What will influence the higher alcohols in beer?

The higher alcohols is one of the mainly by-product during beer fermentation. Generally the higher alcohols in good light beer should better within 50-90mg/L. It is also the main element that will cause headache.

So what will influence the higher alcohols in beer? Today we will do some clarifications as below:
1.The yeast strains
The powder yeast with higher alcohols at 69-90mg/L, Flocculent yeast at 22-49mg/L, High fermentable yeast with the most highest level of higher alcohol. The brewmaster should choose the suitable yeast strains during brewing.
2.The wort components
The wort contents of enough αamino nitrogen and fermentable carbohydrate, that will form less higher alcohol after synthesis. But if adopted too much adjunct or added too much sugar, the higher alcohol in beer will be increased as the αanimo nitrogen was reduced.
3.How much yeast added
The most suitable one is (1.5~1.8)x107PC/ml. A higher inoculum size will reduce the formation of higher alcohol.
4.Fermentation temperature
A higher content of oxygen in wort and a higher fermentation temperature will helpful for the yeast propagation. Which will reduce the formation of higher alcohol.
5.Fermentation method

The unitank fermentation will cause a higher content of higher alcohol in beer. Generally will increase 20-25%
.