Yes! Mason jars are a great alternative to storing food in plastic containers. When freezing food like this marinara sauce in jars, make sure to avoid sudden temperature changes that could crack the glass. This means, allow the food to cool slightly before filling the jars. Only fill them 3/4's of the way full to allow for expansion as they freeze. Cool the jars completely overnight in the fridge before transferring them to the freezer. Thaw overnight in the fridge to use.