Have been using a stirplate for the last 5 batches and I cannot get the yeast to flocuate out and attenuate dry. >:(
Brewing familiar 6gal recipes (1.040 - 1.070 OG) with same brewing process, same ingredients (sugar/no sugar), same water, same bottling methods. Use the same yeasts - WY3522, WL550, WY3711. FG is not the problem with the 3522 and 3711 I get FG’s 1.006 and 1.004 but the beer is “sweet”.
Use Mister Malty calculator for starter size, light DME, 1/8 tsp of nutrient, foil on the top, stirplate vortex about 1.5 in wide and 1in deep, good yeast movement. On stirplate for 24hrs, then into frig over night, pulled out and decanted a few hours before pitching.
Bottom line: The yeast will not flocuate out, It will sit for three weeks and I still need to cold crash. The last batch of 3711 left a film on the better bottle and a film in the beer bottles. It will not fully attenuate out the sweetness like it did before the stirplate
Yes, flocuation changes as in extended time in suspension and less attenuation for all. Before my stir plate i found 550 med, 3711 low, and 3522 high for floc. FGs are low but beers not dry as they were.
Also, I use 02 to areate the wort from 60-120sec depending on the gravity
skyler,
Thanks. I have gone up to 36 hours and it sits in the fridge for 8-12hrs before decant. 48 hrs might do the trick but these are not huge beers.
Tubercle ain’t no yeast scientist by no means but this don’t make sense. The stir plate only increases the population of yeast before pitching (and might help the giddy-up a little bit) but nothing should change the flocculation characteristics. Not buying it. Something else is going on.
I can see how floc characteristics can be affected by decanting, but your results seem counter to expectations.
For example, if you decanted and ended up dumping out the yeast still in suspension, then you would be selecting for the more flocculant cells, not the other way around.
For ales and a 1000ml starter, I just stir up and dump in the whole thing, so I get the full population of yeast. For a larger starter I would crash cool it and decant, but if you’re not careful you can dump out some yeast.
The yeast stuck to the bottom of the starter is the more flocculant stuff, so if any is left behind you are selecting for less flocculation.
If I have a 24 hour-old starter, I pitch the whole thing.
At 24 hours, that starter is probably at or near its highest level of activity. Shocking the yeast in this state by chilling the starter is not good for the health of the yeast, I would imagine.
If you want to decant the starter beer and pitch the yeast slurrry, my understanding is that it is best to let the starter run for several days (4-7) to allow the yeast to build up nutrient reserves, and then chill to force them to floc.
I can’t say why exactly what you are doing is causing that result, but I would suggest you change your procedure and see if that helps.
zorch,
I used to shake and pitch at high kruesen, 8-12hrs.
So 24hrs is too short for good build up on a stirplate? What do you do? Pitch a whole 2L starter at onceafter 24 hrs or wait 4-7days to fully ferment out.
Somewhere I got it into my head that 24-36 hours is good for a stir plate then decant anything over 1 liter because possibility of off-flavors - cold crash to decant. If the time is too short that would explain the low attenuation.
I know you said same ingredients but you follow it with ‘sugar/no sugar’ do you mean each time you have brewed it there is x pounds of two row and n pounds of munich etc? or do you mean x pounds of Great Western two row etc. If you are using a new maltsters products or a new brand of extract that could also result in a big difference in flavour. The last two batches I brewed have a distinctly similar sweetness and full mouth feel that I suspect is the result of the Gambrinus pale malt I used. It is the only ingredient that is the same between the two batches but they both have this same distinct sweetness.
The only thing I can think of is that you might be prematurely cold crashing the starter. I have no problems after 48 hours, but 24 might be cutting it close.
You should be running you stir plate until the fermentation is completely finished and then cold crashing and decanting the spent starter beer on top. If you are pitching at high krausen you are not taking full advantage of cell growth. Also, it may only take 24 hours or it may take 48. I usually give myself 2 or 3 days to be sure and to provide time to cold crash.
One minor suggestion (it probably made zero difference but fyi); you don’t need that big of a vortex in the starter. Just a tiny dimple in the middle is all you need. The stirplate is more about releasing CO2 (to reduce CO2 stress) and keeping everything in suspension, it’s not really about adding O2. Very little O2 is making it into that flask with foil on top and positive CO2 pressure from the ferment.
I use 1600mL on a 12-gallon batch, so using 2L on a 6-gallon seems to be a bit much.
I had a Belgian Golden Strong Ale that we made a few months ago. Made a starter and everything seemed okay. Pitched the starter and fermentation was sluggish. I had to repitch another starter to get it to ferment out. When it was done even gelatin couldn’t get all of the yeast out of suspension. I haven’t figured out what could have caused the problem, but more than likely it was low initial fermentation temperature for the yeast I was using (thanks, 20/20 hindsight).
I suggest making your starter at the temperature you’re going to pitch it and make a smaller starter, something along the lines of 600mL - 1L tops. I usually pitch 18 hours after I make the starter without cold crashing or decanting.
All of which is exactly the opposite of what I do and I have no issues. I make all starters at room temp without regard to the temp of the beer. I make 2-3 qt. starters. I let them go for 3 days, crash and decant. All of which is to say that there’s more than one way to make great beer.
In most cases, and always if the starter is > 1.25 liters or so, then I’ll let it go for about 4 days, then stick it in the fridge for 2-3 days, decant the starter wort and pitch the yeast.
I will sometimes pitch the whole starter if it’s around 1L. In that case, I usually try to shoot for 12-18 hours.
Prior to using a stir plate we used to make 1.5 - 2 gallons of starter for each 12-gallon batch. We bought a 3-gallon carboy just to do starters in. But since using a stir plate is more efficient and produces better results, we were able to trim down our starter to 1.4L per 12-gallon batch.
And I agree there’s more than one way to make great beer! I wonder if I have enough time in my life to try them all…