My first brewing experience with the medium BIAC went well, but with lots of question marks flying over my head.
Temperature control seemed great with the system temperature controller, but when measuring at the top of the mash tun with a temperature gauge, or during cooling, the readings were off. For example, during the mash a temp probe in the top of the mash read about 145F while the temp controller read 151F; and all throughout the boil my temp controller read 209F. When cooling, the temp controller said 72F and my temp probe at the top of the wort said 93F. (BTW, my temp probe is seated all the way in and read perfectly with just water on a test run). I called Nathan and he said that with temperature dispersion throughout the vessel that it was normal and given time to regulate the temps will begin to match (which they did). Have any of you more experienced guys/gals seen this?
Same here - don't worry about it too much. Before pitching yeast I definitely give it a good amount of time at 65 or so to make sure the temperature has equalized throughout the wort.
Second. How much volume do you account for yeast/trub loss? I found that I dumped about a gallon and a half to clear the mess from the bottom of the conical (I used about 8 ounces of pellet hops dumped directly into the boil).
I use the same trub loss settings provided by Nathan for the BIAC in Beersmith. Majority of the time I don't even dump trub before pitching yeast unless I'm wanting to harvest. Then when racking I just open up the racking port into a bucket until it runs clear after a few seconds and know all the junk is below the racking port.
Third. My OG/FG gravity readings were low and I am now reading that with a no sparge system, that I should be increasing the malt by about 20-25% to hit my gravity. (reference: Brew magazine article written by John Palmer May/Jun 2002, Skip the Sparge). Do you increase your malt bill to make up for a no sparge system?
Like any other system, adjust the efficiency as necessary once you gather data and adjust your variables. I usually hit 70% pretty consistently so I have left it there.
Lastly. I dialed down the power on the power controller to 25% while mashing. When I went to mash out and increase the mash temperature to 169F it wouldn’t make the temp rise. So, I started to increase the power % slowly and it took 40% power to eventually make the temp rise to 169F. That whole process of figuring that out took 40 minutes. So my question is, what power settings are you using to do the mash out? Do you just crank it up all at once or do it slowly?
25% is the sweet spot that I have found for mashing. 100% and you run the risk of scorching the wort or constantly overshooting your recirc wort/mash temp. And yes, when I do my mashout I raise it to right at 40-42.5% depending on ambient temp.
Seems like with any new system, there is a learning curve.
