Hi, I’ve just acquired a second hand wort chiller. It looked clean so I gave it a good rinse under hot water before using it today. After my brew I was rinsing it off and noticed a couple of small (1/2 inch by 1/8 inch) patches of green oxidization. I didn’t pick up on these in my initial inspection. I know that this stuff is undesirable. Should I throw my batch out or is it safe to drink?