Pectic problem or bottom keeve
Claude Jolicoeur
see the picture of a 5 gallon carboy with a pectic haze or gel in the
bottom half. We sometimes call this a bottom keeve.
This disorder sometimes happen to my ciders. When it does, it starts to
appear after the fermentation stops and the cider is dry, as the cider
clears. As you can see, all the top is nery nice and clear cider, while the
bottom half is not quite so appealing... Sometimes, the pectic gel is more
compacted in the bottom and only occupies about 20% of the volume - this is
not so bad. But when half or more of the cider is spoiled (well, not really
spoiled as there are other uses for it) I am not so happy about it...
I wonder if some enzyme or something could break this gel so it would
compact itself at the bottom and then the loss could be minimised. Andrew,
would you have an idea? Could pectinase do something? Or if pectinase was
used at the beginning - before the start of fermentation, could it prevent
this to happen?
Thanks for any input,
Claude Jolicoeur
Andrew Lea
>
> I wonder if some enzyme or something could break this gel so it would
> compact itself at the bottom and then the loss could be minimised. Andrew,
> would you have an idea? Could pectinase do something? Or if pectinase was
> used at the beginning - before the start of fermentation, could it prevent
> this to happen?
What a classic, Claude! Yes that is a pectin gel. It is caused by the
pectin aggregating and precipitating in the presence of alcohol. As you
suggest, a regular multi action winemaker's pectinase (containing PME,
PG and maybe PL activities) will tackle it. However, it is best to add
the enzyme before fermentation. The reason is that the enzyme is
inhibited quite severely in the presence of alcohol.
Andrew
--
Wittenham Hill Cider Page
http://www.cider.org.uk
Claude Jolicoeur
On curing it, Andrew says pectinase is inhibited by alcohol - does it
mean that I should increase the dosage of pectinase to get an effect,
or make more than one pectinase treatment, or simply accept that any
quantity of pectinase will only have a very limited effect. Would pure
PME (I still have some) be more efficient than pectinase?
On preventing it, I suspect that a keeve with PME would prevent it
just as well as a pectinase treatment before fermentation. Anything
else could prevent this gel?
On understanding it, I view this pectic gel as a very close cousin to
the chapeau brun. Probably that the batches that do produce the gel
would have made successful keeves if the keeving process would have
been triggered by some calcium salt. What could be the effect of
adding calcium salt now? (with or without pectinase or PME). What I
don't understant is what makes some batches produce the gel and others
not. I have not yet found a factor common to the gelled batches that
would not be present in the other, normal, batches.
What would you think of this strategy:
- systematically add a bit of calcium salt to the juice
- if the keeve starts by itself (without adding PME), then go for it,
if it doesn't start by itself, then the pectic gel most likely would
not form at the end of the fermentation process.
Does it makes sense?
Claude
Andrew Lea
> On curing it, Andrew says pectinase is inhibited by alcohol - does it
> mean that I should increase the dosage of pectinase to get an effect,
> or make more than one pectinase treatment, or simply accept that any
> quantity of pectinase will only have a very limited effect.
Yes and yes. Try adding double the recommended amount and see what
happens after a week in a warmish place. If nothing, try again!
> Would pure PME (I still have some) be more efficient than pectinase?
No. You *must* have a combination of PME and PG at very least (i.e.
so-called 'pectinase'). The first strips off the methyl groups, the
second depolymerises the demethylated pectin and cuts it up into small
soluble bits. PME is native to the apple, and many fermenting yeasts
have PG. Hence this clarification often occurs naturally without anyone
noticing.
>
> On preventing it, I suspect that a keeve with PME would prevent it
> just as well as a pectinase treatment before fermentation.
It will prevent it as long as you remove the juice from the chapeau
brun. That is, you must physically remove the calcium pectate gel.
> Anything else could prevent this gel?
Yes a broad spectrum 'pectinase' added to the juice (as mentioned before)
>
> On understanding it, I view this pectic gel as a very close cousin to
> the chapeau brun. Probably that the batches that do produce the gel
> would have made successful keeves if the keeving process would have
> been triggered by some calcium salt. What could be the effect of
> adding calcium salt now? (with or without pectinase or PME).
