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Jelly, jam and candy
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Jack Schmidling



Joined: 22 Jun 2014
Posts: 4
Location: United States

PostPosted: Mon Jun 23, 2014 6:17 pm    Post subject: Jelly, jam and candy Reply with quote

I can't cook without a calculator, IR thermometer and pH meter so I guess that qualifies me as a cooking engineer.

I have never quite understood the physics of jelly making and there seems to be something inconsistent with the standards methods.

One takes a juice without enough sugar and adds big bunches of sugar and then boils it down to concentrate the sugar and presumably to concentrate the juice.

The amount of sugar added is proportional to the amount of juice we start with.

This is usually done at a vigorous boil while monitoring the temp until it reaches a specific temperature. This is time consuming, messy and full of booby traps.

The net result is some amount of jelly based on the water to sugar ratio determined by the boiling point.

Seems like we could take the juice and reduce it down to some concentration we like the taste of, add the "proper" amount of sugar and bring this to a boil and it's done.

If we reduce the juice and calculate the sugar in the traditional way, we would need much less sugar and end up with much less jelly.

Something is missing here and the only thing I can think of is that there must be water in the sugar that has to be reduced.

Any thoughts?

Jack
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Dilbert



Joined: 19 Oct 2007
Posts: 1026
Location: central PA

PostPosted: Mon Jun 23, 2014 6:50 pm    Post subject: Reply with quote

is this specifically about jelly?
because.... the plot thickens....

we got:
jelly
jam
preserves
marmalade

"thickening" results from two things -

pectin is one. the thinner/less viscose the 'stuff' is, the more important is the role of natural or added pectin.

sugar is the other - not only by the % of sugar - but heating sugar makes it behave differently when it cools - from soft to brittle teeth breaking hardness.

the high sugar content is also the preservative agent. back-in-the-day.... we would make jelly/jam/preserves/marmalade, into the jar, cool, top off / seal with paraffin wax, stored at room temp.

commercially it's now pasteurized / sterilized / whatever; home cooks can use a pressure canner if they want to go there.

for "jelly" as a single thing, mebets the sugar % etc could fall into a narrow range. going up the scale the stuff gets thicker - by definition and design. the % and temps are likely not to to be 'the same' as for jelly.

and the fruit under process may also require different specs.

it's not an 'accident' that jam is thicker & lumpier than jelly. and the amount of water and sugar and pectin in the fruit 'as started with' will determine how much more sugar one needs.

my grandmother did not have gadgets. she had a coal stove. she'd get the stuff to boiling, add sugar, eventually just plain old taste it to see if it was sweet enough for her liking.

then it would continue to heat/boil - she would spoon out some of the syrup and drizzle it into a glass a cold water. she had a calibrated eyeball from long experience.....
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Jim Cooley



Joined: 09 Oct 2008
Posts: 346
Location: Seattle

PostPosted: Tue Jun 24, 2014 1:05 pm    Post subject: Reply with quote

Quote:
sugar is the other - not only by the % of sugar - but heating sugar makes it behave differently when it cools - from soft to brittle teeth breaking hardness.


Dilbert, can you elaborate on this?

I take it to mean that the hotter the sugar/fruit/pectin mixture gets, the thicker the end result?

I have trouble with jams setting well, they usually end up too runny. I also don't like a lot of sugar, so use the minimal amount required but make sure I have plenty of pectin.

From what you're saying, it sounds like I'm simply not heating the mixture hot enough.

