Hey all! So I have two beers that seem to have low attenuation so far. Stout - OG 1.084 on 7.16.2016. FG 1.041 on 8.1.2016 California yeast (WL) APA - OG 1.055 on 7.17.2016. FG 1.027 on 8.1.2016 California yeast (WL) I had anticipated the stout to take a while, recipe called for 90 days of aging - but not the APA. Pitched a proper amount of yest for both (according to the starter calculators) My question really is - is there a way that I can get these FG's lower? To note - the APA has a little funk in the hydro. It's not totally off putting (think saison-esk quality) - but maybe there was a little wild contamination and there was a "yeast war" in my APA that caused low attenuation. The stout tastes amazing - just sweeter than it should be IMO. (Hence thoughts about pitching more yeast to eat up fermentables that I assume are there. Should I worry about the stout? Should I pitch another growth of yeast into these guys? We have plenty of this yeast as we harvested, so it's not a cost really at this point. Should I co pitch some dextrose and yeast into the stout and APA to get things working again? I thought about making the stout starter with the stout and dextrose to get the yeast acclimated. Any help would be neat. Thanks gents!
I've gotten higher attenuation >80% from both Notty and US-05 lately, which is way higher attenuation compared to most other yeasts. I know this might sound crazy to some but you might want to make a yeast starter with one of those two dry yeasts and add that in. If you don't make a starter and just add the dry yeast in, it probably won't work very hard for you. You need to pitch when it is already vigorously fermenting in a starter for this to work. One pack of either one in a decent 1-1.5 liter starter (assuming 5 gallons beer) should do a nice job for you and fairly quickly.
I have no problem with doing a starter, and planned on doing two separate ones. One for the APA and one for the Stout - if that is the advice that I got on this post. I have heard of co-pitching two different yeasts before, but not really in these styles.
What calculator are you using to convert your refractometer readings? If not Sean Terril's, you might want to run your readings through his. But it shouldn't make a huge difference.
Vikeman makes a good point. If you didn't use Sean Terrill's calculator to adjust for alcohol, be aware that his calculator shows that your final gravity might actually be as low as 1.015 for the stout and 1.012 for the APA. Link: http://seanterrill.com/2012/01/06/refractometer-calculator/
My refractometer shows me "hydrometer" readings as well as brix, etc. Those numbers I provided on the 8/1 date were the SG at that time. I am unsure how to use that calculator without the brix degree. Although it totally looks badass. @VikeMan I have not tried several days apart to check. I will do another one Wednesday most likely - I just had initial concern because after 16 days I thought there would be more change, based on my experience with this yeast and similar OG beers (to the APA. The stout is my first bigger beer)
Refractometers are only accurate for OG. Terrill's calculator is pretty much mandatory once there is any alcohol present.
You can use either one. But understand this: With a hydrometer, what you see is what you get. With a refractometer, though, what you see is NOT what you really have. You need to pump all the refractometer data into Sean Terrill's calculator to correct it, otherwise it's way way off.
Both the initial and the final refractometer Brix readings should be run through a calculator. The calculated OG will only be a little different from the SG equivalent from the refractometer's scale. The calculated FG will be a lot different. And the calculator needs to know both readings (i.e. it can't work with just the final reading). If you didn't write down your Brix readings, but did write down the SG equivalent readings from the scale on the right side of your refractometer, just look at your refactometer now (without a sample), and line up the Brix readings with what you recorded for the instrument's SG equivalents. Then you'll have the two Brix readings to enter in the calculator. BTW, your beers are done.
I assume you're talking about the Wort Correction Factor (WCF) in Sean's calculator. I think Sean's currently recommended default is 1.04, which on average works well for the worts Sean typically makes (or at least the ones he was making when he was compiling data) . The WCF corrects for the fact that refractometers are calibrated for pure sucrose solutions, but beer wort is never that (unless you are in prison). The best WCF for any given wort depends on the mix of sugars/dextrins. Without extensive testing, you can never know the exact mix of sugars/dextrins in your wort, so what can you do? When I incorporated Sean's models into BrewCipher, one of the tweaks I made was to calculate and recommend a WCF for each recipe, based on the expected fermentability of the wort, as a proxy for the sugar/dextrin mix. So if you use BrewCipher, the WCF can be automatic, or you can override it with any factor you want.
Cool. Well if I leave the wort correction factor at 1.040 (default) the results show after converting SG to brix, that the stout is 8.2% and the APA is 5.1%. Definitely nearby the expected alcohol content. I saw a spreadsheet for determining your "own" WCF, since it's tied to individual refractometers. It seems cool - I will begin using that on new brews, and maybe even be able to retrofit the last few into it. BrewCipher I have read about - people apparently like your work! I will have to check it out.
I think I've seen that sheet. IIRC it's a combination instrument correction and an "average" wort correction, but doesn't consider the makeup of individual worts. Still, it's probably better than using 1.04 for everything.
