Sweet stout high FG

[MegaMash]

Hi, This was the 1st Stout i brewed on my all grain system. Was about 53% pale malt, 12% munich, 6.5% Lactose and the rest made up of oats, black malts and roasted barley. Mashed at 70C and was hoping for a FG of 1.023. Fermented at 18C with US05, really took off after a day and flew down to 1.042 in about 4 days then just stuck there. I tryed rousing the yeast with CO2 and upped the temp to 20c but didnt help much and dropped only another point to 1.041.

I think my high mash temp has left a lot of un-fermentable sugars in the the beer. I had a tube of WL007 english ale yeast in the fridge so thinking to make a 2L starter and pitch this in just incase the US05 yeast have given up early. I also though of using amylase but dont want to go down that route.

It tastes like a nice stout but ideally want to get the FG down to something more sensible and lift the alcohol closer to the 6.6% i was shooting for. Was thinking of possibly making another brew and blending them together to produce something less sweet.

Has anyone got any experience in blending a high FG beer with a 2nd batch to rectify the problem?

 

[LLBeanJ]

Yes, you did mash a little high, but that doesn't explain being off by that much. You're not measuring FG with a refractometer, are you?

 

[specharka]

Hi, This was the 1st Stout i brewed on my all grain system. Was about 53% pale malt, 12% munich, 6.5% Lactose and the rest made up of oats, black malts and roasted barley. Mashed at 70C and was hoping for a FG of 1.023. Fermented at 18C with US05, really took off after a day and flew down to 1.042 in about 4 days then just stuck there. I tryed rousing the yeast with CO2 and upped the temp to 20c but didnt help much and dropped only another point to 1.041.

I think my high mash temp has left a lot of un-fermentable sugars in the the beer. I had a tube of WL007 english ale yeast in the fridge so thinking to make a 2L starter and pitch this in just incase the US05 yeast have given up early. I also though of using amylase but dont want to go down that route.

It tastes like a nice stout but ideally want to get the FG down to something more sensible and lift the alcohol closer to the 6.6% i was shooting for. Was thinking of possibly making another brew and blending them together to produce something less sweet.

Has anyone got any experience in blending a high FG beer with a 2nd batch to rectify the problem?

Yes. I recently did this to a barleywine that was stuck at 1.072 (from 1.137 O.G.). After blending with a lower OG red ale, I was able to achieve a FG of 1.028. Haven't sampled it extensively yet but it tastes pretty good.

My recommendation would be to find a decent dry stout recipe (there are tons) and blend the sweet stout into the dry stout at high krausen. This will minimize any oxidation that would otherwise occur due to blending. If you want to maintain 6.6% ABV you can proportion your grain bill to cater to a higher dry stout ABV.

In the future, limit your adjunct content to less than 25%. Otherwise you're going to see issues with mash fermentability.

 

[Qhrumphf]

That does sound like a refractometer reading. You can't use a refractometer for FG without correcting for the presence of alcohol (there are a number of online calculators to do so). Uncorrected, it will read abnormally high as ethanol has a completely different refractive index than sucrose as the refractomer is designed for (fortunately for us wort is mostly maltose which has an almost identical index to sucrose).

However, if you're using a hydrometer, then there may be a problem, or it may simply be where it's going to finish, which I could potentially see happening. What was your OG? My Sweet Stout is also mashed at 158F/70C, and I use a higher percentage of lactose (10%), and a lower attenuating yeast, but I only get ~52% apparent attenuation on mine and finish ~5.5°P/1.022 or so (I'm aiming for a low alcohol breakfast type beer with it, so that's by design). If you started at a much higher gravity than I do (which your stall point is about where mine starts) then your FG is possible.

 

[Owly055]

70C / 158 F is a very high mash temp, and inevitably will result in more unfermentable sugars. Personally, I would add Amylase (AG300 is my favorite), to the fermenter, and leave it to ferment further....perhaps a month or two, stouts need time to age anyway in my opinion.

 

[MegaMash]

no, Im not measuring with a refractometer, im using a hydrometer. Sorry, i forgot got to mention my OG was 1.073 which I think is not very high.

Qhrumphf: Going from your figures my FG sounds about right then

Owly055: Ive heard that amylase doesnt know when to stop. If i used AG300 would i retain a gravity around 1.020 naturally or would i need to manually stop it? and how?

Thanks

 

[Owly055]

no, Im not measuring with a refractometer, im using a hydrometer. Sorry, i forgot got to mention my OG was 1.073 which I think is not very high.

Qhrumphf: Going from your figures my FG sounds about right then

Owly055: Ive heard that amylase doesnt know when to stop. If i used AG300 would i retain a gravity around 1.020 naturally or would i need to manually stop it? and how?

