Stuck fermentation

[welly2]

Where did you buy potassium iodine Welly?

No potassium iodine, just used iodophor which I believe works perfectly well for doing an iodine test.

 

[MHB]

No where near as well as proper Starch Indicator, Its a blend of Iodine and Potassium Iodide usually in 20-30% alcohol and some times with a few other ingredients to make it more sensitive.
Made properly it can show positive for ppb levels of starch and is very clear in its indication at brewing concentrations.
Mark

 

[Jack of all biers]

Welly,
Don't bottle yet (unless I'm too late). I just racked an under attentuated ESB to secondary (cube) yesterday and found the racking had stirred up the yeasties enough that they decided to give it another go swelling the cube twice today already.

My ESB 50L was split into two 25L lots and I was experimenting with two yeasts, Wyeast 1968 London ESB and 1099 Whitbread. The Whitbread was slow to swell in the pack, whereas the ESB was ready to explode within two hours. I delayed pitching the Whitbread by two hours until it had also swelled, but the lag time for it was about 10 hours more than the ESB. The FG for the London ESB yeast was 1015 (calculated 71% attentuation), but the Whitbread was 1022. Same wort, just slacker yeast that gave up until it got stirred up by the racking. There is significantly more yeast on the bottom of the Whitbread cube and there is a small krausen also. Before anyone says "it could be infected", lets just say that the same sanitation proceedures were for both batches, so I doubt it is an infection of one cube that suddenly took hold within 12hrs of racking.

Maybe consider racking or rousing your yeast in primary.

 

[Futur]

My recommendation for every batch is a fast ferment test. Put a small quantity of wort into a Flask on a stir plate once you've just pitched yeast. This will ferment out within a day or two at room temperature and show you exactly what your fg of the batch should be.

 

[mofox1]

No where near as well as proper Starch Indicator, Its a blend of Iodine and Potassium Iodide usually in 20-30% alcohol and some times with a few other ingredients to make it more sensitive.
Made properly it can show positive for ppb levels of starch and is very clear in its indication at brewing concentrations.
Mark

You got a location we can buy this MHB? I've tried betadine as an indicator, but AFAICT it's fairly useless in the brewery.

I can see this iodine tincture at Chem Pro, which contains both iodine and potassium iodide. This the right sort of product? If so, I just need to find a source closer to me...

 

[Brewno Marz]

Restart of thread and on topic.

Made a small batch (20 litre) of oatmeal stout on Good Friday and used Fermentis S-04 yeast. Fermentation took off and SG got to 1.020 in 3 days. Yesterday, 4 days further on and still at 1.020 and no signs of yeast in suspension. So, I gave the fermenter a big shake and then today still no movement. SG stuck at 1.020 and no airlock activity. First thought was I got my mash temp wrong, but I brewed it in the morning before any beers were consumed! I did a second brew, an APA, on the same day (after beers were consumed and one may have forgot to add the crystal malt...) and it was down to 1.009 today. The APA is in a conical fermenter with my "go to yeast " Nottngham. So, drew off about 100ml of the Notty yeast and pitched it in the stout. Within 30 minutes the airlock was bubbling and is still going strong. Is this a characteristic of the S-04 yeast?

P.S. the APA may be saved. Did a mini mash of the crystal with a bit of pale malt for conversion, then boiled it with a few extra grams of Super Pride & added it to the fermenter at day 5. Seems to have worked!

 

[Danscraftbeer]

Restart of thread and on topic.

Made a small batch (20 litre) of oatmeal stout on Good Friday and used Fermentis S-04 yeast. Fermentation took off and SG got to 1.020 in 3 days. Yesterday, 4 days further on and still at 1.020 and no signs of yeast in suspension. So, I gave the fermenter a big shake and then today still no movement. SG stuck at 1.020 and no airlock activity. Is this a characteristic of the S-04 yeast?

Yes. There is many comments and conversation on S-04 doing this. 1.020 is the common number. There is a little tlc you can do to get it to work better but I just don't use it but many do with good results.

 

[GalBrew]

Yes. There is many comments and conversation on S-04 doing this. 1.020 is the common number. There is a little tlc you can do to get it to work better but I just don't use it but many do with good results.

If only I had a dollar for every time I've responded to this. S-04 is a perfectly fine yeast, you just have to know it's quirks. Search for one of my previous responses for specifics. [emoji106]

 

[GalBrew]

One of the reasons i persisted with s-04 is that it is such a good flocculator. Once it's done it drops like a brick leaving very clear beer for very little effort. It's my go to yeast for all dark ales. I even saw a blog post of the Mad Fermentationist where he made a NEIPA with s-04 and it worked out ok. A very versatile yeast.

 

[Brewno Marz]

Thanks for the confirmation. I found the S-04 dropped really quickly and the samples I took had virtually no yeast in suspension. The little bit of Notty slurry I added got the brew down to 1.010 after a day and has now dropped out of suspension too. So, keg Tuesday and see how it ends up.