When Qin Huai left Zheng Siyuan's house, he was carrying half a jar of crab yellow sauce made by Zheng Da.
According to Zheng Siyuan, it's unlikely that Qin Huai could have authentic double crab buns nowadays, so tasting some relatively authentic crab yellow sauce would suffice.
Zheng Da only makes a few jars of crab yellow sauce each year. The jar from Zheng Siyuan was snatched from Zheng Da by force. Half for research, half for Qin Huai to eat — a reasonable distribution.
Qin Huai cheerfully carried the half jar of crab yellow sauce home, forgetting to tell Zheng Siyuan that there were some snacks he brought on the entryway shelf.
This directly led to Zheng Siyuan simmering sauce in the kitchen until after 8 p.m., and only when he cleaned up the kitchen and walked to the entryway did he notice some additional items.
Two familiar snacks and one not-so-familiar one.