I do have a candy thermometer around here somewhere, but never tried it, and have discovered my electronic one is miscalibrated. You guys are going to make me by a Thermopen yet!
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Dilbert



Joined: 19 Oct 2007
Posts: 1026
Location: central PA

PostPosted: Tue Jun 24, 2014 1:54 pm    Post subject: Reply with quote

if you check the candy thermometer, it probably has "stage" notations like

thread
soft ball
hard ball
soft crack
hard crack
...I'm missing one.... but whatever

so - yes, it relates to temperature and it relates to water content because the hotter it's heated the more water is driven out of the sugar. less water = not only thicker, but physical difference of how the sugar 'sets up' - taken to the end point of "hard crack" teeth shattering stuff.

just "boiling" doesn't work because up to a point there's enough water in the sugar mix (ie jelly / jam ...) that the water is boiling but the temp does not increase significantly. similar to sweating down / saute - as the water content is reduced the temp starts to climb - whether that's because the oil in the saute pan heats past 212'F or the sugar heats past 212'F - with "too much" water in the pan/pot, the temps cannot increase much over 212'F.

be aware: depending on your heat source, sugar temp can 'spike' quite rapidly. working with sugar is best with a liberal dose of patience - it's very good at burning the living daylights out human skin.

explains & pix here:
http://www.exploratorium.edu/cooking/candy/sugar-stages.html
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Jack Schmidling



Joined: 22 Jun 2014
Posts: 4
Location: United States

PostPosted: Tue Jun 24, 2014 4:40 pm    Post subject: Reply with quote

Not quite sure where pectin fits in but one can and usually does, make candy without it.

Reading the cited thread and one on the boiling point of sugar just adds to the confusion.

There supposedly is no boiling point for sugar but the boiling point is key to making jelly and candy.

The key is that what we call sugar is really a high concentration of sugar in water.

"1. Soft-Ball Stage
235 F240 F
sugar concentration: 85%"

Means that there is 15% water in the sugar at that point.

Question is, what percent of what we call sugar is water?

You usually add water in the form of juice for jelly so we have to reduce the total water content to the jelly point.

If there was no water in the starting sugar, one could simply add the amount of water necessary to get the correct concentration for jelly and dissolve it and have jelly.

This does not work because of the water in the sugar.

So this can only be engineering or science if we know how much water is in granulated sugar.

js
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Jim Cooley



Joined: 09 Oct 2008
Posts: 346
Location: Seattle

PostPosted: Tue Jun 24, 2014 6:28 pm    Post subject: Reply with quote

Thanks Dilbert.

Blackberry season is soon upon us and I was dismayed and disappointed last time I tried to make jam/preserves. (actually, it was cherries, but same difference). Over the years, sometimes the jams come out perfectly and other times they don't.

Will review my OLD cookbooks to figure out how much crack I need for the mixture to set properly.

Err, I mean the ideal temp. Might even write a letter to the Sure-Jell folks, because not only will I get a reply, but they will throw in coupons....

Thanks also for the warning re heating. One of those times I'll pull out my butane gas burner instead of the cheap electric range I have.
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Dilbert



Joined: 19 Oct 2007
Posts: 1026
Location: central PA

PostPosted: Tue Jun 24, 2014 9:11 pm    Post subject: Reply with quote

yeah, I've seen a lot of recipes that just toss in X of this and Y of that, boil for Z minutes, and . . .

"...sometimes the jams come out perfectly and other times they don't."

the "most opinion" centers around getting the mix up to min. 220'F
altitude plays a role.
the 'range' seems to be 220-225'F

there is some wiggle room in the temps. - it's not like you have to hit it to the tenth.

there is of course the "acid test" - spoon some out into a heat proof glass bowl and chill in an ice bath to see if it sets up or sets down....
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Dilbert



Joined: 19 Oct 2007
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Location: central PA

PostPosted: Tue Jun 24, 2014 9:18 pm    Post subject: Reply with quote

Jack -

pectin is natural thickener present in fruit 'stuff' - the fruit itself contains pection (well, most of them, not all - some research required)
depending the year, the weather, the fruit, the variety of the fruit, etc the natural pectin levels will vary.

a lot of people seeking to get into a jam use some extra pectin, just to be sure.

