Coffee factories
At the Ijen Plateau one can find 2 coffee factories, namely Blawan and Sempol. The coffee factory at Blawan is already producing when the daily harvest is not yet abundant, while the factory at Sempol starts running as yields increase.

Water is most important to a coffee factory
The location of the Blawan coffee factory was carefully chosen by the Dutch. The nearby water source is the main reason. In the dry period the supply of water is surprisingly bigger than during the raining season. Water is used for almost every process in the coffee factory, among which you will find the transport of the coffee beans from the assembly to the first process of peeling the beans. Just before peeling, low quality beans get separated, because less quality coffee beans sink to the bottom of the water tank. Although water is important in the process, the final goal is to dry the beans up to 11% water only.
Tour coffee factory Blawan and Sempol
In both coffee factories, Blawan and Sempol, you can get a guided tour of approximately two hours. The price for a tour in Sempol can include a plantation tour (IDR 50,000). Ask at the reception of Arabica Homestay. A coffee tour in Blawan costs about IDR 40,000 per person. Note: as locals in Sempol and Blawan can't speak English, it is not such a guided and/or explanatory tour. If you speak a bit bahasa, the tour might be more convenient. You could ask one of the hotel staff whether he is available to guide.
The coffee factory should always be visited after 3 pm, as the factory has to wait for the power to turn on.