Galliae et hispaniae frumento in potum resoluto quibus diximus generibus spuma ita concreta pro fermento utuntur, qua de causa levior illis quam ceteris panis.
When the grain of Gaul and Spain – the types of which we spoke about earlier – is made into a drink, they use the foam that forms during fermentation [for their bread]; because of this, the bread there is lighter than breads elsewhere.
Pliny the Elder discusses the different qualities of wheat from regions in the Roman Empire.
The people of Gaul and Spain were notorious beer drinkers in antiquity (see 1, 2, 3, 4, 5, 6, 7, 8). This was certainly helped by (or an impetus for?) their prolific growing of grain (see The Grains of Gaul and Spain).
As any homebrewer knows, a thick layer of yeast-y and protein-y goodness, the “krausen,” rises to the surface of beer during active fermentation. The krausen then sinks to the bottom of the vessel when fermentation comes to an end. Because the krausen is so rich with yeast, it can be harvested and pitched into fresh wort to ferment a new beer or help with the carbonation of a finished beer. This is practice, “top-cropping,” is not at all uncommon. According to Pliny the Elder, however, the people of Gaul and Spain had more uses for the krausen than just making more beer. In one of BCS’s first entries, we learned that Gallic women used the krausen (“spuma”) as a face moisturizer. And here, we are told that the krausen was also pitched into bread dough as a leavener. Although beer yeast and baker’s yeast are different strains of Saccharomyces cerevisiae, this method has been used for centuries after the Roman period (and likely before, too) – called in some places “barm bread.”
Pliny claims that this method helped make the bread of Gaul and Spain so light and fluffy. Is this the case? You will have to wait until our next homebrew experiment to find out!
Pliny the Elder (23-79 CE)
Wikimedia Commons. “krausen” Jswmesq. CC BY-SA 2.5