Anyone used Certo for jam making?

[Ham]

Made some Courgette (OK, marrow by size) and Ginger jam today, and I used Certo for the first time (coz it was all there was in the not-so-supermarket). The jam contained just sub 2Kg of courgette, with 4 lemons juiced for added liquid and 2Kg sugar. Brought the mix up to 104^o and as the bottle told me took the pan off the light and stirred it in. No messing about boiling after it was added (!!)

Only it doesn't look like it is going to set flavour is great, though.

[hellymedic]

Suspect there's too much water/not enough boiling in the mix.
Though I usually used jam sugar rather than Certo (though I do have an ancient bottle of Certo in the fridge), I boiled longer and hotter (I think).

I stopped using my jam thermometer when I started using the microwave for making jam.

Usual jam recipe is equal weights jam sugar and fruit, Microwave on full till jammy, stirring occasionally and making sure mix doesn't boil over.

[T42]

50/50 sugar:fruit was my mum's recipe too, but you don't really need the sugar - plenty of bought jam here is 100% fruit, although not all the fruit will be the one on the label.

Academic for me, though.  Last time I ate jam was at breakfast on a 400k in 2013.

[MikeFromLFE]

50/50 sugar:fruit was my mum's recipe too, but you don't really need the sugar - plenty of bought jam here is 100% fruit, although not all the fruit will be the one on the label.

Academic for me, though.  Last time I ate jam was at breakfast on a 400k in 2013.

Mrs M has been making 100% fruit jam over the last couple of years with the fruit from our allotment and it keeps very well. (she tells me it's got no added sugar, but I do know she sometimes lies to me)
Could the freshness of the ingredient(s) be a factor in setting?

[hellymedic]

As I understand it, jam sets when the sugar content is high enough (and is minimally caramelised) in a suitably low pH (that's why lemon juice) and setting is assisted by pectin.
Apples, Certo and jam sugar contain lots of pectin.
Strawberries have very little, plums have a bit more, etc.

I think there's more pectin in fruit that's less ripe but I'm not sure.

104C is a bit low as a boiling point for jam to set and indicates a high water/low sugar concentration.

[T42]

I'd need to ask the expert, i.e. the missus, but with 100% fruit you get double the amount of pectin wrt the 50/50 recipe, so unless you're using fruit that's low in pectin you wouldn't need additives.

https://en.wikipedia.org/wiki/Pectin

[hellymedic]

That's still a LOT of water!

[Ham]

FTR, I know haz jam. Added a packet of pectin, boiled until skinning, job done. Don't think I'll go down that Certo hole again.