Company Names, addresses, dates:¹

  Listed under breweries:
    John Kozel, 572 L North (1858,1860) [was also his home address]
    John Kozel, 592 L North (1862)
    John Kozel, rear N Cap bet N and O north (1864)
    John Kozel, N north n North Capitol (1865-1866)
    John Kozel, N bet 1st and N Cap (1867)
    John Kozel, 43 N nw (1870, 1877-1879, 1881)
    John Kozel, 43 H nw (1874) [presumably a mis-print and should be N street]
    George Kozel, 1105 7th NW (1880)
    George Kozel, 43 N NW (1880-1881)
    Leo Ewald, 43 N NW (1882)
    John Eller, 43 N NW (1883-1890) [Listed under bottlers, not brewers]

  Listed under saloons and restaurants:
    George F. Kozel, 1813 14th NW (1882-1887)
    George F. Kozel, 1827 14th NW (1888-1896,1899-1904)
    George F. Kozel, 1829 14th NW (1897-1898)

Notes:
John Kozel's obituary said that he came to Washington DC in 1854, and started a brewery that same year on 9th Street near M street NW ².
From the city directories, it appears that George Kozel took over John's brewery for 2 years, then sold it to Leo Ewald, who then sold it to John Eller. After George gave up the brewery, he ran a beer garden until at least 1904.
For more information about Kozel, see this web site.

Bottles:

book # (64 in the stoneware section) This is a 7" tan stoneware beer bottle. It has the following imprinted on the shoulder: imprinted on shoulder: JOHN KOZEL