"There supposedly is no boiling point for sugar but the boiling point is key to making jelly and candy. "
no, not actually. for the sugar, it's not the boiling point that anyone is after, it is a temperature of the sugar mixture.

www.tis-gdv.de - "The water content of white sugar is at most 0.075%."
see also:
http://static.fishersci.com/cmsassets/downloads/segment/Scientific/pdf/MettlerToledo/11795881_sugar_industry.pdf
www.agrodev.com/doc/SUGAR%20SPECIFICATIONS.doc
http://www.genesisny.net/Commodity/Sugar/SSpecs.html

what you may perceive as "boiling" is water turning to steam and bubbling up thru the sugar syrup.
if one pays attention to the temperature of the mix, it is not necessary to know how much water is in the fruit, the sugar, or added along the way somewhere.
the 'excess' water absorbs a lot of heat to turn to steam, absorbing that heat cools the sugar mixture, until enough water has been forced out the the sugar mixture that the sugar mixture reaches the desired temperature.

"If there was no water in the starting sugar, one could simply add the amount of water necessary to get the correct concentration for jelly and dissolve it and have jelly. "
no. if you add 15 pounds of water to 85 pounds of sugar, you will have an 85% sugar solution. however if it is not heated to the specified temperature, it will never be anything other than a goopy mix of sugar and water.

heat causes change in sugar behavior - that is the point you may be missing.

if you check the links above, you'll see the water content in white table sugar on the order of 0.04% to max 0.075%
so in that 85 pounds of sugar, you'll have 0.0004*85=0.034 lbs of water = 0.544 ounces by weight or roughly a tablespoon of "extra" water on the low end, or double that on the high end.
so in the 85lbs sugar + 15 lbs water example, 15 lbs of water at room temperature is about 454 tablespoons of water; not sure +/- 1 tablespoon is going to be critical.
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Jack Schmidling



Joined: 22 Jun 2014
Posts: 4
Location: United States

PostPosted: Wed Jun 25, 2014 1:02 am    Post subject: Reply with quote

Dilbert wrote:
Jack -

pectin is natural thickener present in fruit 'stuff' - the fruit itself contains pection (well, most of them, not all - some research required)
depending the year, the weather, the fruit, the variety of the fruit, etc the natural pectin levels will vary.


I know what pectin is but not sure what part it plays. My wife says if you use pectin, you don't have to pay any attention to the candy thermometer. Just bring to a boil and it's pretty much done.

If this is true, I have been living a delusion.


> for the sugar, it's not the boiling point that anyone is after, it is a temperature of the sugar mixture.

It's a chicken and egg thing. The temp is the boiling point of that particular concentration. The more water boiled away the more we approach the boiling point of sugar which the physicists say does not exist.

More later will check the links.

js
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Jim Cooley



Joined: 09 Oct 2008
Posts: 346
Location: Seattle

PostPosted: Wed Jun 25, 2014 9:27 am    Post subject: Reply with quote

Dilbert wrote:

there is of course the "acid test" - spoon some out into a heat proof glass bowl and chill in an ice bath to see if it sets up or sets down....


Your Grandma took acid? That's a gal I'd like to know! :-)
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Dilbert



Joined: 19 Oct 2007
Posts: 1026
Location: central PA

PostPosted: Wed Jun 25, 2014 4:07 pm    Post subject: Reply with quote

nah. she would take a spoonful of the syrup and drizzle it into a glass of cold water.

similar to judging the 'thread' stage of sugar. I was too young to appreciate or ask "and 'zactly what are you looking for?" - so I know what she did but I lack the calibration....
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Jim Cooley



Joined: 09 Oct 2008
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Location: Seattle

PostPosted: Thu Jun 26, 2014 4:28 pm    Post subject: Reply with quote

Dilbert wrote:
I was too young to appreciate or ask "and 'zactly what are you looking for?" - so I know what she did but I lack the calibration....


Sheesh, don't we all know that feeling! I used to call my own Grandma, sometimes drunk as a skunk, and ask how to do something.

Shoulda, coulda, woulda written it all down.
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Dilbert



Joined: 19 Oct 2007
Posts: 1026
Location: central PA

PostPosted: Thu Jun 26, 2014 6:10 pm    Post subject: Reply with quote

>>shudda coudda...

