Fermentation troubleshooting

[mtbiker278]

I have two beers fermenting, well sort of, and I want to figure out the proper series of troubleshooting steps before doing something else. I know there's a lot of "Help my fermentation is stuck" threads, and most say to RDWHAHB, but I just want to run through the sequence of steps for trouble shooting.

Beer #1: Scottish 80/-, 6gal, Mash @ 158F, OG 1.052, FG 1.024 measured at day 7, Expected FG 1.014, Yeast - 2 vials WLP028, Areation - shaking, signs of ferm ~12hrs, Ferm temp 62-65F (Lower than it should be).

The first step I've taken is to move the fermenter to a warmer area and let it get to a higher temp. The WLP028 has a low temp of 65F, so I'm thinking it might have stalled because of the lower 62F temps. I'm waiting to see if that helps with the FG, but I think the next step is to rouse the yeast with gentle swirling (no splashing/aeration). After that I think it might be time to add some yeast. If so can I just add say a packet of S-05, do I need a starter, does it need 02?

Beer #2: DFH 60min IPA Clone 3.0, 6gal, Mash @ 150F, OG 1.064, FG @ 1.020 @ day 16, expected FG 1.014, Yeast - washed S-04 with 2qt starter (1.025 OG - probably too low), Aeration -shaking, signs of ferm ~12 hrs, Ferm temp ~68F.

This beer I'm not sure what to do with. It tastes really sweet compared to the last batch I made, but it does have some different malts in there. I added another two jars of washed yeast on day 16 in hopes that it would bring the FG down to where it should be. Should I have left it be thinkng the FG would get there eventually? Would adding a fresh packet of S-04 been better?

Ultimately I think my main issues are lack of proper oxygen content, and improper yeast culture on the DFH starter (1st time doing one).

Thanks for the input!

 

[BillyBroas]

I'd say you're taking the right steps with #1. Let it warm, rouse the yeast, and see if that does it. If not, I would pitch a small active starter in there. And yes, aerate the starter.

#2 isn't too far from the potential FG. You're apparent attenuation is at 69% and S-04 usually attenuates in the low 70's. The culprits are probably oxygen content and unhealthy yeast as you stated. If you wanted to get the extra points out of it you could add an active starter as in #1. Good luck!

 

[mtbiker278]

What exactly would constitue a small active starter? I'm guessing something like 1 pint starter @ 1.040 at high krausen? Would I pitch a packet of the S-04 or 05 into said starter? Or more like half a packet?

I don't have a stirplate yet, but I did just get an aquarium pump to aerate my future batches. Could I use that to keep it aerated while the starter reaches high krausen?

Thanks again!

 

[BillyBroas]

I was thinking 500ml so yea that's about right. 05 is a good choice because it's fairly high attenuating and clean. I would do half the packet & rehydrate like usual. You want to get some yeast growth and the dry yeast has a ton of cells, so a higher pitching rate wouldn't give you much growth. Don't worry about the aquarium pump, just shake it. You'll get about the same aeration with less hassle.

Try the other options first, and also look into yeast energizer. I've never used it for stuck fermentations but have heard good things.

158 is a pretty high mash temp so you you may not have many fermentable sugars left, but I would think you could get a few more points.

 

[mtbiker278]

Well I roused the yeast cakes on both batches just to see if that'll help. There was some bubbling of the airlock afterwards, but I'm thinking it might just be off gassing. I'll take another gravity reading at the end of the week. I picked up some DME and a packet of S-05 to make a starter. I figure if batch #1 is still high I'll hit it with a starter. #2 I'm thinking I'll just leave alone and focus on the next batch. After rousing I added my hops per the recipe I'm working on. It's already looking like it's settling out so I'll probably rack and keg this weekend and let it condition for a while. #1 is in a bucket so I can't tell what's going on but I still have another 1.5 weeks in the typical 3 week primary. Maybe I'll let it go longer.

The mash temp was pretty high at 158F, but should still be in the range for the Alpha amalayse to do it's work. Beersmith lists it as a "Full body mash temp" which is what I was going for on the Scottish 80/-. I did see the yeast energizer, but I found it in the wine section (shouldn't matter, but thought it odd). I might try if this happens again. I think one of my problems is as my process evolves I've been changing too many variables at once and need to slow down the "process development" a bit.

I picked up some pH test strips to check the next time I'm mashing. One difference between this and the last couple of batches was I didn't bother to run my tapwater through the PUR filter (needed to be replaced). I'm thinking about getting a larger charcoal filter to run through instead of waiting forever for the PUR to give me my 8gal.

Thanks again!