
Why green olives come in jars, but black ones come in cans - bilalq
https://www.marketplace.org/2014/05/05/business/ive-always-wondered/why-green-olives-come-jars-black-ones-come-cans
======
jaclaz
Maybe it is a local (US) thing, here in Italy/Europe you can find black olives
in glass jars just fine, a few examples:

[http://www.polli.it/prodotti/olive/olive-nere-
denocciolate-v...](http://www.polli.it/prodotti/olive/olive-nere-denocciolate-
vasetto/)

[http://shop.oliosalvagno.it/vasetto-olive-nere-in-
salamoia-g...](http://shop.oliosalvagno.it/vasetto-olive-nere-in-salamoia-
gr-280-salvagno.html)

[https://pietrasantaaltosalento.it/it/home/19-olive-nere-
in-s...](https://pietrasantaaltosalento.it/it/home/19-olive-nere-in-
salamoia.html)

~~~
captainmuon
Yeah, in Germany you can find both kinds in glasses, cans, or plastic pouches.
However, I think most black olives here are simply green ones, colored with
iron. I found it hard to find real black olives in my supermarket
unfortunately.

Also, I think the botulism issue is prevented by having an acidic environment.

~~~
aqsalose
Similar situation in Finland (except olives in plastic pouches I have yet to
see).

------
apo
As others have noted, the article doesn't seem to answer the question it
poses. What's missing is more detail around the process of producing green and
black olives.

Watch the end of the embedded video:

[https://youtu.be/xKWBJkaoRjM?t=1m7s](https://youtu.be/xKWBJkaoRjM?t=1m7s)

Black olives enter the canning facility unripe and green. Bubbling air
blackens them.

This part of the process isn't mentioned at all in the article, and it's hard
to know whether this was the process being used by Freda Ehmann, or
whether/how this oxygen treatment resulted in the botulism cases.

All in all, not the best in technical reporting.

~~~
sb8244
If you read into this more, it's actually the lye solution which artificially
ripens the olive. That Youtube video doesn't go into the lye process other
than the chart that you can see on the wall while going over the 7 day
process. My guess is they don't really want to be verbal that lye is used
(sounds a little gross to me).

However, the gap between why black olives are prone to botulism and green
olives are not prone is not covered. I wish that was expanded on.

~~~
Pica_soO
Olives are slightly acidic by nature and the lye neutralizes that? Neutral
environment, plus heat, plus low oxygen makes for Hollywoods funny faces.

~~~
sb8244
ah that seems likely! Thanks

------
jaclaz
This may give a "better" explanation (though still unsubstantiated):

[http://enquirer.com/editions/2001/06/25/tem_ask_a_stupid.htm...](http://enquirer.com/editions/2001/06/25/tem_ask_a_stupid.html)

[http://www.straightdope.com/columns/read/2885/why-is-it-
that...](http://www.straightdope.com/columns/read/2885/why-is-it-that-green-
olives-come-in-glass-jars-but-black-olives-come-in-cans)

[http://lacrossetribune.com/tomahjournal/lifestyles/ask-
your-...](http://lacrossetribune.com/tomahjournal/lifestyles/ask-your-science-
teacher-green-vs-black-
olives/article_6ae0713b-280e-5fe0-8c48-335f7cb2028e.html)

It seems more like it has become a tradition of some kind in California.

More here:

[http://oliveoilsindia.com/California-
Olives.htm](http://oliveoilsindia.com/California-Olives.htm)

it only applies to artificially made ripe olives.

~~~
jaclaz
Addition:

... and seemingly this "high temperature" sterilization (which is still within
110-120 degree Celsius, so perfectly doable in glass containers) adds
acrylamide:

[https://www.ars.usda.gov/research/publications/publication/?...](https://www.ars.usda.gov/research/publications/publication/?seqNo115=322472)

in almost unbelievable amounts:

[http://pubs.acs.org/doi/pdfplus/10.1021/jf5022829](http://pubs.acs.org/doi/pdfplus/10.1021/jf5022829)

Heck! 410 micrograms/Kg vs. 1.4 (Greek Olives) and 0 (Spanish Olives)!

