Chemical Leavening Discoveries Part 1


welcome to exploring the 18th century
with James Townsend inside today we’re starting a series of in-depth episodes are related to leavening and
specifically chemical leavening today I’m joined by Kevin Carter he’s
the guy who’s usually behind the camera he does a lot of the research and
writing here at James Townsend and son and he also construct the catalog welcome Kevin, thank you, today we’re
going to be talking about about leavening yes you know I think a
great place to start today would be to kind of step back and review the different types of leavening that were used in the 18th
century we talked a little bit about this in a
previous video that we produced couple years ago and I think it might be just a really good jumping-off point
into into our research first of all there’s Barm which is yeast that you would get, liquid yeast you
would get from the brewer. When you look in the 18th century English
cookbooks when they use the word “Yeast” or barm those terms generally
interchangeable and and barm is that foam that develops on the top of a
batch beer its brewing the krausen and they would sell it in liquid form
pints, and that’s one of the hint you getting
the recipes when they say a pint of yeast today would say “a pint of yeast”
what are they talking about they actually mean by barm liquid least
it wasn’t very concentrated the barm is usually the the foam or the krausen that’s off the top of the beer but there’s another kind other yeast
right right the French would use the spent yeast of the
bottom the beer the lees and there is a 1830 reference the talks about how they would
actually take that spent yeast put in bags, let the
beer drain out then wash it and then dry in into cakes and
that’s a nineteenth-century resource I would probably say that that was growing in popularity in the
nineteenth century eighteenth-century there was more use of “old dough” techniques yes yes the leaven, right what they would call
leaven or old dough right, where they would take accually
a chunk of the dough from the previous batch, so off
made start off with some kind ever a yeast from the brewer right the very
first batch and then every subsequent batch they
would just use some old dough from last yesterday’s batch or two days ago or what ever, the last time they baked. Especially the commercial baker and he wouldn’t do take a lump in
the dough from the batch of bread, probably a big lump, and then they would put it they would store it
either in flour or in salt and it would keep for quite a
while. Now in warmer temperatures that leaven would often times go sour and then they would need to
refresh with either barm or you start over. You don’t see any references to English
eighteenth-century wild yeast culture development people
didn’t say oh you don’t have any use just leave
this out and it will develop its own that isn’t to say that they didn’t do
that in other cultures German sourdough bread say you know any
kind in Northern European Rye breads were sourdough, even in
america there is a brand called yankee sour bread likely from other cultural mix is that they’d people in North America had that the British, It’s like they are in their own little culture and they’re going to do what they think is
right and they weren’t they were not excited about
sour breads They didn’t want sour breads. So anyway
again in Review we have barm we have leaven we also have mechanical
leavening which usually involved eggs or specifically egg whites where they
would sit and whip those things up and and until they were infused with air and then they would gently fold that
into a cake batter to keep to preserve the air in the batter us so we
had mechanical leavening as well Then there’s this issue this matter
of chemical leavening a matter in great debate has to when that started and we’re gonna be looking closer into that.
Dig into that here’s one here’s one little idea I am going to throw this at you. I haven’t talked about this before
when we did the fritters we added the ale and it was a modern ail of course, it’s
carbonated and it actually fluffed up the batter well you know it’s interesting you say
that there are eighteenth-century references to some using
carbonated water in bread to improve, they would say improve
the fermentation that what was happening was that
carbonation was was releasing the gas so you mix up and it froths
right up right so there’s there’s even reference
of Sarasoda Springs in New York on that apparently been a carbonated water source and the bakers in that area produce superior
bread they also even tried to sort a inject
air into dough they were doing weird things in
late eighteenth-century saying could we do
this does this work right I found one reference to the differences
in even in in kneading methods English bakers
apparently with thrust their fists into the dough and then open their fingers to try and
get as much air into the dough was they kneaded it, moving the bottom
dough up to the top and rotating and they would do that for a long time people in the 18th century really didn’t
know what was happening with yeast and there was
this concept called fixed air okay even the earliest mentions the chemical leavenings by the chemists
would talk about how these compounds contained fixed air
that would be released by the heat They believe that the same thing
was happening with yeast that their little pockets of air, compressed air little nodules of compressed air
right, you see that idea carried over into mechanical leavening where they’re
actually injecting air into the eggs you know fixing the air into the eggs for it to be released later on and during the baking process it wasn’t
until 1830-1840 that it was discovered that the yeast is alive it is an organism, it’s a plant it’s a mold, and it’s
actually producing carbolic acid or carbon dioxide as a
result They knew what worked, empirically, right and so they came up with all these
different processes to to make things work right and we’re gonna talk about that in another episode, but how that even
applied to the earliest uses a chemical leavening, so the earliest uses of chemical leavening? Is that is the next episode? yes, The next episode we’re going to be
delving deeper into this the very kernel, the very beginning of
the ideas of chemical leavening. If you’re new to
the channel make sure to subscribe you can also check this link and we’ll take you
directly to our website and you can request a print catalog
thanks so much for watching

Comments 37

  • Excellent advanced discussion!  Thanks guys!

  • I am stoked about this. One I am keen to try is harts-horn. Scandinavian as far as I know. 