The two are close but not the same. During keeving you strip the methyl
groups, create pectic acid, and complex it to a gel with calcium. i.e.
you create insoluble 'calcium pectate' (aka chapeau brun)
But what you have here is an alcohol-insoluble precipitated gel of
native (i.e. fully methylated) pectin.
Adding PME and calcium at this stage *might* cause the gel to firm up
some more and make it easier to remove. It will still be insoluble. But
if you use a PME / PG mix (and no calcium) it should more or less
dissolve away.
>
> What would you think of this strategy:
> - systematically add a bit of calcium salt to the juice
> - if the keeve starts by itself (without adding PME), then go for it,
> if it doesn't start by itself, then the pectic gel most likely would
> not form at the end of the fermentation process.
> Does it makes sense?
Not sure I understand you! Whenever you have extra calcium, you will
likely end up with an insoluble gel at some time. If you don't need /
want to keeve, and don't want the gel to form after fermentation, just
pre-treat your juice batches with a mixed 'pectinase'. Or use just the
PME (without calcium) and hope that the yeast produces enough PG to
depolymerise the pectin during fermentation. Winemaking 'pectinases' are
so easy to buy that it's simpler just to add it as a preventative measure.
Claude Jolicoeur
> Yes and yes. Try adding double the recommended amount and see what
> happens after a week in a warmish place. If nothing, try again!
for the moment.
And if nothing hapens after a second trial, I might try some calcium
salt to firm it up and maybe compact it - it would then be possible to
rack and loose less cider.
What would filtering or fining do to such a cider?
> > On preventing it, I suspect that a keeve with PME would prevent it
> > just as well as a pectinase treatment before fermentation.
> It will prevent it as long as you remove the juice from the chapeau
> brun. That is, you must physically remove the calcium pectate gel.
> > Anything else could prevent this gel?
> Yes a broad spectrum 'pectinase' added to the juice (as mentioned before)
> so easy to buy that it's simpler just to add it as a preventative measure.
understood!
but what I meant when I wrote this:
> > What would you think of this strategy:
> > - systematically add a bit of calcium salt to the juice
> > - if the keeve starts by itself (without adding PME), then go for it,
> > if it doesn't start by itself, then the pectic gel most likely would
> > not form at the end of the fermentation process.
> > Does it makes sense?
and this salt does not trigger a keeve, then presumably the gel would
not form itself either at the end of the fermentation - but maybe I am
wrong and both phenomenoms are not interrelated in such a way.
Where I am lost however, is in the understanding of why one batch of
cider will develop the gel and another one will not develop it. It has
to be something that is present in the juice from the beginning - is
it because of a variety that contains more pectin, or more or less of
a certain enzyme? Is there a simple test that could be done right
after pressing that would tell if a gel is likely to form itself 6 to
12 months later?
Ideally, it would be something like this:
Add a drop of some solution to 100 ml of the juice - if it turns red,
it means the gel is likely to form - and if it turns green, then there
is no risk of such a gel to happen - Would be nice wouldn't it?
Claude
Andrew Lea
>
> First pectinase shot is in as of this afternoon. We just have to wait
> for the moment.
> And if nothing hapens after a second trial, I might try some calcium
> salt to firm it up and maybe compact it - it would then be possible to
> rack and loose less cider.
> What would filtering or fining do to such a cider?
Filters clog up and fining does not usually work on gels, only on
charged particles. That is why people use pectinases.
>
> is that if I add some calcium salt to the juice just after pressing
> and this salt does not trigger a keeve, then presumably the gel would
> not form itself either at the end of the fermentation - but maybe I am
> wrong and both phenomenoms are not interrelated in such a way.
No it does not follow. If the pectin is not demethylated by a PME, it
cannot gel with added calcium (because it is still pectin, not pectate).
But the pectin will still be present and will be precipitated by alcohol
after fermentation.
>
>
> Where I am lost however, is in the understanding of why one batch of
> cider will develop the gel and another one will not develop it.
It could either be the presence /ábsence of pectin itself and / or the
presence / absence of PME in the apple and PG in the yeast.
The simplest thing is to destroy the pectin in the first place (using
pectinase).
> Is there a simple test that could be done right
> after pressing that would tell if a gel is likely to form itself 6 to
> 12 months later?
