I'm looking to embark on a mashing parameter experiment. I want to do lots of small mashes in a thermos with variyng parameters (temp, thickness, pH) and observe its affect on the attenuation. B/c I will do this over the course of many weeks I don't want to rely on fresh liquid yeast. And being cheap I don't want to buy dry yeast just for this experiment.
So I have been thinking about using bread yeast to determine the limit of attenuation for the samples. This will work if bread yeast can only ferment up to maltotriose and none of the dextrines. I already made a test where I pitched bread yeast into 12*P wort that has shown a FG limit of 2.2 *P (with lager yeast) and the bread yeast stopped at 2.4 *P. This would make perfect sense if the bread yeast is an ale yeast and thus cannot ferment maltotriose, but it would be bad if the bread yeast gave up earlier b/c it cannot tolerate the moderate alcohol level of a 12*P beer.
Doesn anyone has additional information on that?
BTW, the sample fermented with the bread yest tastes like a Belgian to me