answer:”.... any salmonella that makes it into peanut butter is more likely the result of an inadequate cooking process or contamination after roasting.” ”...peanut butter does make a good vessel for salmonella if it is introduced at some stage of manufacture. Although there’s not enough water in peanut butter to allow salmonella to grow, individual bacteria can live for months, or even years, trapped in the peanut oil.” Source Just like all other bacteria arrive in scratches, wounds and tempting foods…the bacteria float down on teeny, tiny parachutes.