>
Yes. You can test for the presence of pectin in the juice by adding 3
parts of alcohol* to 1 part of juice. Shake well and stand for 30
minutes. If a thick gel has formed, there is plenty of pectin. If only a
few wisps or strands, there is much less.
* In the UK we use the denatured (not-for-drinking) alcohol called
'methylated spirit', or 'surgical spirit'. Not sure what you call it in
Quebec.
Claude Jolicoeur
> * In the UK we use the denatured (not-for-drinking) alcohol called
> 'methylated spirit', or 'surgical spirit'. Not sure what you call it in
> Quebec.
can buy it at 70% or 90% in drugstores and it is normally used as an
antiseptic cleanser.
Claude
Andrew Lea
It's not the same - isopropanol is a different alcohol than ethanol -
but it will work OK (maybe even better!) in the test. Buy the 90% version.
The others I mentioned are different types of 'denatured' ethanol. [My
French dictionary gives 'alcool a bruler' for the term used in mainland
France]
Claude Jolicoeur
Is there a difference between the pectic gel and the pectic haze you
write about in your book? I would assume the gel would be an extreme
form of the haze. Am I correct in thinking that the haze only affects
the clarity of the cider while the gel also affects the consistency,
making it like a soft jello. Interestingly I very seldom experience a
cider with a haze - only when there is a large proportion of pears -
but then it has been reported in the literature that perry doesn't
clarify as easily as cider.
You write in the book that the pectic haze mostly occurs when dessert
apples are used and when overripe. Do these conditions also apply for
the gel?
Claude
Andrew Lea
> Andrew,
> Is there a difference between the pectic gel and the pectic haze you
> write about in your book? I would assume the gel would be an extreme
> form of the haze.
I think that is right. The more pectin the more gelatinous it tends to
be. Smaller amounts of pectin I think get trapped or associated with
other sorts of debris making it more of a haze than a gel.
> Am I correct in thinking that the haze only affects the clarity of the cider while the gel also affects the consistency,
> making it like a soft jello.
I would say so.
Can I just be sure that the 'jello' part just refers to the gel? The
rest of the cider above it is OK, right, not viscous or gelatinised
throughout?? [I just want to be sure we are not dealing with an extreme
case of ropiness / oiliness here which would be caused by lactic acid
bacteria dextran gel not a pectin gel].
> You write in the book that the pectic haze mostly occurs when dessert
> apples are used and when overripe. Do these conditions also apply for
> the gel?
I think so. Full pectin gels like yours are not so common. It is
difficult to be sure of the reason, since there is an interplay of
several factors here... pectin levels, extent of PME and PG activity,
polyvalent metal ions (Ca++, Mg++, Al+++ ....).
Claude Jolicoeur
> Can I just be sure that the 'jello' part just refers to the gel? The
> rest of the cider above it is OK, right, not viscous or gelatinised
> throughout?? [I just want to be sure we are not dealing with an extreme
> case of ropiness / oiliness here which would be caused by lactic acid
> bacteria dextran gel not a pectin gel].
more), the gel settles and gets more compact in the bottom, occupying
20 to 25% of the carboy. I can then rack the top and bottle it. This
has given me some of my best ciders. I use the bottom gel in the
kitchen as cooking cider - excellent for sauces, marinades, etc...
>Full pectin gels like yours are not so common. It is
> difficult to be sure of the reason, since there is an interplay of
> several factors here... pectin levels, extent of PME and PG activity,
> polyvalent metal ions (Ca++, Mg++, Al+++ ....).
with the Cider Digest 4 or 5 years ago, my ciders were among the most
successful in producing a nice and firm chapeau brun. I remember you
were even surprised when I told you I had a successful keeve with
dessert apples that had high acidity level. I haven't had a failure
yet from all the keeves that I have attempted. I can't help in
thinking that there must be something in some of the varieties that I
routinely use that promote a successful keeve, but at the same time
make the cider vulnerable to the pectic gel. Something in the pectin
concentration or natural PME level, probably. We already know the N
level of my apples is much lower than avereage, but this should be
irrelevant in this case. I think I will try in one of my later batches
this fall a keeve without adding PME - just calcium salt. It will
probably work fine.
Claude
Andrew Lea
>
> It is interesting that when you and Gary organised this keeving test
> with the Cider Digest 4 or 5 years ago, my ciders were among the
> most successful in producing a nice and firm chapeau brun.
