Cure begins working the minute you mix it in the meat(stopping bacteria growth). It takes 24 hours to take full effect unless you add citric acid. As long as the cure is done by the time you put the finished product in the ice bath you are good to go. Do not use non encapsulated acid in your mix! You will not be happy. It changes the Protein extraction and makes the sausage crumbly, may cause fat out and affects the absorption of smoke. I use ECA to give summer sausage more tang and since I have the time let it sit overnight in the cooler, add the ECA in the morning, stuff and smoke.