CA Food & Agric Code Section 62201

(a)

If a handler does not pay for market milk delivered to him or her at the time and in the manner specified in the contract, the handler shall pay the producer interest on the unpaid amount from the time the payment was due until paid at the rate of 12 percent per annum. This interest is in addition to any other penalties provided in this chapter.

(b)

If there is no contract for the delivery of milk to the handler or the delivery was made as a single transaction between the producer or handler, the handler shall pay the department interest on the unpaid amount from the time the payment was due until paid at the interest rate specified in subdivision (a). The interest is in addition to any other penalties provided in this chapter.