jmm1951 wrote:
> On Mar 23, 5:14 am, "FarmI" <ask@itshall be given> wrote:
>
>>"jmm1951" > wrote in message
>>
groups.com...
>>
>>
>>
>>
>>>On Mar 21, 7:10 pm, "FarmI" <ask@itshall be given> wrote:
>>>
>>>>"jmm1951" > wrote in message
>>>>
>>>>>I likeblackberrypreserves on toast for breakfast, but I'm not
>>>>>terribly keen on the high fructose corn syrup, so yesterday I decided
>>>>>to make someblackberrypreserves/jamat home for the first time. My
>>>>>previous experience was limited to making grapefruit marmelade without
>>>>>pectin, adding in a couple of lemons, then cooking until 218 degrees.
>>
>>>>>My marmelades have always set nicely, no problem.
>>
>>>>>Yesterday I looked up a recipe on the Internet forblackberry
>>>>>preserves.
>>
>>>>>It said equal weight of fruit and sugar, a bit of lemon juice, simmer
>>>>>for an hour, mix in 1 sachet of pectin, and away you go. This sounded
>>>>>nice and simple so I got 2 lbs of frozen blackberries and made the
>>>>>preserves.
>>
>>>>>However, I find today that it is not completely set. It is very nice,
>>>>>but it runs a bit more than I would like.
>>
>>>>>I also made grapefruit marmelade yesterday in a slightly larger
>>>>>quantity. I found that my candy thermometer was broken but boiled it
>>>>>down until it looked right, then threw in a sachet of pectin for good
>>>>>luck. The marmelade came out perfect. Positively orgasmic.
>>
>>>>>So why is theblackberryjamless set? I followed the recipe exactly.
>>
>>>>>The recipe seemed to suggest that if you used pectin there was no need
>>>>>to cook to 218 degrees. Or is it because I used frozen blackberries
>>>>>and not fresh? Or do I need more pectin? As pectin is rather
>>>>>expensive, this would definitely add to the cost of a batch.
>>
>>>>>Of course thejamis perfectly good, as long as you don't mind it
>>>>>running a bit, but I would like to know for next time.
>>
>>>>I've never used pectin in any of the various jams I make so I can't help
>>>>you
>>>>as to its effectiveness, I've also never used corn syrup (just sugar) and
>>>>nor have I ever taken the temperature of thejamas I make it as I use the
>>>>look and the feel and the 'cold saucer' treatment to see if it's reached
>>>>setting point. However, I can make good prize winningjamand have the
>>>>following comments which may or may not help.
>>
>>>>Set is helped by the addition of lemon juice, citric acid or tartaric
>>>>acid
>>>>which is why you have no trouble with achieving a set when you make
>>>>marmalade - lots of acid. Blackberries in common with strawberries are
>>>>low
>>>>in acid content so that is why the recipe mentioned adding lemon juice -
>>>>I'd
>>>>add more or some citric acid rather than more pectin.
>>
>>>>I coulnd't recall off the top of my head what sort of pectin levels
>>>>blackberries had so did a google and this site says all that I had
>>>>planned
>>>>to say so there is no point in my saying any
>>>>mohttp://www.abc.net.au/tasmania/stories/s1349335.htm
>>
>>>Yes, that Web site is helpful.
>>
>>>Anyhow, I decided to do the following:
>>
>>>Reheat thejam, add one pureed lemon to the mix, and boil it down to
>>>remove water and thus increase the percentage of sugar. As it tasted
>>>rather sweet, I also figured that adding the lemon would add a bit of
>>>sharpness to the flavor.
>>
>>>This worked quite well and thejamis now firmly set. However 2 lbs of
>>>blackberries and 2 lbs of sugar has now given me about 3 lbs ofjam.
>>
>>>I did a little bit more research, and the equation is quite complex,
>>>but basically with blackberries you need about 65% sugar and a certain
>>>degree of acidity to get a set. This proportion varies somewhat from
>>>fruit to fruit.
>>
>>>The math is not quite as simple as it seems, because to know the
>>>percentage of sugar, you will need to know the percentage of sugar in
>>>the original fruit, and to know the acidity you will need to know the
>>>original ph of the fruit, both of which may vary according to the
>>>ripeness of the fruit.
>>
>>>However, if we are not involved in industrial production, we can use
>>>empirical methods and get good results without getting into a lot of
>>>theory.
>>
>>>Next time I will do better.
>>
>>:-)) But you got a result so be pleased with yourself. I hope you don't
>>have so much troulbe next time :-))
>>
>>
>
>
> I am, I am. Now I am eating a jam that is every bit the jam equivalent
> of caviar for breakfast, and will probably never buy the factory-made
> stuff again.
>
> Half the point of newsgroups is that someone can look at these posts
> years in the future and avoid the mistakes I made.
>
I certainly hope not. I enjoy my jam and jelly mistakes over waffles in
the morning. <VBG>

George