"Kathi Jones" wrote in message
...
(clipped)
I'm not sure about the baking soda, but I think it has something to do
with foaming? Just a guess.

Kathi

One of these days, I'll make the lime marmalade I'm looking for. In the
meantime, the baking soda is to reduce the pH. Seville oranges are pretty
sour, no? One website I ran across mentioned that they thought jams,etc.,
set best at about 3.2pH. Limes are generally about 0, and lemons about 1-2.
That said, very ripe fruits will probably be higher in pH. And of course
with so many hybrids, there is no real average anymore.
My 2c worth.
Edrena