Turns out, using instant coffee powder in a drip machine can lead to bigger problems than uneven taste. It may even lead to machine clogging!
Ever run out of ground coffee or beans in the morning and have to settle for some instant coffee? It may not sound like a problem but if you use a drip maker it could become a problem in a heartbeat. While making instant coffee manually, i.e., the pot and pan way is perfectly fine, putting it through a machine is not advisable, especially a drip one.
Chances are the instant coffee may not dissolve properly, leading to clogs and uneven extraction. It is important to note that instant coffee is made from brewed coffee that has been freeze-dried or spray-dried to remove the water content. This dry powder can be rehydrated with hot water to produce a cup of coffee and it dissolves quickly.
However, a drip coffee maker is designed to handle ground coffee only. Much like a pour-over, drip coffee is made by pouring hot water over coffee grounds. The coffee drips into the pot below as it brews and hot water passes through ground beans to brew it. When applied to instant coffee, this technique could result in an uneven dispersal of water through the coffee.
Moreover, you could be messing up your brewer since it could have residues of dried instant coffee chunks and its taste may still linger the next time you use fresh coffee grounds in the machine. One way to use instant coffee in a machine is to place instant coffee in the machine's glass carafe rather than the filter basket, so you have less cleaning up to do later on.
What About A French press, A Moka Pot, A Keurig, Or a Pod Machine?
The short answer is no! A French press coffee maker is designed for coarsely ground coffee beans, so the extraction process and mesh filter are not at all unsuitable for dissolving instant coffee granules. A moka pot uses a funnel chamber to infuse natural coffee grounds; although you can technically use instant coffee powder in the equipment it is quite futile since instant coffee is not designed for extraction of any kind.
A pod system simply has no slot for instant coffee and is used for brewing pre-packaged coffee. A Keurig machine can be used for making instant coffee, provided you have the correct K-Cup filter, which allows the fine particles of instant coffee to pass through efficiently. In case you don't, use a cupcake liner as a DIY K-Cup. The K-Cup is a sealed package which contains real and ground coffee and a paper filter. The coffee is brewed the same way, irrespective of the kind of coffee you're using.