Chapter IV The Substance Gruit

De Middeleeuwse Brouwerij en de Gruit - The Medieval Brewery and the Gruit.
by G. Doorman, 1955. Translated by Susan Verberg, 2017.
- specific translations or remarks by translator are within [square brackets].

Chapter IV The substance gruit.

Of what gruit was made here in this country, is best shown by the Cameraers-receipts of Deventer (Cam), and the city receipts of Wesel (Kra). As mentioned in the year 1339, the Bishop of Utrecht leased the gruitrecht of Deventer to that city and thus for the years 1339-1348 we have access to detailed accounts, from which I used the bulk information in the table of Appendix IV.
    For the contents of the gruit substance the account of 1339 is of most importance, because then gruit as a business was still pure, while after 1340 also 'medulla brasii' was sold, the nature of which I will explain in the next chapter.
    The raw materials bought for gruit ('ad fermentum') in 1339 include a large amount of mirtus and also some duris specibus and resina. At that time no grain or malt was bought.
    We also have information regarding the gruit in Wesel. Kraus mentions  (p. 57 and 79) bog myrtle as the main ingredient, which in the Latin text is indicated with 'custum'; this herb was sourced mostly from Deventer, Zwolle, Dordrecht and Arnhem. Also added were some laurel berries, falscher Enzian (= Siler montanum) [Laserpitium siler L. or laserwort] and also some resin.
    The following ingredients for gruit are often mentioned:

Mirtus = Myrica gale L. = gagel = custus (Fig. 2) [US: bog myrtle]

This heather- and swamp plant of North and West Europe, including Scandinavia and Great Britain, is known by many folk names including Brabantse Myrte, Osk, Myrtenheide [myrtle heather], costus (Schu 119), post, possem, Drentse thee [tea], luiskruid [lice herb], vlooienkruid [flea herb] (according to Heukels' pocket flora); gale, sweetgale, bog myrtle, dutch myrtle, sweet willow; gale odorant. As well as an herb for beer is it also used against infection and to exterminate pests.
    'Circa instans', a pharmaceutical-botanical work of the late 11th century called 'Mirtus seu mirta': 'frigida... in primo gradu, sicca in secundo' and 'Herbarijs' of circa 1350 (codex 15624-41 of K.B. Brussel) thus also says: 'Mirtus of mirta dats gagel, ende es cout in den iersten graet ende droge in den 2,' or, Mirtus or mirta is bog myrtle, which is cold in the first degree and dry in the second. It mentions the juice is good in syrups, but does not mention beer.
    The 'Book of Brother Thomas', an HS of 1328 at the U.B. of Utrecht, describes the preparation of oil out of myrtle in folio 34, and about bog myrtle 'gagalen - oly mirtinum' one reads: 'Nem die blade ende vrucht van gagel ende zietse in oly,' or, Take the leaves and fruits of myrtle and cook in oil. That again the application of gruit in the brewers' industry is not mentioned could be due to the call to secrecy about the composition of gruit.
    The fact a similar name is used for other herbs caused confusion. In a poem Jacob of Maerlant (around 1268) talks about myrtle for the first time, by which he might mean Myrtus communis, but then follows (Mae):

Myrtus is called gagel
But books say that one can not
the 'nappen' make of it
But I do not know what I say
So grows here gagel on the land nearby
And I doubt what mirtus is.
[sorry for the bad translation]

And indeed, of the small plant myrtle one could not make 'nappen' or vats (laguncula = bottle), but we could also use the explanation that in 13th century Flemish and in Holland (where the poet lived for a long time) with mirtus, bog myrtle was meant.     Konrad Meyenberg (1309-1374) talks about bog myrtle when he writes (Hey noot 69):
'Myrtus haizt ain Mirtelpaum... der paum paz ain Staud denn ain paum, wan er ist klain und wechst gern pei fauhten Steten und ist sein pluom gar ains wunderlichen smackes und die pluet legt man ger in pier, daz man auz wazzen und auz roekn oder aus gersten machet'.
    He thus calls it a small myrtle tree, similar to a shrub, growing on wet ground; the flower is added to beer (of rye or barley).
    That the blueberry has the name Vaccinium myrtillus L. has never eluded anyone blueberries would be used in beer (Bui). The English name for it is wortle or worts, which is probably in closer connection to wort as an herb than as a beer.
    Dodonaeus describes bog myrtle as well, and says that the herb is picked and with fruit brought to market. Brewed in beer it makes people 'seer haest droncken' [quite drunk] (see appendix I at 1554).
L'Obel mentions bog myrtle only as one of many additions to hopped beer (Ob 36).