[http://www.whfoods.com/genpage.php?tname=george&dbid=260](http://www.whfoods.com/genpage.php?tname=george&dbid=260)

>What About Acrylamide and Olives?

Research on olives and their acrylamide content has shown some inconsistency
over the past several years and this inconsistency has sparked controversy in
the public press about olives and their health risk with respect to
acrylamide. In data assembled by the U.S. Food and Drug Administration (FDA),
we've seen more than a dozen different kinds of olives, including Spanish,
Greek, Kalamata, Nolellata, Sicilian, d'Abruzzo, and Gaeta, and di Cerignola
that were determined to contain no detectable level of acrylamide. Yet we have
also seen FDA data showing levels of acrylamide as high as 1,925 ppb in some
canned, nationally distributed brands of black pitted olives. Based on this
data, we suspect that these higher acrylamide levels in select canned black
olives were related to specific handling, storage, processing (especially
preservation and darkening methods), and heating steps that favored formation
of acrylamide. It's also important to note here that we are not aware of any
data showing problematic levels of acrylamide in any extra virgin olive oils
available in the marketplace.

At present, we are not aware of any foolproof method that consumers can use to
avoid purchase of canned black olives that contain unwanted amounts of
acrylamide. Since the FDA data has shown no detectable levels of acrylamide in
numerous samples of important olives packed in brine, those olives may be
worth considering as options that may help avoid unwanted acrylamide. As
stated previously, extra virgin olive oil is another form of this nutrient-
rich food that, to our knowledge, has not been shown in research to contain
unwanted amounts of acrylamide.

~~~
subnaught
I won't pass judgement on whether 410 micrograms/kg is an "unbelievable"
amount, but I will just mention that it is 410 parts per billion, or less than
1 ppm.

~~~
jaclaz
Neither do I, but it is 400% the "traditional" olive contents, let's call it
"substantial increase".

The last cited article reports however that as much as 1,925 ppb have been
found in some specific canned olives.

~~~
WillPostForFood
For comparison, the FDA sampled a bunch of foods for acrylamide posted the
values here:

[https://www.fda.gov/food/foodborneillnesscontaminants/chemic...](https://www.fda.gov/food/foodborneillnesscontaminants/chemicalcontaminants/ucm053549.htm)

~~~
jonnathanson
Jesus, there is one Popeye's location that is apparently, just, like, going
out of its way to add acrylamide to its french fry oil or something.

This whole data set is oddly fascinating.

------
dkrich
I was surprised to read that the reason isn't that green olives are typically
used to make martinis. It seems to me that having a jar of olives on a bar
would make for a better appearance than a can. Also, green olives are
typically stuffed with pimentos or garlic or blue cheese, and so being able to
see them might help sell them, whereas black olives are used for things other
canned vegetables are used for, ie salads, casseroles, etc.

------
serg_chernata
Maybe my reading comprehension is shot but I didn't get a very clear answer to
the question at hand.

~~~
jaclaz
Nahh, the explanation is there, alright, though nothing supports the "240
degrees" theory (I have to presume they would be Fahrenheit degrees, i.e.
116-120 Celsius, and of course glass can bear that alright):

>The whole industry switched to a new standard for the ripe California olive.

"It has to be heated to 240 degrees. And only a can would tolerate that,
physically—you couldn’t do that with a glass jar."

Eventually, California olives came back. In cans.

Even if it was 240 Celsius (which I doubt), glass can bear it just fine.

~~~
pyre
> _of course glass can bear that alright_

Perhaps not in the 1920s though.

~~~
Symbiote
The setting point of jam is 105°C, so only very slightly cooler.

If I remember correctly from making jam with my mother, it's important to pour
the really hot jam into the heated jars to ensure everything stays sterile --
so the jam going into the jars is around 105°C.

