Remove peaches, drain, and place in a bowl of ice water. Peel when cool enough to handle (ripe peaches will now peel easily)
Remove pit, and slice each peach into quarters, removing any bruised parts.
Mix in lemon juice to prevent oxidation, then add mixture along with sugar, salt, and vanilla extract to a large stock pot and heat over high flame until boiling.
Stir frequently and reduce heat if necessary to avoid burning; continue cooking for up to 12 minutes.
You can test the thickness by dropping a small amount of jam onto a cool dish (since jam will thicken after cooling)
Refrigerate for up to 2 months or can using information from pickyourown