[hamstergbert]

It has always narked me that there is usually a cupfull or so sugar scum to skim off when making jam and jelly.  For a change today while doing some Rowan and Crabble, gave the gunge a two minute nuking in the microwave.  I rather think that has done the trick, quite chuffed with the outcome! 

No doubt everyone else has known this trick for years!

[PAULW]

I chuck in a knob of butter this get rid of the scum.

[mumofstig]

same here 

[arugula]

I've known the trick for years.

[hamstergbert]

I do chuck in a knob of butter - after skimming off as much of the sugar scum as I can be bothered with (and even at that it doesn't seem to get rid of ALL the remaining fragments).
Presumably I am doing something wrong that will make all the jam and jilly boffins out there roll their eyes contemptuously and come out with mutterings along the lines of "What a thicko, clearly doesn't even know about {insert obviously overlooked technique here}!  Phew, a right old bonehead.   Duh or what!"

gi's a kloo, fer the love of the wee man....

[Trillium]

I'm a skimmer, pure and simple. I take the pot off the burner, leave it for about 2 minutes and the scum gathers in a nice firm lump which I then take off with a skimmer. Almost every speck comes off. My mum does the butter trick and I don't like her jams at all because of the butter.

[willowman]

I know this sounds a daft question (like most of mine), but how big is "a knob of butter"?
As I have been making bread I now know roughly how much is an ounce or half an ounce, so can somebody give me an approximate weight of the amount of butter to use.
I do understand it may depend on the quantity of jam being made.

[Trillium]

I'd say roughly 2 tbsp, maybe 3 tbsp, depending on the quantity you're working with.

[mumofstig]

I add about the same amount that you get individually wrapped in a cafe, for each maslin panful