def mcu(pounds: float, lovibond: float, gallons: float) ->float:
    """
    Determines Malt Color Unit (MCU).

    Parameters
    ----------
    pounds : float
        Weight in pounds.
    lovibond : float
        Color of malt in degrees lovibond.
    gallons : float
        Water volume in gallons.

    Returns
    -------
    float or None
        Malt Color Unit.
    """
    if gallons != 0:
        return pounds * lovibond / gallons
    else:
        return