~~~
sitharus
That's correct, but I've seen so many recipes on the internet that let the jam
cool so the jars don't crack. That's ok for making a small amount to eat
quickly, but for proper preservation you really need to do it hot.

~~~
Symbiote
It helps that my mother trained as a professional cook. That jam kept well for
years.

I also remember it very clearly, as jam-making was by far the most dangerous
cooking we ever did together. I could probably chart my maturity based on how
much I was allowed to help, starting from washing the jars and putting them in
the oven to sterilize, all the way to doing the whole process while she
watched.

------
alfanick
We need olives expert from HN - is this just USA (California) thing? I don't
believe that black olives in Europe are actually artificially dyed with iron
gluconate. My impression is that in Europe black olives are riped olives
picked in late autumn or winter. Anyone to confirm?

~~~
vkreso
Not an olive expert, but in Croatia (and probably the rest of Europe -
Mediterranean) AFAIK green olives are picked in autumn, and black ones, that
is full ripe ones, are picked in November and December. Those olives are used
for the production of olive oil and they give the oil it's distinct golden
colour... honestly, colouring olives sounds awful.

------
logfromblammo
If you're in a rush, it was because jarred ripe olives caused a botulism
outbreak, and only cans could tolerate the 240 degrees necessary to make them
safe for consumption.

------
shmerl
I'm missing something here. The article doesn't explain whether black color is
the result of artificial ripening or not, and why it creates a risk of
botulism (while green olives don't have it).

~~~
Tinyforebrain
Botulinum spores need * Low Oxygen * Low Salt * Low Acid

Green Olives are only processed by being in a high salt solution that also
contains some vinegar.(Or are lacto-fermented to create the acid.) Essentially
they are brine-pickles.

Black Olives are soaked in Lye(very alkaline) until they are uniformly soaked,
then put into a acid solution that helps develop their color(They are dark
normally, but not uniformly black). The brine is lower in salt also. In order
to make it safe for canning, they pressure can it to get to hotter than
240(I've always heard 250, but the article says 240).

Until the advent of modern polymer lined cans, salt would corrode the metal at
the concentrations in green olives. So I doubt its a Black = metal can thing
so much as...

* Automating pressure canning is easier/cheaper in metal. * Green Olives High salt, High acid, would corrode the metal. * Black Olives Lower salt, lower acid, could be metal canned.

~~~
shmerl
Thanks for the explanation!

------
drzaiusapelord
Are Kalamata olives not black? These are almost always sold in jars. I guess
according to Eataly black is only the California ripe olive. I imagine the
salami and olive expert who works at Eataly isn't going to comment on Greek
olives. He's still wrong. The article should be about California ripes, not
all black olives.

~~~
efficax
Kalamata olives are left to ripen to a deep purple (not black) on the tree,
and are cured like other olives (brine or oil). California olives start green,
and the curing process turns them black. See
[https://www.youtube.com/watch?v=xKWBJkaoRjM](https://www.youtube.com/watch?v=xKWBJkaoRjM)

------
vacri
Throwing my antipodean hat into the ring to add to the growing chorus of
"black olives come in jars".

------
rdtsc
You can just got to the international section or to stores which sell more
international food, specifically Mediterranean or Middle Eastern. There are
lots of varieties of olive, different sizes, packaged differently and so on.

------
feborges
I live in the Czech Republic and I can find both in glass jars.

------
Camillo
So _all_ black olives in the US are artificially ripened?

~~~
djrogers
No, only the “California Ripe” variety

------
tim2387
Hmmm. I almost always buy black olives packed in jars.

------
jxramos
I find the account of the epidemiology investigation very intriguing with the
whole seating chart and all. Cool stuff.

------
synicalx
I've literally never seen a "can" of olives, is that normal in some weird part
of the world?

------
acehreli
The article is not about olives, rather about those black things that
Californians eat on pizza and some salads. They neither look like nor taste
like olives. :p