I was a bit more fortunate in that regard. after my grandfather died she moved in with my parents - about a hour drive.

I'd go pick her up and she would stay with us for weekend/couple days.
the granny-plate special was usually fresh liver & onions - she&me, DW wouldn't go there.... but the kids were small enough they'd eat most anything if someone else was enjoying it - and they did.

then as teens they hated it; at 30+ they call me up to learn how to do that ... go figger.

my grandparents operated a hunting/fishing lodge for decades. he hunted / fished / gardened, she canned / preserved, cooked. she had a lot of recipes and specialties, most of them "pre-electricity" days..... buckwheat pancakes amongst them; I have her ceramic pitcher she kept her 'starter' in. with just the two of us, I have trouble keeping the (wild yeast) starter going, so it's become one of those rare treats-on-two-week-notice things.

so once upon a time I snagged her recipe boxes - she had three - and she & I went thru the 3x5 cards and I made notes. I did miss the cream corn casserole - an annual Thanksgiving side - and everyone loved it, especially me. I found four (slightly) different recipes, so it took a little time and experimenting to reproduce it. but I managed - well, it tastes like I remember it - I guess that's what counts.
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Jim Cooley



Joined: 09 Oct 2008
Posts: 346
Location: Seattle

PostPosted: Thu Jun 26, 2014 10:24 pm    Post subject: Reply with quote

Dilbert,

What a sweet story!

The granny plate special reminds me of my friend's mother's recipe for chopped liver. I had it sitting around for years (decades?), with amendments, and couldn't find it.

I wrote her son and got something equivalent, but it's not the same as them old 3 x 5 cards.

Jim
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Michael Chu



Joined: 10 May 2005
Posts: 1635
Location: Austin, TX (USA)

PostPosted: Fri Jun 27, 2014 7:03 pm    Post subject: Reply with quote

Unless you guys are making jellies and jams a whole different way than I do, you shouldn't be concerned about the sugar temperature. Jellies and jams are generally not cooked to the point / temperature where you'd be making candies (where sugar solution temperature makes the sugar form different crystal structures when cooled resulting in the various textures we call soft ball, hard crack, etc.). Jellies and jams is all about pectin.

In fact, if you work hard enough, you don't even have to add sugar to make a jam. This is especially plausible with fruits that are naturally high in pectin like apples and cranberries where simply the application of heat can break down enough of the cellulose and cell walls to release enough pectin to gel the liquid. In low pectin fruits like peaches and pears, this is extremely difficult without adding pectin somehow (through introducing apples is a traditional means - but these days it's just easier to add some pectin which has been extracted from fruit and dried and powdered). Extremely ripe fruit can also be a challenge as the ripening process breaks down pectin naturally, so a ripe apple will have less pectin than an unripe apple.

Why all the sugar? Sugar and acid assist pectin to bind with water to form a gel. Naturally, fruits have a lot of sugars and acids, so adding more might not be necessary, but adding more definitely helps form a gel easier. One problem with working with fruits is that each batch has a different amount of pectin, sugar, and acid in it (plus the variations from beginning of season to end of season and year to year). So it is very difficult to produce a consistent product without measuring pectin, sugar, and acid levels in the fruit base - something most home cooks won't be able to do. The solution is simply to add a known quantity of pectin, sugar, and acid to ensure that the mixture will gel. It is possible that if your batch of fruit has a lot of pectin, you'll end up with a firmer jelly or if your batch is low in pectin (or you are using a low pectin fruit), that your jelly could be runny. To correct this, simply increase or decrease the amount of additional pectin added to the recipe. The easiest way to do that is probably to chop up a bunch of fruit, mix it, and make a small scaled down batch to determine if it will be runny or firm and then cook the whole batch with an adjusted amount of pectin. Modern pectin binds very well and the use of additional sugar is not necessary if not desired. Some acid typically helps though.
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