quo libeat vero tempore ex aqua hordeoque bilibres offae ferventi foco vel fictili patina torrentur cinere et carbone, usque dum rubeant. Postea operiuntur in vasis, donec acescant. Hinc fermentum diluitur. Cum fieret autem panis hordeacius, ervi aut cicerculae farina ipse fermentabatur; iustum erat ii librae in v semiodos. Nunc fermentum fit ex ipsa farina, quae subigitur, priusquam additur sal, ad pultis modum decocta et relicta, donec acescat. Vulgo vero nec suffervefaciunt, sed tantum pridie adservata materia utuntur, palamque est naturam acore fermentari, sicut evalidiora esse corpora, quae fermentato pane alantur.
[There is another type of leaven] that is agreeable [to be made] at any time [of the year; it is made] from water and grain [that are formed] into two-pound balls and either heated [directly] on the hearth or baked in a clay plate with ash and charcoal, until the balls are red in color. After this, the [baked balls] are covered in a jar, until they become sour. From here, the yeasty material is soaked [with water]. In the past, when barley bread was made, the flour of chickpeas and bitter vetch was fermented, [and] at a weight of 2 pounds per 5 semiodii [of grain]. Now, the yeast comes from the [barley] flour itself which is kneaded before the salt is added and cooked in the manner of porridge, [before it is] left out to turn sour. Typically, they do not heat [the dough] at all, but, on the day before, they use some saved material [i.e. a starter]. Its nature is to be fermented with sourness, as the bodies which are nourished on fermented bread are stronger.
Pliny tells us about the various kinds of leaven. Although the ancients were not familiar with yeast as a type of organism, they were aware of different methods that would promote leavening or fermentation.
Pliny records several different methods for producing leavened bread. Many of these processes are not dissimilar to beer production and, in fact, would necessarily result in a type of beer (or beer-like beverage) if any residual liquid is present. Pliny describes the leavening material itself as “fermentum,” which, when left out in the air, causes the mixture to sour and the bread to rise. Pliny, however, never uses this same word, “fermentum,” to describe the production or any qualities of beer in any of these passages. This suggests that Pliny was unfamiliar with brewing (not surprising) and/or he did not consider the specific agent that contributes to leavened bread as the same as that which produces beer (i.e. yeast).
The “old method” of leavening is also relevant for this blog. Pliny describes the addition of pulses (specifically bitter vetch, chickpeas) that served as the primary leavening agent in bread. This recalls a past (and ongoing) HBW series about a pulse(lentil)-and-barley beer that Xenophon observes the Armenians drinking in the fourth c. BCE (the specific passage). Is there a connection? Do pulses carry/attract yeast better than barley? It is difficult for me to envision any reason for this. Perhaps, my biology or botany friends know better than I.
In sum, leavened bread: sourdough starters or airborne inoculation.
Please see the “Featured Image.” This is a carbonized loaf of bread recovered from Pompeii. This bread was made during the final days of Pliny the Elder’s (the author) lifetime. When he was thinking about the bread in this passage, he was likely envisioning something very similar to this image.
Wikimedia Commons, Bread from Pompeii, Museum Boscoreale, Photo by Jebulon