ChatterBank3 mins ago
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The object of a teabag is to allow water in to extract flavour from the tea. This depends on the surface area available to let the water in. The worst possible shape for a teabag, would be a sphere, since this has the minimum surface area for a given volume. The tetrahedral shape of "pyramid" teabags is a fairly close approximation to a sphere, so is not really a good idea. The good old flat teabag design is far more effective.