Yield refers to the quantity of grapes that are produced per hectare vineyard. This harvest yield is expressed in hectoliters of must per hectare. In some wine regions or appellations, a maximum yield has been agreed to guarantee wine quality. In general, a lower yield – so fewer bunches per grapevine – gives more concentrated grapes and therefore a better quality wine. However, there is a limit to this and an extremely low yield can be detrimental for the wine quality. For example, because grapes swell too much due to an excess in nutrients and water, which results in compact bunches, bursted grapes and the development of fungi such as botrytis.