Is it necessary to use ice or I can cool the mixture and put it in the fridge overnight?

Recipes call for an ice bath at the end of cooking a custard to avoid any egg bits from forming. The idea is to immediately put the bowl into an ice bath and continue to stir scraping the bottom to keep the custard from continuing to cook.

After a few minutes, you are supposed to put it in the coldest area of your refrigerator to get it to as close to freezing (without freezing) as possible. Most recipes recommend overnight. That ensures the ice cream maker solidifies the custard as soon as possible minimizing the ice crystal size and making a creamier ice cream.

I just chilled the mixture in the fridge and tucked a couple ice packs around it to make it cool more quickly. Keeping it in a bowl with a pouring spout also makes it a lot easier to pour into the ice cream maker than pouring it from a Ziploc bag (and it is easier to scrape on the bowl so you don't lose any of the custard).

We made the backyard mint recipe from her book this weekend...and I thought the ice bath idea was an extra step but I was hopeful that the outcome would be worth it and it was. It was so creamy...still today.

The theory behind overnight refrigeration is that the protein molecules relax and expand, becoming more fully hydrated, and therefore yielding a more silky consistency when spun.

I agree with amysarah; leaving it in the refrigerator until cold takes more time, but will turn out the same as with a quick-chill method. And wait until you try this ice cream -- it ROCKS!!!

I've haven't made this particular recipe yet - love lemon ice cream, so I definitely will - but I frequently make ice cream custard/base the day before (or early that morning,) and chill it overnight in the fridge.

The quick-chill ice bath method is great when you need to speed the process, but I find a slower overnight/multi-hour chilling sometimes actually improves the flavor - gives it a chance to develop and meld.