They were indeed.
> I remember you were even surprised when I told you I had a successful
> keeve with dessert apples that had high acidity level. I haven't had
> a failure yet from all the keeves that I have attempted.
You are a lucky man!
> I can't help in thinking that there must be something in some of the
> varieties that I routinely use that promote a successful keeve, but
> at the same time make the cider vulnerable to the pectic gel.
> Something in the pectin concentration or natural PME level, probably.
>
D'accord!
> We already know the N level of my apples is much lower than avereage,
> but this should be irrelevant in this case. I think I will try in one
> of my later batches this fall a keeve without adding PME - just
> calcium salt. It will probably work fine.
And I shall be interested to know the result of your 'alcohol test' too.
Andrew
PS Have you any idea if keeving is / was a traditional technique in
Quebec cider making, as it was and still is in France (even though the
varieties are different? Are there any 'native' i.e. Norman / Breton
origin bittersweets in Quebec?)
Claude Jolicoeur
Andrew Lea wrote:
> PS Have you any idea if keeving is / was a traditional technique in
> Quebec cider making, as it was and still is in France (even though the
> varieties are different? Are there any 'native' i.e. Norman / Breton
> origin bittersweets in Quebec?)
not forget that we became an English colony in 1760 - from that date
the French influence stopped. There are very few French apples
varieties remaining from the old colony (they necessarily have to be
older than 1760) and none are cider apples as far as I know. Most
history books say that cider was done in the old French colony, but I
haven't seen one that detailed the process used at the time. Then,
during the period 1910-1970, cider was not legal in Quebec, although
it was done in the farms, it could not be sold, and thus there is very
little information on how it was done. I rather suspect that the
methods used to make cider during the 1800 and most of 1900 would have
been similar to those used in New England, with essentially the same
varieties.
There is a short summary of the history of Quebec cider there:
http://wapedia.mobi/en/Quebec_cider
Claude
Dick Dunn
might comment. Specifically, two batches from 2007 developed a deposit
that sounds similar to Claude's, and because of one of them with some
advice from Andrew, I treated a batch from 2008 with pectinase early on,
and had only one bottle out of 8 cases (96) showing any significant
pectin.
I've seen slight deposits in various of my ciders all along, but hadn't
thought to do anything about them since they had no ill effect on the
taste and it was easy enough to decant away from the deposit. But with
the first "commercial" batch, which was also the first in clear bottles,
it became a problem.
The deposit I saw in the two batches (both in clear bottles so I could
see it without disturbing) had a gelatinous look. Sorry if that seems
a leading observation, but it really did look like thin or poorly-set
gelatin. Disturbed slightly, it would cohere and lift up, but shear
into large-ish pieces. (This is talking about maybe 5-10 mm at the
bottom of a punted 750 ml bottle.) Agitating would break it up into
somewhat cloudy-chunky bits which would eventually settle down again.
The deposit was translucent and uncolored (even with the cider having
a fair gold color).
Anyway, after having that in the 2007 commercial batch and as a result
having to rebottle it (!), I gave a good dose of pectinase in 2008 and
didn't have a problem.
The curious aspect, to me, was that the ciders with the gel had been
effectively clear for many weeks before bottling, yet the pectin (if
I'm correct that's what it is) still formed in bottle.
--
Dick Dunn rc...@talisman.com Hygiene, Colorado USA
Andrew Lea
>
> The curious aspect, to me, was that the ciders with the gel had been
> effectively clear for many weeks before bottling, yet the pectin (if
> I'm correct that's what it is) still formed in bottle.
This is often the case with hazes and deposits in drinks. Due to their
complex chemical nature and the consequent existence of what are known
as 'protective colloids', it is often possible for nominally insoluble
material to remain 'supersaturated' for months, even years. Then,
usually following some thermal or physical shock (eg a cold snap or
bottling), or some event which allows for nucleation (e.g. the act of
filtration itself), it all tumbles out of solution and won't go back in.
Tartrate in wine is the best known commercial example of this. I have
seen liquids go in one side of a filter totally clear and come out the
far side completely cloudy! It also takes time for hazes to grow from
single large molecules to a size big enough to be visible to the eye.
