I've been wanting to do some controlled mash experiments for quite a while. Well, I haven't been brewing regularly since 2011, so it hasn't made much sense to work on this. Now that I'm back in the saddle (mash tun?), it's time to start.
The first experiment idea came from Union Jack thread in the recipe forum. Firestone Walker is said to use a step mash to get higher fermentability in their IPA. I used a 145x45-158x30 mash schedule for my Union Jack clone (still fermenting). In the thread there was some commentary from people who have used similar step mashes but had not really noticed much difference. HERMSman posted that he had attenuated a high gravity IPA from 1.080(?) down to below 1.010 using the stepped method. Having used this step mash method for the first time it was a natural start for my mashing experimentation.
Of course, this is also a common method in German brewing, referred to as a Hochkurz mash (see bottom of Kai's page on infusion mashing). Again, supposedly done to increase wort fermentability.
I'm going to complete two mashes, one stepped, one single infusion. Single batch sparge. The malt bill is just 2 row pale, 1.3 qt/lb. I'm going to record refractometer readings throughout the mashes, first wort gravity, pre-boil grav (planned 15 min boil). The worts will be force fermented using dry bread yeast in order to determine the limit of attenuation of each wort. Ultimately the idea is to see if there is any difference in first wort gravity, OG and limit of attenuation between the two worts. If there are any additional ideas on information to collect, I'm open to suggestions.