Why do Moccamaster thermal carafes come with two lids?

Moccamaster thermal carafes include two lids designed for different uses:

• Brew-Thru Lid: Use this lid while brewing. Coffee flows directly through it into the carafe, helping minimize heat loss. Coffee can also be poured without removing the lid.
• Travel Lid: Use this lid when you want to retain heat for a longer period or transport the carafe. To pour, loosen the lid approximately one-quarter to one-half turn. Retighten it after pouring.