2nd AG attempt and stuck fermentation

[dafbach]

Hi

It appears my 2nd attempt at a 10 litre AG has stalled. I brewed it on the 17th April, used 6grams of US05 and had a decent reaction. This slowed after a couple of days with no airlock movement. I took a reading on the 19th April which showed 1.030, I have taken a reading again today and its still on 1.030.

Its sitting on a heat tray in my garage at a constant temp of approx 20C.

I'm tempted to add a little more yeast.

What are your thoughts please?

 

[Simonh82]

That is very high so you need to do something to get it going again. Can you give us a bit more info. An outline of the recipe, the starting gravity, what type of beer? Did you use lots of speciality grains?

I'd try gently rousing, to get the yeast back into suspension. Adding the other half pack of yeast can't hurt either.

US-05 is generally very reliable and should be able to get the gravity lower than that if nothing was seriously messed up during the mash.

 

[dafbach]

I have made a 10 litre AG using
1.850kg Maris Otter
50g Crystal Malt light
50g Crystal Malt dark
50g Roasted Barley

using Pioneer and Brambling Cross hops.

I sprinkled in 6 grams of Safale US 05 yeast pitched at 22C

OG 1.048

I steeped the grain for 60mins and boiled for 60mins.

 

[Simonh82]

What was your mash temperature? There doesn't seem to be anything odd about it. Hopefully fermentation will restart with a gentle rouse.

 

[wfr42]

I mashed my first ag too high, about 70 degrees and struggled to get it below 1.030

 

[Sandimas]

It's been very cold at night recently - wonder if the air temp in your garage has cooled it down too much, despite being sat on the heat tray? Not sure how well they work, I put my brews in a trug full of water with a fish tank heater.

I'd be tempted to bring it into the warmest room in the house, airing cupboard if possible, chuck 200g of sugar dissolved in a little boiled water in (to give the yeast all the help it can get) and give it a good stir. No need to re-pitch yeast, there should be plenty in there already, it's just run out of puff.

 

[Hops_and_Dreams]

If it doesn't get going again, get some of this:

http://www.ebay.co.uk/itm/Pilsner-e...606281?hash=item338601f109:g:UjAAAOSwWTRWydaS

I bought a couple of dodgy packs of yeast that both got stuck at the 1020 mark. Used a sachet of the enzyme each time and both got down to 1010. It breaks down the more complex sugars to make it easier to ferment. It's a bit old, but there's more info here.

I did try extra yeast, some sugar solution and rousing, but none of these worked. I always keep a pack of this now, just in case.

Oh, the Black IPA that I used in in turned out really nicely too, which was surprising given all of the faffing about!

 

[dafbach]

It's been very cold at night recently - wonder if the air temp in your garage has cooled it down too much, despite being sat on the heat tray? Not sure how well they work, I put my brews in a trug full of water with a fish tank heater.

I'd be tempted to bring it into the warmest room in the house, airing cupboard if possible, chuck 200g of sugar dissolved in a little boiled water in (to give the yeast all the help it can get) and give it a good stir. No need to re-pitch yeast, there should be plenty in there already, it's just run out of puff.

my batch is 10 litres, would you still use 200g of sugar?

 

[dafbach]

What was your mash temperature? There doesn't seem to be anything odd about it. Hopefully fermentation will restart with a gentle rouse.

I brought the temperature to 70C in a pan, added the grains covered the pan and insulated the pan with a towel for the hour.

 

[Cwrw666]

When you add the sugar to your wort, if it froths up it will show that there's nothing wrong with your yeast. So the problem must be that it can't ferment the sugars present in the wort. I've had this with brews stuck at 1020 and added amylase enzyme which breaks down complex sugars to simple ones, and it worked for me.

 

[Sandimas]

I brought the temperature to 70C in a pan, added the grains covered the pan and insulated the pan with a towel for the hour.

Did you measure the temp after adding the grains? I do 10L brews and normally need a strike temperature of 74C before adding the grains, if yours was 70C it may have dropped a bit low after adding the grains.

my batch is 10 litres, would you still use 200g of sugar?

Yes, it won't hurt it you'll just end up with a stronger brew - once stuck, yeast needs all the help it can get to get going again

 

[dafbach]

Did you measure the temp after adding the grains? I do 10L brews and normally need a strike temperature of 74C before adding the grains, if yours was 70C it may have dropped a bit low after adding the grains.



Yes, it won't hurt it you'll just end up with a stronger brew - once stuck, yeast needs all the help it can get to get going again

That may have contributed to it, I didn't take a temp reading on this one after adding grains, but I do recall keep the gas burner on whilst adding just to keep the temperature up.

 

[dafbach]

When you add the sugar to your wort, if it froths up it will show that there's nothing wrong with your yeast. So the problem must be that it can't ferment the sugars present in the wort. I've had this with brews stuck at 1020 and added amylase enzyme which breaks down complex sugars to simple ones, and it worked for me.

Yesterday I added a bit more yeast and gentle stirring, still no movement. I've added 200g of sugar dissolved in boiling water and added that. I got the frothing upon adding, so fingers crossed.

I was looking for a warm room to place the FV in and was talking to myself whilst doing it and was overheard by Er indoors............when she came down off the ceiling :whistle: I placed a blanket around said FV and left it in its happy home in the garage.

 

[Sandimas]

I placed a blanket around said FV and left it in its happy home in the garage.

Can I suggest opening it up briefly and sticking the thermometer into it to see what temp it's at - you're shooting in the dark by wrapping a blanket around it and hoping for the best, if it's too cold you'll never rescue it.

 

[dafbach]

Can I suggest opening it up briefly and sticking the thermometer into it to see what temp it's at - you're shooting in the dark by wrapping a blanket around it and hoping for the best, if it's too cold you'll never rescue it.

It's sat on a heat tray and the temp gauge shows it was at 20C. Airlock activity has began again :thumb: looks like Er indoors hitting the ceiling has woken up the yeast :lol::lol::lol::lol:

 

[Simonh82]

You mentioned that you kept the heat on whilst you mashed in. I think that might have been the problem. It doesn't take much heat to raise the water temperature and I've seen very similar posts where people have left the heat on and ended up with a mash at 75-80oC. You won't know now what the actual mash temp was but in future would mash in with the heat off and then if needs be, apply a little bit of heat very gently to get it up to temp.

If the mash ended up significantly above the optimal temperature then you would get mostly long chain, unfermentable sugars. The fact that the fermentation came back to life with the addition of plain sugar suggests the yeast are healthy enough but you may end up with a very sweet rich beer that is a lot weaker than planned.

The amylase enzyme that someone linked to earlier would be your best bet for dealing with this but I've not tried it myself and I guess you could end up with the opposite extreme of a very thin beer.

 

[JapanBrew]

Most important thing in AG is mash temp. Screw that and it's hard to recover. Different temps, different sugars.

 

[dafbach]

The added sugar boosted fermentation has halted so I'm going to order some amylase enzyme before it sits on the yeast for too long. I'ts dropped down from 1.030 to 1.028 and will test again before adding the amylase enzyme.

Thanks for all your help guys :thumb: