_Humulus vel Lupulus_; _Hops_; F. _Houblon_; G. _Hopfen_.
=Botanical Origin=—_Humulus Lupulus_ L.,—a diœcious perennial plant,
producing long annual twining stems which climb freely over trees
and bushes. It is found wild, especially in thickets on the banks
of rivers, throughout all Europe, from Spain, Sicily and Greece to
Scandinavia; and extends also to the Caucasus, the South Caspian
region, and through Central and Southern Siberia to the Altai
mountains. It has been introduced into North America, Brazil (Rio
Grande do Sul), and Australia.
=History=—Hops have been used from a remote period in the brewing of
beer, of which they are now regarded as an indispensable ingredient.
Hop gardens, under the name _humularia_ or _humuleta_, are mentioned
as existing in France and Germany in the 8th and 9th centuries; and
Bohemian and Bavarian hops have been known as an esteemed kind since
the 11th century. A grant alleged to have been made by William the
Conqueror in 1069, of hops and hop-lands in the county of Salop,[2047]
would indicate, were it free from doubt, a very early cultivation of
the hop in England.
As to the use made of hops in these early times, it would appear that
they were regarded in somewhat of a medicinal aspect. In the _Herbarium
of Apuleius_,[2048] an English manuscript written about A.D. 1050, it
is said of the hop (_hymele_) that its good qualities are such that men
put it in their usual drinks; and St. Hildegard,[2049] a century later,
states that the hop (_hoppho_) is added to beverages, partly for its
wholesome bitterness, and partly because it makes them keep.
Hops for brewing were among the produce which the tenants of the abbey
of St. Germain in Paris[2050] had to furnish to the monastery in the
beginning of the 9th century; yet in the middle of the 14th century,
beer without such addition was still brewed in Paris.
[2047] Blount, _Tenures of Land and Customs of Manors_, edited by
Hazlitt, 1874. 165.
[2048] _Leechdoms, Wortcunning and Starcraft of Early England_, edited
by Cockayne, i. (1864) 173; ii. (1865) ix.
[2049] _Opera Omnia_, accurante J. P. Migne, Paris, 1855. 1153.
[2050] Guérard, _Polyptique de l’abbé Irminon_, i. (1844) 714. 896.
The brewsters, bakers and millers of London were the subject of a
mandate of Edward I. in A.D. 1298; but there is no reason for inferring
that the manufacture of malt liquor at this period involved the use of
hops. It is plain indeed that somewhat later, hops were _not_ generally
used, for in the 4th year of Henry VI. (1425-26), an information was
laid against a person for putting into beer “an unwholesome weed called
_an hopp_;”[2051] and in the same reign, Parliament was petitioned
against “that wicked weed called _hops_.”
But it is evident that hops were soon found to possess good qualities,
and that though their use was denounced, it was not suppressed. Thus
in the regulations for the household of Henry VIII. (1530-31), there
is an injunction that the brewer is “not to put any hops or brimstone
into the ale”;[2052] while in the very same year (1530), hundreds of
pounds of Flemish hops were purchased for the use of the noble family
of L’Estranges of Hunstanton.[2053]
In 1552 the cultivation of hops in England was distinctly sanctioned by
the 5th and 6th of Edward VI. c. 5, which directs that land formerly in
tillage should again be so cultivated, excepting it should have been
set with _hops_ or saffron. Notwithstanding these facts, hops were
for a long period hardly regarded an essential in brewing, as may be
gathered from the remark of Gerarde (_ob._ A.D. 1607), who speaks of
them as used “to season” beer or ale, explaining that notwithstanding
their manifold virtues, they “rather make it a physical drinke to
keepe the body in health, than an ordinary drinke for the quenching of
our thirst.” In reality, other herbs were for a long period employed
to impart to malt liquor a bitter or aromatic taste, as Ground Ivy
(_Nepeta Glechoma_ Benth.); anciently called Ale-hoof or Gill; Alecost
(_Balsamita vulgaris_ L.); Sweet Gale (_Myrica Gale_ L.); and Sage
(_Salvia officinalis_ L.). Even Long Pepper and Bay Berries were used
for the same purpose,[2054] but in addition to hops.
Though English hops were esteemed superior to foreign, and were
extensively grown as early as 1603, as shown by an act of James
I.,[2055] Flemish hops continued to be imported in considerable
quantities down to 1693.
[2051] The authority for this statement is an isolated memorandum in
a MS. volume (No. 980) by Thomas Gybbons, preserved in the Harleian
collection in the British Museum.
[2052] _Archæologia_, iii. (1786) 157.
[2053] _Ibid._ xxv. (1834) 505.
[2054] Holinshed, _Chronicles_, vol. i. book 2. cap. 6.
[2055] 1 James I. (anno 1603) cap. 18.