Thanks

I think there is some truth in this perhaps, but your yeast will only reach a certain attenuation, and personally I prefer a dry stout anyway.


H.W.

 

[Pappers_]

I presume you don't want a dry stout, otherwise you would not have added lactose, mashed at 158, and called it a sweet stout. I think your idea about brewing another beer to blend is a good one. The suggestion above to mix during the second beer's fermentation is interesting and could work, but its not what most folks do when they blend beers. Generally, we brew two different beers and let them both ferment out completely. Then, at kegging or bottling, we blend them to taste. In other words, we add figure out the proportions of beer #1 and beer #2 to add based on our tasting.

Also, 100% agree with the thoughts shared above that your issue is your grain bill and mash temp. 158F isn't unusual for a sweet stout, but with your grain bill, the two factors combined to give you a ton of nonfermentables.

Good luck with the blending, sounds like a great plan!

 

[MegaMash]

I ended up making a started with some WL007 yeast I had in the fridge and added it 2 days after making it. It was the wrong decision. I then pitched the whole starter instead of just the yeast cake and it has some off flavours now compared to before the starter when it was a slightly sweet but nice tasting stout. In hindsight I should have just kegged the sweet stout and drunk it or blended it at a later date with a dry stout.

Not sure what to do with this one now, might just dump it or save it for a very rainy day. Cheers for the advise

 

[MegaMash]

Further update, thankfully some of those off flavours are not so noticeable now, possibly the yeast have consumed them. Going to crash cool tomorrow and keg in a few days, then hopefully blend in the not so long future!

 

[Brew_Meister_General]

I also thought of using amylase but dont want to go down that route.

Have you used it before as I was planning on putting some in my current batch which is also a sweet stout, although I'm doing it because I didn't get full conversion (d'oh!)

 

[Brew_Meister_General]

no, Im not measuring with a refractometer, im using a hydrometer. Sorry, i forgot got to mention my OG was 1.073 which I think is not very high

My best guess is was also that you under pitched the yeast, I imagine that they have become overwhelmed by the higher levels of alcohol or simply 'given up'.

1.073 is pretty high and so somewhere between 1.5-1.75 packets would be have been more ideal depending on your volume. I'd say the English Ale yeast is a favourable choice, I'm currently using one with my milk stout!

 

[MegaMash]

No, Ive never used amylase before, thats why I was unsure whether to use it or not. Not sure how to stop it.

I made a starter from 1 tube of WL007 which im not sure was enough. I orginally started with 77 Litres of 1.073 OG. Then added 4*11g of US05 which sent it to 1.042 within 3/4days. The starter started at 1.070 and was around 3 days old when pitched so thinking it would have been at low FG when it went into the main batch.

I think it was pointless adding the 2nd yeast as there were no fermentables left in the beer.

Ive crashed it today then plan to keg it up in a few days.

 

[Queequeg]

Yeah when you repitch you gets nasty flavours, you basically have to wait another 4 weeks age the yeasty flavours.

 

[MegaMash]

Does the beer need to sit on the yeast to lose them flavours or will it go after 4 weeks in a keg?

 

[Brew_Meister_General]

I made a starter from 1 tube of WL007 which im not sure was enough. I orginally started with 77 Litres of 1.073 OG. Then added 4*11g of US05 which sent it to 1.042 within 3/4days. The starter started at 1.070 and was around 3 days old when pitched so thinking it would have been at low FG when it went into the main batch.

Wait, what, you made a starter with an OG of 1.070?

Worst case scenario you can add always add water if you think its too sweet and rich. Additionally, if you prime it with sugar it will increase the alcohol but not the gravity.

 

[MegaMash]

Ye, starter was 1.070

 

[Queequeg]

Its yeast in suspension that gives it that twang. Mine went in the bottle but if I were kegging I would leave the yeast to do it thing for a couple of weeks then crash and keg

 

[MegaMash]

I'm not that patient! The next brew is waiting to go on. I'll let you know If the flavour is still there after crashing.

Is there anything wrong in making a 2L starter at 1.070?

 

[LLBeanJ]

Is there anything wrong in making a 2L starter at 1.070?

1.070 is hard on the yeast. The point of the starter is to wake up the yeast and multiply the cell count, while not stressing them out in the process. The ideal OG for starter wort is 1.040. As was mentioned earlier, you can start with higher OG wort and dilute as needed with water to bring it down to 1.040-ish, then pitch your yeast.

 

[MegaMash]

Ok, but I didn't make a starter when I 1st pitched with dry yeast into the original wort with 1.073 OG. So not sure how it's different. I now know that everyone makes starters at 1.040.

Is it therefore wrong to be pitching dry yeast into any beer over 1.040 without making a starter?