  • If Kevin is in front of the camera, then who is behind it?

  • Excellent informative video.

  • I am going to enjoy this series, I admit I know absolutely nothing about barm, or most other forms of yeast besides taking chunks of dough in salt or wild yeasts. 
    Bookmarking this for discussions with my Haymarsh Homemakers society meetings! 
    THANK YOU! 

  • I LOVED this video.  I love hearing about historic thinking on science; misconceptions in particular.  I loved learned about the concept of "fixed air". I had no idea that colonial English didn't use wild yeast; that seriously surprised me.  You've inspired me to wander off and do some research on my own, and I love that too!

  • This series is awesome!

  • beaten biscuits – that was one was to make them and "slapping" the dough on the table instead of kneading 

  • So interesting! I love to bake yeast breads! I'm looking forward to trying some of your leavening types in my whole grain loaves. We have some micro breweries nearby, I'm going to inquire if they might sell "barm".
    Thanks for sharing your information.

  • "wild yeasts" have been used in making lambic & gueuze beers in Flanders/Belgium for centuries.  Pretty sure they didn't know how it worked, only that it did work.

  • I actually just made my first sourdough leavening "starter" last night!  I can't wait to see how the natural yeast works compared to the commercial active dry yeast I have always used.

  • Kevin scares me please put him back behind the camera.

  • Great info! Thanks Guys!

  • This was so brilliant a discussion. Learned a lot and am a devoted viewer/fan.

  • The old way of brewing Sake' in Japan relied on airborne yeasts, which contributed to regional flavors that were unique.

  • Nice to see Kevin in front of the camera for a change.  One of the better blokes in your lot.  Loved his videos about the pottery you sell.   I've bought several of his pieces, love the pie plates they've become a standard part of my baking. 

  • Dorothy Hartley in her Book Lost Country Life reasons on p 191 that Yeast bread has not proved to be used before the 18th century, but realizing the variety of fungus molds and yeasts that were used in brewing, and the spores that remained alive in the wooden bowls and troughs, it would be a queer thing if some woman did not make use of them somewhere. (The increased size of St Brigid's bread when baked was considered a miracle.) Early manuscripts show very smooth well-risen buns, so there was certainly some form of leaven in use. 

  • Just wondering, after reviewing the Passover traditions, it lead me to think, this would be first used around 1000 BC (or so). It says to clean your house of all leavening agents…which means that there was some.  This lead me to think, was the first mention of chemical leavening, not just the mechanical leavening (whipped egg whites, etc.)  Next, I found this:
    http://www.jewishrecipes.org/jewish-foods/bread.html
    Would this be the oldest occurrence to chemical leavening?
    Thanks.

  • I use Hartshorn in cookies I make called Springerle

  • Thanks for your videos.  They're wonderful! 

    Just an FYI:  My husband and I were kind of thrown when Kevin stated that yeast is a mold/mould.  We thought it was a fungus and since all molds are fungi but not all fungi are molds (recently learned), we looked it up.  We learned that yeast is a fungus that adopts a single celled growth habit.

  • I used to get my yeast from the outside of red cabbage, Its the white coloration on the outside of the cabbage, Gently wash it off using your fingers so as not to kill the yeast with pressure into sugar water. No soap and then add flour and watch it rise.

  • I've found this topic very interesting for some years now, hard to get good info. Very happy to see these videos!

  • The word "right" was said 64 times in this video between the two of you. That is an average of 8 times per minute, or once every 7.5 seconds.

    Thank you for your videos – they are quite interesting.

  • I always assumed that the 'and Son' of James Townsend and Son meant that your son did the behind the camera work, but apparently not! How does your son contribute to the channel?

  • I was googling bread making in the 18th century earlier this week. Turns out that I only needed to hope on YouTube. Great channel.

  • Respects to Kevin's work.

  • watch out, this series is special!

  • No mention of sourdough which predates the use of barm. I suspect that sourdough leavening was still in widespread use during this time.

  • I've always wondered about this! I want more Kevin, just want to sit and listen to him tell me all the historical things.
    How did they figure out bread in the first place?

  • Where can I get the link to order the birch whisk?

  • It's very difficult to understand how yeast works if everyone believes that no living things could exist which are smaller than humans can witness (it was believed that the Earth was created for man, so it would make no sense for there to be living creatures we couldn't even see that could affect us… this was the biggest opposition to the germ theory of disease and came from the church).

  • Is old dough also referred to as bread sponge?

  • love the series my family has a bread recipe that has no yeast in it its called salt risen bread it uses corn meal and potatoes with scaled milk to make a leavening agent I will ask if I can share it with you its kind of a guarded secret LOL it evolves a lot of kneading at least 60 time a loaf and it is a very heavy bread but very good

  • Kevin reminds me of Hank from Breaking Bad.

  • This is extremely interesting! Who knew? I thought bread was, well, boring.

  • All these people here saying that Metis is pronounced May-tees should know that it is a French word, and In French it is pronounced Me tis, with a very short, clipped e. In the international Phonetic alphabet it would be written as /me.tis/
    It's only in Canadian English that they put in the Mey, or Meh sound. I guess the Canadians have to put in an eh, somewhere into every thing, eh? 😀

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