is a German
name for products, especially chemical compounds and provisions developed in wartimes when shortage of certain goods was imminent. It is associated with cheap replacement, low quality and disgust. The word surfaced during World War I
because the allied fleet cut off all transport to Germany by sea.
Ersatz products that were developed were, for example: synthetic rubber (buna produced from oil), benzene for heating oil (coal gas) and coffee, using roasted beans, which were not coffee beans.
Also countries that were indirectly affected by the blockade developed ersatz products, for example in Sweden during World War II. Here a certain kind of gas produced from boiling wood (gengas) was used as ersatz for gasoline.