Resina = hars = herssen = haesch = rumphersen, en Zwaercruyt = 'duris specibus' (durae species)

The following names are found in city accounts of Deventer, detailing the purchases of raw materials for gruit:

1347: 'duris speciebus, dictis serpentien et bekeler ... 16 s' (Cam I 281)
1414: '76 paer zwaercruyts, elc paer [each pair] vor 6 pl. 2 br. ... 22 gul. 23 pl. 2 br.' (Hul 122, 117)
1421: 'hoer uutgeven vor [here spent for] gagelcruyt, zwaercruyt, hoppe ende harsse ...
    4 paer [pair] serpentiins ende [and] bekelers, elc paer 6 1/2 pl. 1 gul. 8 pl.
    32 paer [pair] serpentiins ende [and] bekelers, elc paer 6 1/2 pl. 8 gul. 16 pl.'

In 1398 in Zwolle the 'oude schepenen den nieuwen overdrage 32 mod. crudes, 100 pond hersen en 100 paer zwaer crudes,' or, the old city officials delivered to the new city officials 32 mod. herbs, or bog myrtle.
    From the above I mean to deduce that zwaercruyt the middle Dutch name is for duris specibus, as one called the substance when the receipts were still written in Latin. And it is clear that duris specibus is serpentien and bekeler. It is not clear why zwaercruyt was sold in pairs.
    De Hullu thinks zwaercruyt means zedoar. Zedoar is mentioned by L'Obel (Ob 36) as an additive to [brewing with] hops . The plant is named Curcuma zedoaria Rosc. [white tumeric] and the root [rhizome], which is called zitwerwortel, tastes bitter. In this instance 'zwaer' could be a degeneration of 'zitwer', though this does not match the above citations very well.

Serpentien = laserwort = Laserpitium siler.

    An Umbellifer, it grows in the Alps and the Jura, and also seems to have many surnames like: scherpentanden [sharpteeth], sermontano, seselkraut, laserkraut.

Bekeler = laurel berries = Laurus nobilis L.

    The bay laurel of Southern Europe.

Porsch = marsh rosemary = Ledum palustre L.

    Schulte (Schu) says that this plant grows mostly in Eastern Europe. It is a type of Erica, also called Sumpf-Post, Moerasrozemarijn [bog rosemary] or wilde rozemarijn [wild rosemary] (Kin) as well as alczem, brauerkraut [brewers herb], grantze, gruit, mirtenboum; Schilte thinks, on the other hand, that in West Germany the name porsch also was used for bog myrtle (see also appendix 1 at 1447). De real rosemary is called Rosmarinus officinalis L., and is a labiat.

Salie = sage = Salvia horminium L.

    Also called Sclarea (Lem).

Duizendblad = yarrow = Achillea millefolium L.

    Also called gachel, gruttblome (in Mecklenburg).

[Sage and yarrow are not mentioned in the primary sources, and Doorman does not explain why he included them]

Chemical substances in bog myrtle, marsh rosemary and hop.
    Bog myrtle: In the leaves 0.2% essential oils are found. These consist mostly of terpenes, cineol, esters of fatty acids, high evaporation point alcohols and sesquiterpenes, and also about 0.75% paraffin-hydrocarbons C29H60 and 0.75% palmitine acids. (Pic)
    The fruits turned out to contain 0.5 to 0.6% essential oils, consisting of pinene (40%), sesquiterene (40%), phellandrene and cineol.
    Because terpenes, sesquiterpenes and cineols mainly determine scent and taste, both the leaves and the fruits would be useful; the fruits can only be harvested around May 1st, but have the highest levels of essential oils. (Enk)
    Marsh Rosemary: For this plant a level of 0.3 to 2% of essential oils is noted (Weh II). Others found 0.16 to 0.33%.
    Hops: In the hop cones were found 0.14% to 0.38% of essential oils and these contain among others myrcene, humulene and esters of myrcenol. The hop pollen (lupuline) contains a mix of resins, including humulon and lupulon. (Weh I)
    The bitter taste in hops is due to humulon.
    Bog myrtle and marsh rosemary contain no bitters. If gruit beer was bitter, it would have been due to other additives, probably the resins. Bog myrtle does have a peculiar tart herb-y taste, which apparently was appreciated.