Loyalist Dave said:
I think it more likely that LeConte incorrectly identified baking powder as a form of "yeast" since in a "quick bread" it's used as the "leaven". Bannock at the turn of the 20th century was recorded by Kephart as being made with "baking powder biscuit dough" and double the lard normally used in biscuits.... his was the same way, done in a frying pan.
LD
I agree with Dave, as I have never seen a bannock recipe with yeast.
However Yeast has been dried for centuries, despite Fleischman's claim to fame.
The Vikings dried yeast on wooden sticks as did the Norwegians.
However these were used for making wine, beer and mead.
LeConte may have been referring to "pressed yeast", but ultimately his statement may have simply been a testament to a poor cook.
"Before 1872 and as early as 1787, not fewer than 34 patents were issued on “yeast as an article of manufacture” (18 sourdough”types, 5 from treated brewer's yeast, 11 from fermented liquid media).
As mentioned, the oldest patent found on yeast was published in 1787 and was based on the use of fermented potatoes as a growth medium to prepare yeast. While potatoes were renowned for stimulatory action on yeast fermentation, most patented formulations for sourdough preparation were based on milled cereals (malted or not), sometimes grapes or flowers.
Historical context These artisan preparations were intended for bakers or customers who were obliged to make bread without yeast because they could not afford to pay for “pressed yeast” available from beer or alcohol manufacturers. Throughout the 19th century, such ingredients were very popular, especially in Great Britain, France, and the United States.
The taste of bread made with these artisan yeast preparations was sour because large amounts of microorganisms were present in flour, including lactic acid”producing bacteria that grew faster in hydrated flour than miscellaneous yeast species (also present in flour) with variable gassing power. Mainly producing lactic acid and to a lesser extent acetic acid, lactic acid bacteria are poor gas formers, compared to yeasts which do not form acids from fermentable sugars present in flour, mainly glucose, fructose, and maltose freed from starch by the action of endogenous wheat amylases. Because it was highly variable in nature and strongly influenced bread flavor, these spontaneous sourdough”based starters had limited value for large”scale bread manufacturing. "
"In the 19th century, the rapid development of industrial distilleries in Northern European countries led to recovery of distillery by”products and prompted the sale of yeast to bakers as an alternative to brewer's yeast. However, between 1823 and 1860, British distillers were not allowed to sell distillers’ yeast for bread applications which contributed much the rapid development of German, Dutch, and French monopolies in superior pressed yeast for baking (Weir 1991). This partly explains why most patents on brewer's yeast debittering and bleaching were issued in Great Britain. Around 1850, German scientists discovered that distillery yeasts had higher gassing power than brewer's yeasts (Weir 1991). Helped much by their ease of adaptation in different environments, specific yeast strains for bakery applications were then selected according to their performance in distilleries (Gélinas 2009)."
"Around 1780 to 1800, the Dutch process was developed by a gin manufacturer from Schiedam (The Netherlands) that sold a concentrated yeast product for baking applications. Waste yeast production was combined with gin production and gave about 4% to 8% yield (wet yeast/wet grain weight basis). Mash was made of cooked rye and barley malt; after decantation, the supernatant was diluted and seeded with yeast at 18 to 19 °C (Frey 1930). Both floating and bottom”settling yeasts were recovered after washing with water and filtration. No aeration was provided and the taste of this cake of distiller's yeast was milder than brewer's yeast. Yeast traders were very interested in technologies to increase yeast yields. In these days, baker's yeast manufacturing was closely associated to alcohol manufacturing which means that any increase in yeast yields meant that alcohol yields were reduced; however, compared to alcohol, yeast manufacturing was much more lucrative for distilleries (Weir 1991). "
"Much interest was given to the final processing steps for baker's yeast, with 19 patents. In the paste or compressed form (about 25% to 30% solids), yeast is a very suitable material which encouraged manufacturers to develop automatic forming and packaging systems. Especially in the United States and Germany, and as early as 1878, automatic cutting and wrapping equipment was designed to save manual work and reduce yeast losses during its final manufacturing steps."
-Mapping Early Patents on Baker's Yeast Manufacture
Pierre Gélinas-
https://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2010.00122.x