Leavening agent

Transcription

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