solder ID

[danmat]

I have quite a few rolls of solder gathered up thru the years via estate, garage sales.
Most don't have labels, is there an easy to tell if its rosin or acid core, some is really small diameter. I know the rosin core smokes a lot when using,does the acid core do the same?
Thanks Dan

[William Yanda]

Not being smart, but rosin core has a piney smell, acid core not so much.