Rules of jelly thumb?

[bunn]

Yesterday we had lamb chops, and lacking anything interesting to dress them with, I made a lemon and mint jelly.

I took two lemons, zested and squeezed them, added some water and some sugar and boiled for a bit. Then I tasted and it seemed a bit tart so I put some more sugar in. Finally I added piles of chopped mint and boiled a bit more.  At that point it set if I dripped it onto a cold plate, so I strained out the mint and zest and stuck it in the fridge to congeal.  It was good.

Thing is though, I have no idea if I could have made a larger quantity of less acidic jelly if I'd put more water in, or if it would then just have been a syrup.  Or if I could have got away with one lemon.  I have a vague feeling that this has something to do with the pectin content of the lemons, but how one estimates that, I do not know.

Does anyone know about the theory behind jam and jelly recipes?   I'm OK with making stuff from a recipe, or even improvising based on a recipe -  but would like to know more about how the gelling bit works so I can be more freeform about my jellies in future!  Google is not being helpful today: it gives me recipes, not an understanding of the principles behind them.

Comments

[adaese.livejournal.com]

Citrus fruit pips are very rich in pectin, which is why when making marmalade you stick the pips and pulp in a muslin bag and boil them up together with the juice and rind. (The bag is so you can get them out again, it doesn't add anything to the flavour).

My grandmother used to make mint jelly with a base of apples, which are also very rich in pectin. This would probably mean you could dispense with a lot of water & sugar. At a guess, something like "boil apples to a pulp with a bit of sugar, lemon juice, and the pips or perhaps all the rest of the lemon in a little bag". But as I've only one apple in the house, I'll leave you to do the experimenting.

[bunn.livejournal.com]

Wrong time of year for apples at the mo, but I often make bramble jelly on a base of apples in the autumn, and yes, that it pretty much how it goes: that was what I based the lemon jelly on. You do need some sugar to make it palatable though (or I think so anyway), the greener apples are the more pectin-y ones so otherwise it ends up very sharp.

I just left the pips in when squeezing the lemons, as I put it all through a sieve at the end anyway.