Quoting Viv, Ev & Gwen ♥:" <blockquote><b>Quoting Trixie7678:</b>" Its like conter intuitive though. So the hopps ... [snip!] ... to the point where it would decrease your supply after two beers. Which is all you need to get the boost from the dark hops."
Thomas W. Hale, R.Ph. Ph.D., member of the LLLI Health Advisory Council, says this in his book Medications and Mothers' Milk (12th ed.):
Significant amounts of alcohol are secreted into breastmilk although it is not considered harmful to the infant if the amount and duration are limited. The absolute amount of alcohol transferred into milk is generally low. Beer, but not ethanol, has been reported in a number of studies to stimulate prolactin levels and breastmilk production (1, 2, 3). Thus it is presumed that the polysaccharide from barley may be the prolactin-stimulating component of beer (4). Non-alcoholic beer is equally effective.
In a study of twelve breastfeeding mothers who ingested 0.3 g/kg of ethanol in orange juice (equivalent to 1 can of beer for the average-sized woman), the mean maximum concentration of ethanol in milk was 320 mg/L (5). This report suggests a 23% reduction (156 to 120 mL) in breastmilk production following ingestion of beer and an increase in milk odor as a function of ethanol content.
Here is a study that suggests 23% decrease from consuming the equivilent of one beer.