Generally, anything less than 0.1 micron in size won't be, and Brownian
motion, electrostatic repulsion and convection currents existing in the
container may mean that aggregation is very very slow initially.
Andrew
Claude Jolicoeur
> I've had some problems similar to what Claude describes; Andrew suggested I
> might comment. Specifically, two batches from 2007 developed a deposit
> that sounds similar to Claude's, and because of one of them with some
> advice from Andrew, I treated a batch from 2008 with pectinase early on,
> and had only one bottle out of 8 cases (96) showing any significant
> pectin.
or less thick. I have never worried too much about it, but as Dick
says, it may become annoying in a commercial setup.
When you use the pectinase before fermentation, do you pitch the yeast
about the same time or do you wait until there is a deposit and rack
before starting the fermentation?
Claude
Dick Dunn
> Dick Dunn wrote:
> > I've had some problems similar to what Claude describes; Andrew suggested I
> > might comment. Specifically, two batches from 2007 developed a deposit
> > that sounds similar to Claude's, and because of one of them with some
> > advice from Andrew, I treated a batch from 2008 with pectinase early on,
> > and had only one bottle out of 8 cases (96) showing any significant
> > pectin.
> When you use the pectinase before fermentation, do you pitch the yeast
> about the same time or do you wait until there is a deposit and rack
> before starting the fermentation?
I added the pectinase immediately after filling the fermenter. I sulphited
about the same time, so of course I waited (a day or so) to add yeast. I
didn't rack the first time until fermentation was mostly done and settling
down.
My understanding was that the pectinase is breaking up the pectin, not
precipitating/settling it. Did I misunderstand that part?
Andrew Lea
>
> I added the pectinase immediately after filling the fermenter. I sulphited
> about the same time, so of course I waited (a day or so) to add yeast. I
> didn't rack the first time until fermentation was mostly done and settling
> down.
>
> My understanding was that the pectinase is breaking up the pectin, not
> precipitating/settling it. Did I misunderstand that part?
>
No, Dick, you are right. The action of a combined pectinase is twofold:
1. The PME removes the methyl side chins from the pectin (methylated
polygalacturonic acid).
2. The PG then cleaves the polymer into individual galacturonic acid
units. These are soluble and remain so for ever.
Andrew
Ray Blockley
"My understanding was that the pectinase is breaking up the pectin, not
precipitating/settling it. Did I misunderstand that part?"
No, that's correct. Pectic / Pectin enzymes break down the pectin and reduce
any chances of not only a pectin gel forming, but also ensures there is no
pectin haze. It doesn't form any form of "precipitate".
I used to make a lot of strawberry, plum and damson wines, and the pectin
that makes them great for jam makes them a nightmare during fermentation...
I never had any problems at all by using a good dose of pectin enzyme.
Cheers,
Ray Blockley
> No, Dick, you are right. The action of a combined pectinase is twofold:
>
> 1. The PME removes the methyl side chins from the pectin (methylated
> polygalacturonic acid).
>
> 2. The PG then cleaves the polymer into individual galacturonic acid
> units. These are soluble and remain so for ever.
Just curious: does the action of the enzyme in breaking down the pectin into
galacturonic acid affect the pH at all? Or is this already detected by an
acidity test? Or is the pH effect negligible?
Andrew Lea
>
> Just curious: does the action of the enzyme in breaking down the pectin into
> galacturonic acid affect the pH at all? Or is this already detected by an
> acidity test? Or is the pH effect negligible?
Good point but no it doesn't (much). Galacturonic acid is quite a weak
acid compared to the predominant malic acid, and the system is quite
well buffered, so any pH or acidity shift is pretty negligible. Just
about measurable in a lab, but of little practical significance, and
probably less than the potential effect of fermentation itself on
acidity (yeasts do metabolise organic acids to greater or lesser extents).
What the free galacturonic acid does do (harking back to parallel
thread) is to increase the sulphite binding power of the juice though.
If you go to the third tab of
http://www.cider.org.uk/sulphite_binding.xls and change the galacturonic
acid level from 1000 ppm (typical background) to 10000 ppm (possible
after pectinase treatment) you will see the numerical effect. That's one
reason I say that all the SO2 charts and tables in the world are only
rule-of-thumb guides!
