1. the process of becoming sour or bitter

1. present participle of sour; becoming or making sour or bitter in taste
2. becoming unpleasant, unfriendly, or hostile

Examples

• The milk is souring in the heat.
• Their friendship has been souring over the past few months.
• The souring of the cream ruined the recipe.
• Relations between the two countries are souring rapidly.
• She noticed the souring smell coming from the refrigerator.
• The political climate is souring ahead of the election.
• The souring process takes several days in warm weather.