LME sugar wash stalled. Please help 🙏

[dave_distills81]

Hi team,

I started a 2 can LME and added 2kg of sugar. Filled to 16.5L in the fermenter. Starting SG was way over (1.15) but in my lack of experience I forged ahead, assuming that with more yeast than I would normally pitch and plenty of nutrient I would still get it down. I used Pure Distilling distillers yeast (which I believe is a turbo and can handle high ABV washes.

Anyway, it went hard for about 3 days. On day four it seemed to have stopped. On day 5 I took a reading. It stalled at 1.04. I added more yeast that I had started in a jar and more nutrient, AND another 2 L of water as I was worried the sugar density was too high that it stressed the yeast into dormancy.
It's now day 8 and there is no budging off 1.03.

What do I do next? I've checked PH it's around 5 or 6. I added a tiny bit of citric. I'm totally lost. Do I just give up and begin stripping runs and hope for the best?
Any advice would be greatly appreciated.
Dave

[TheRealMrMessy]

Heya dave.
You're rocking a pretty high abv wash there, 1.150 down to 1.030 is a solid effort by the yeast, and indicative of almost 15% abv. Not many yeasts will reach that much less go beyond it. Also using LME is going to have an amount of unfermentable stuff so it's not likely you'll get it all the way dry anyway. If you want to try pushing it a bit further, I reckon at this point you'll need to dilute the wash and chuck some fresh yeast in (suggest no more nutrient though).

Sounds like you already have an idea for next time, but you generally don't want to target higher than 1.080 to 1.090 SG to start with - give the yeast a chance to do their thing without making horrible esters etc.

[TheRealMrMessy]

Would edit the post but I'm getting forum errors...
pH probably way low/acidic after that much fermentation. While you could adjust that with some calcium carbonate and try to keep going, the abv alone is probably part of the issue too.

[dave_distills81]

Thanks for the fast reply!

Yeah I agree, I think it's time to let it go and move on to stripping runs and hope that it still tastes ok at the other side. I will definitely bring the SG down if I use LME again before starting. I usually do a simple ffv and start around 1.07 with no issues. I was caught off guard with all the issues you can get starting too high.

Appreciate your quick response my dude! Merry Christmas!

[RobMichelle]

I’ve only had 1 gin is there 2 threads on this or I answered a different thread

[TheRealMrMessy]

Crossed wires Rob :).

[dave_distills81]

One more thing.

If I understand yeast correctly, then something else has happened to stall this though, right? Because, in a healthy environment, wouldn't the yeast continue multiplying and feeding on sugars until the food supply runs out? So, if the reading is 1.03 and there IS sugar, something has gone wrong for them to give up. Is that right?

I assumed it was not enough nutrient, so I added that and some water. It did seem to fizz up and start again but that quickly stopped and then nothing. Temp is stable 24C.

Anyway, I'm going to call it done, and like I said I won't start with anything over 1.08 again, I'm just curious as to what might be causing the yeast to stop working... It's killing me not knowing!

Thanks gang. D

[The Stig]

Yeast needs more than sugar to survive and multiply

[dave_distills81]

Yeast needs more than sugar to survive and multiply

Yes, of course, I should have clarified. Nutrient and correct PH and temps. But assuming that my temps are stable and there is still sugar in the wash, what is the most likely cause of the stall? I used DAP and rast nutrient and even topped them up when it stalled, along with more hydrated yeast. So, is the likely conclusion that the pH dropped off a cliff and THAT'S what caused the stall? Thanks for weighing in, Stig!

[Wellsy]

Don’t forget alcohol content Dave, alcohol is created by yeast as a by product and that does not mean yeast likes to live in high concentrations of it. Just like humans none of us like to live in our own by product,or that of others come to think of it :)

As you said in the other thread best of sticking to a recipe when you first start out as there are lots of variables. Start experimenting once you have a bit of a supply :)

[TheRealMrMessy]

How’d you get on with this Dave?

[dave_distills81]

Okay so here's the update.

After all that buggering around trying to get it going again (which it sort of did but didn't last long. Maybe a day more activity) I decided that FG of 1.035 was as good as it was going to get (SG was 1.10). Plus, I left it for Bout 5 days hoping for it to settle.

The wort didn't smell too great to be honest. At least nowhere near how clean it smelt when it stalled. It had a distinctly acidic turn about it. I wasn't confident. But quickly made stripping runs to get it moving. The stripping runs smelled and tasted a bit sweet to me, which is a first considering I've only ever run sugar washes with varying extras like wheat bran and oats. Once I had the stripping runs done I immediately ran a spirit run with all the low wines on pot mode (just my little air still pro which has both pot and reflux mode). Collected about 1.3L at total ABV of 73 of hearts.

After the spirit run there was a reasonably malty profile which was no longer overly sweet, which I liked. Proofed down to 60 ABV and put into glass jar. For some reason I decided to try one of my French oak staves, even though my gut was telling me American Oak all the way.. dunno, just felt it might be nice to have those vanilla notes. Anyway, a week later on oak and holy hell. I love the smell and it's starting to colour up nicely. Tastes like it will still go a couple more weeks force aging, but I think I'm going to like it! All in all a good learning experience with the LME fermenting and hopefully a problem that didn't ruin it completely!

In the meantime I've started a new ferment with only 1 can on LME, less dextrose, and an SG of 1.05. I know that's low but I didn't want to add more sugar as I was heading out and needed to get the lid on. Anyway, I think I've got this one sorted.

Thanks again to all who posted and set me straight!!