Claude Jolicoeur
> > My understanding was that the pectinase is breaking up the pectin, not
> > precipitating/settling it. Did I misunderstand that part?
>
> No, Dick, you are right. The action of a combined pectinase is twofold:
ago, and within a few days, the juice had perfectly clarified (a bit
like commercial apple juice you buy in stores) and there was a nice
deposit in the botom of the container - I could then rack the juice
and pitch the yeast to start fermentation.
I always thought pectinase was used commercially to clear apple
juice...
Claude
Andrew Lea
> I always thought pectinase was used commercially to clear apple
> juice...
It is. Of course there is always likely to be some deposit once the
pectin is destroyed and the juice viscosity is lowered, but that could
be all sorts of things - bits of apple flesh, cell debris, protein,
oxidised tannins, starch....etc. Degraded pectin will probably only be
a small part of it. There are things called 'hairy side chains' (!) in
apple pectin which are not part of the (poly)galacturonic acid backbone
and these may drop out of solution after depolymerisation.
Thanks for all that interesting info on Quebec cider by the way. I
hadn't realised the 'prohibition' had lasted so long and that the
historical links had been virtually broken.
Claude Jolicoeur
> And I shall be interested to know the result of your 'alcohol test' too.
I pressed some juice this weekend and made an 'alcohol test' to evaluate
the pectin content as per Andrew's recommendations in his message of Oct 2.
The test was done on the resulting blend before adding anythig else.
It wasn't easy, but I managed to take a picture (attached) of the result.
As we can see on the picture, there are some sorts of strands of pectin in
the liquid, but no thick gel was formed - liquid remained liquid and fluid.
I have 2 batches of this blend: to one I added pectinase and is started the
usual way with a yeast culture, and the other was simply inoculated with
calcium salt without PME - to see the chapeau brun will form by itself.
By the way, I finally got a reply from Standa about Klercidre. The price of
the kit is quite reasonable, at around 11 EUR for 500 litres as it was
already mentioned, but they charge 53 EUR for shipping to Canada! I just
couldn't believe it. Anyway, it's too late now for this year. For next
year, I will probably have some shipped to friends in France who will just
take the small PME container and mail it to me...
Claude
Dries Muylaert
Andrew Lea wrote:
> And I shall be interested to know the result of your 'alcohol test' too.
I pressed some juice this weekend and made an 'alcohol test' to evaluate
the pectin content as per Andrew's recommendations in his message of Oct 2.
The test was done on the resulting blend before adding anythig else.
It wasn't easy, but I managed to take a picture (attached) of the result.
As we can see on the picture, there are some sorts of strands of pectin in
the liquid, but no thick gel was formed - liquid remained liquid and fluid.
I have 2 batches of this blend: to one I added pectinase and is started the
usual way with a yeast culture, and the other was simply inoculated with
calcium salt without PME - to see the chapeau brun will form by itself.
Claude Jolicoeur
> You must keep the yeast activity low by maintaining 6-10 Celsius. Btw, did
> you ad sulfide? If so don't use high dosage.
time without adding the PME enzyme. I will let it go a few days, but
if nothing happens, I will add some enzyme (I still have a bit left
from previous years). I just want to know if I really need the enzyme
to get the chapeau brun. If I find that I don't need it, I will not
bother anymore trying to buy some from France and paying ridiculous
shipping charges...
Claude
Dries Muylaert
jez....@btinternet.com
Hmmmmm. Will now have to go back through all those pectin posts eh!
Jez
PS - thanks for the location Claude, will try to update the map today
Sent from my BlackBerry® wireless device
Dries Muylaert
Just to say that I also have a one-two inch pectin layer on top of my cider. However this is in a batch of 340 litres of juice! I have capacity to rack it off,
Andrew Lea
> If you
> leave things as they are (no racking) the lot will go back into the most
> and fermentation will be faster.
> [Jez]
> but wonder if its practical to either scrape the layer off the top
> or simply let it slowly ferment away (the capping does seem to have
> slowed the fermentation down a lot).
You may be able to remove the cap ('flying lees') with a slotted spoon
or perforated strainer if it is compact enough. If you just let it
ferment away, the cap will drop back as Dries says. Once it collapses
back into the cider you have gained nothing (assuming you want a nice
slow fermentation) because it will put all the trapped nutrients back.