06:55:59 -0400
Speaking of this year's trials, the time has come to make good on an earlier
promise to see who is interested in obtaining a trial sample of PME. It
turns out I was able to get samples from two different producers. I have
surplus PME and will gladly share with those who might be interested in
giving it a try, though if you have a larger trial in mind (thousands of
gallons) you can try asking the manufacturer(s) for your own sample. Just
email me offline (be sure to include your mailing address and a ballpark
estimate of how much cider you plan to make). It's easier on me if I can
repackage all that will be needed at the same time. (Maybe someone else can
request a freebie from a supplier in a year or two and return the favor).
Gary
------------------------------
End of Cider Digest #1152
*************************
