Lead Conductance Value

The Lead Conductance Value (LCV) (also known as Conductometric Value or CV) is a widely utilised measurement used to estimate the α-acid concentration and also bittering potential of recently harvested hops.

The Lead Conductance Value is measured by extracting the α-acids from the hops with methanol and then titrating a solution of lead acetate, methanol and some acetic acid into the α-acid / methanol solution. The α-acids and lead form a bright yellow lead salt precipitate that is insoluble in methanol. During the titration the conductance of the titrated solution is measured. The conductance of the solution remains relatively stable until all the α-acids are bonded with the added lead, this is the end point or lead conductance value. After the end point has been reached the lead in the solution that does not bond with α-acids causes the conductance of the solution to rise in a linear manner. If the conductance of the titration is graphed then the result is two linear lines and a small curve around the end point. The true end, and therefore true lead conductance value, can be determined by extrapolating the linear lines and finding the point at which they intercept.

Synonym: Conductometric Value , CV