For a long time in the history of beer, beer has been cloudy and dark. The first clear yellow beer was created in 1842 in the Czech city of Plzeň. Nowadays, in order to restore the classics, some brewers often choose to ferment in bottles without filtration. 
For example, the Fendi Club832 IPA craft beer produced due to a special process is a cloudy beer, such as unfiltered or slightly filtered beer, which can even give an additional complex flavor.
There are four main reasons why craft beer is cloudy:
Yeast cloudy: Caused by wild yeast mixing or yeast re-fermentation, the main manifestation is that the wine loses its light, turbidity, and precipitation, and the bubbles are very sufficient after opening the lid, which is often accompanied by the phenomenon of foaming (beer gushing out from the mouth of the bottle), and there is a phenomenon of "smoking" at the mouth of the bottle when pouring wine into the glass. 
Turbid by the cold: When the beer is stored or transported for a certain period of time at about 0, because of the low temperature, some small suspended particles often appear in the liquor, which makes the beer lose its light. If it is stored at low temperatures for a longer period of time, large condensates will appear in the wine and cause precipitation. If the storage temperature rises to more than 10 when the beer is in the matte stage, the liquor will return to a transparent state. This cloudiness caused by exposure to cold is actually the condensation of proteins.
The starch is cloudy: Due to incomplete saccharification, there is still a certain amount of starch left in it, which causes turbidity, and gradually appears white precipitate.
Oxidative turbidity: When beer is bottled or keged, it inevitably comes into contact with oxygen in the air and causes turbidity, and the more air, the faster the turbidity. Therefore, the amount of beer should be reduced during storage, and it should be stored at a suitable temperature.
There are many reasons why craft beer is cloudy, including cooling, yeast, starch, and leaving it for too long or improper disposal, among others. These factors can cause the substances in craft beer to settle and cloudy, however, these cloudiness is not necessarily harmful to health. Therefore, before consuming a cloudy beer, it is best to know the reason for its cloudiness. If the cause cannot be determined, it is best not to drink it to avoid health effects.