=Structure=—The inflorescence of the male plant constitutes a large
panicle; that of the female is less conspicuous, consisting of stalked
catkins which by their growth develope large leafy imbricating bracts,
ultimately forming an ovoid cone or strobile, which is the officinal
part. This catkin consists of a short central zigzag stalk, bearing
overlapping rudimentary leaflets, each represented by a pair of
stipules. Between them are 4 female florets, each supported by a bract.
After flowering, the stipules as well as the bracts are much enlarged,
and then form the persistent, yellowish-green, pendulous strobile. At
maturity, each bract infolds at its base a small lenticular closed
fruit or nut, ⅒ of an inch in diameter. The nut is surrounded by a
membranous, one-leafed perigone, and contains within its fragile, brown
shell an exalbuminous seed. These fruits, as well as the axis and the
base of all the leaf-like organs, are beset with numerous shining,
translucent glands, to which the aromatic smell and taste of hops are
due.
=Description=—Hops as found in commerce consist entirely of the fully
developed strobiles or cones, more or less compressed. They have a
greenish yellow colour, an agreeable and peculiar aroma, and a bitter
aromatic burning taste. When rubbed in the hand they feel clammy, and
emit a more powerful odour. By keeping, hops lose their greenish colour
and become brown, at the same time acquiring an unpleasant odour, by
reason of the formation of a little valerianic acid. Exposure to the
vapour of sulphurous acid retards or prevents this alteration. For
medicinal use, hops smelling of sulphurous acid should be avoided,
though in reality the acid speedily becomes innocuous. Liebig has
refuted the objections raised by brewers to the sulphuring of hops.
=Chemical Composition=—Besides the constituents of the glands
which are described in the next article, hops contain according to
Etti’s elaborate investigations (1876, 1878) _humulotannic acid_
and _phlobaphene_. The former is a whitish amorphous mass, soluble
in alcohol, hot water or acetic ether, not in ether. By heating the
humulotannic acid at 130° C., or by boiling its aqueous or alcoholic
solutions, it gives off water, and is transformed into phlobaphene, a
dark red amorphous substance,
(C₂₅H₂₄O₁₃)₂ = OH₂ · C₅₀H₄₆O₂₅.
humulotannic phlobaphene.
acid.
The latter substance, on boiling it with dilute mineral acids, again
loses water and furnishes glucose.
From raw phlobaphene ether removes the _bitter principles_ of hops,
a colourless crystallizable and a brown amorphous resin, besides
chlorophyll and essential oil.
By distilling hops with water, 0·9 per cent. of _essential oil_ are
obtained. Personne (1854) stated it to contain _Valerol_,[2056] C₆H₁₀O,
which passes into valerianic acid; the latter in fact occurs in the
glands, yet according to Méhu[2057] only to the extent of 0·1 to
0·17 per cent. When distilled from the fresh strobiles the oil has a
greenish colour, but a reddish-brown when old hops have been employed.
We find it to be devoid of rotatory power, neutral to litmus paper, and
not striking any remarkable coloration with concentrated sulphuric acid.
Griessmayer (1874) has shown that hops contain _Trimethylamine_, and
in small proportion a liquid volatile alkaloid not yet analysed, which
he terms _Lupuline_. The latter is stated to have the odour of conine,
and to assume a violet hue when treated with chromate of potassium and
sulphuric acid.
Lastly, Etti also found arabic (pectic) acid, phosphates, nitrates,
malates, citrates, and also sulphates, chiefly of potassium, to occur
in hops. The amount of ash afforded by hops dried at 100° C. would
appear to be on an average about 6-7 per cent.
=Production and Commerce=—England was estimated as having in 1873,
63,276 acres under hops. The chief district for the cultivation is the
county of Kent, where in that year 39,040 acres were devoted to this
plant. Hops are grown to a much smaller extent in Sussex, and in still
diminished quantity in Herefordshire, Hampshire, Worcestershire and
Surrey. The other counties of England and the principality of Wales
produce but a trifling amount, and Scotland none at all.
In continental Europe, hops are most largely produced in Bavaria and
Württemberg, Belgium and France, but in each on a smaller scale than in
England. France in 1872 is stated to have 9223 acres under hops.[2058]
[2056] A substance with which we are not acquainted.
[2057] _Thèse_, Montpellier, 1867.
[2058] _Agricultural Returns of Great Britain_, &c., 1873, presented to
Parliament, 48. 49. 70. 71.
Notwithstanding the extensive production of hops in England, there is
a large importation from other countries. The importation in 1872 was
135,965 cwt., valued at £679,276: of this quantity, Belgium supplied
66,630 cwt., Germany 36,612 cwt., Holland 16,675 cwt., the United
States 10,414 cwt., France 5,328 cwt. During the same period hops were
exported from the United Kingdom to the extent of 31,215 cwt.[2059]
=Uses=—Hops are administered medicinally as a tonic and sedative,
chiefly in the form of tincture, infusion or extract.