Can I heat the cold brew?Updated a day ago

Yes. You can heat it up and it will still be one of the smoothest cups of coffee you have ever had. For a true hot coffee connoisseur, they will note a difference (less acidity, less bitterness) than a hot cup because this is, well, heated cold brew which is chemically different. You can absolutely heat in the microwave as long as you ensure you don't overheat/boil the coffee. The best method is to heat on the stovetop under low heat.