It was recently pointed out to me that commercial yeast often contains oil additives. This was news to me and so I did a bit of research. It’s true. All bulk yeast manufactures add something called ‘Sorbitan monostearate’. It is an emulsifier that manufacturers use to coat yeast cells and protect them from damage by oxygen and assists in the rehydration of the yeast.
Sorbitan monostearate is a mixture of partial stearic and palmitic acid esters of sorbitol and its mono- and dianhydrides. Generally these are derived from plants, most often corn. As I learned quite a while back stearic indicate fats and in this case we are talking about plant fats which falls into the category of vegetable oil derivatives.
Thankfully the little three packs of yeast often don’t have sorbitan monostearate added. The reason is that the packets of dry yeast do not need it as the packet itself seals the yeast away from air, making the additive redundant. Red Star says on its website: “RED STAR® and bakipan® Active Dry Yeast packets in a strip of three ¼-ounce packets does not contain sorbitan monostearate.” I was unable to tell from Fleischmann’s website if they have sorbitan monostearate in their three packet product or not. It is important to check the ingredient list on packets. I will be buying some packets but they are pretty expensive to use regularly.
Unfortunately most yeast used in commercial products is bought in bulk, meaning that it is usually adulterated with the sorbitan monostearate, making any product that list ‘yeast’ as an ingredient potentially unsafe for those of us who have allergies to vegetable oils.
It is possible to catch wild yeast and make a homemade sourdough. It can take a few tries to be successful but usually local yeasts are stronger and more flavorful than commercial yeast any day. I used to have a wonderful sourdough starter that I maintained for several years. Eventually I forgot to feed it and it died but the bread it made while it lasted was wonderful. Here is a pretty good blog post about how to start sourdough from scratch.
If you, like me, are gluten free you can still grow a home starter with gluten free flour. I have yet to try making a gluten free sourdough starter but I found this great post about it here I’ve read about this more than once and as soon as I have the time and energy I think I will try it. After all I just found out I can’t use commercial yeast anymore!
Links included in post: http://wholenewmom.com/recipes/gluten-free-sourdough-starter/