Question about lost sweetness in a tropical stout?

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Ezian

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Hi All,

Made a tropical stout which i tasted two weeks after bottling and it was very tasty with a lot of residual sweetness (verging on too much). Anyway, two weeks more and tried it again and all the sweetness was gone?? I measured the FG again and it hadnt changed from when it was bottled (1013). Disappointing as the beer was so tasty with that sweetness.

Any ideas why?
 

MHB

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Well the obvious is Diacetyl, yeast can sometimes metabolise excess VDK's especially in bottling where you are kicking off the ferment again with your priming. In fact adding some working beer is a standard fix for DA issues, usually when it’s a lot more obvious than yours sounds to be.

There are a few other related processes and rather than just DA it could be a bit of DA and a lot of smaller parts adding up to the whole. Virtually all of them come down to yeast management.
If you aren’t happy with the answer a few more details on your recipe and process might help.
There are also a few simple ways to check for VDK before you bottle. Here is one. There are others only a Google away, if you are making big beers, or are getting certain off flavours, it’s a step well worth adding to your brewing process.

Mark
 

Naboo

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Was it fully carbonated when you had your fist taste?
 

Ezian

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Well the obvious is Diacetyl, yeast can sometimes metabolise excess VDK's especially in bottling where you are kicking off the ferment again with your priming. In fact adding some working beer is a standard fix for DA issues, usually when it’s a lot more obvious than yours sounds to be.

There are a few other related processes and rather than just DA it could be a bit of DA and a lot of smaller parts adding up to the whole. Virtually all of them come down to yeast management.
If you aren’t happy with the answer a few more details on your recipe and process might help.
There are also a few simple ways to check for VDK before you bottle. Here is one. There are others only a Google away, if you are making big beers, or are getting certain off flavours, it’s a step well worth adding to your brewing process.

Mark
Hi Mark,

Apologies, i'm still relatively new at brewing!

More details;
S-23 lager yeast. Chilled to around 18° and then left to chill further overnight before dry pitching at 16°. OG was 1070. I had added additional sugar into the wort, aprox 4.5% of the bill. Not sure how important that is? Fermented at around 12-14 degrees for 2 weeks. Bottled at FG 1013 in PET / Fliptop long necks with two carbonation drops each.

I think im one of those people that struggle to smell the DA smell unfortunately. Or i havent had a really DA affected beer ive tasted yet. I need to get one of the Siebel tests and get a good whiff so i know what im looking for.
 

MHB

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With the extra info I'm still inclined toward yeast management issues, probably some VDK and some esters.
In a 23L batch at 1.070 you should have pitches 2 packets of S-23 and it should be fermented cooler than 18oC (have a look at the sheet). Worth reading up on a yeast before you use it.
You got good attenuation (probably being too warm helped with that)
Mark
 

An Ankoù

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The fact remains that the first bottle was sweet and the second wasn't, with no change to the FG.
I reckon the first bottle, while seemingly fully carbonated, had only used up about half (or so) of the priming sugar. Sucrose has a very low flavour threshold anyway, so the half a teaspoonful in a bottle would certainly make a difference. However, it's not enough to make a discernable difference on the hydrometer, especially if you tried to measure the OG while the beer was still fizzy.
I'll bet you got more of a "pop" when you opened the later bottles than you did with the first.
If you like a bit of sweetness, you could add lactose to the brew as this isn't fermented by ale yeast. It's not very sweet, though compared with sucrose so you'll need to look up the additions.
 

Ezian

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With the extra info I'm still inclined toward yeast management issues, probably some VDK and some esters.
In a 23L batch at 1.070 you should have pitches 2 packets of S-23 and it should be fermented cooler than 18oC (have a look at the sheet). Worth reading up on a yeast before you use it.
You got good attenuation (probably being too warm helped with that)
Mark
Im doing 10L batches on the stovetop, so 1 full pack of S-23. Yeah 18 not ideal at all, i just dont have any real way to get it down any lower without just adding ice, which i dont want to do :(
 
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Ezian

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The fact remains that the first bottle was sweet and the second wasn't, with no change to the FG.
I reckon the first bottle, while seemingly fully carbonated, had only used up about half (or so) of the priming sugar. Sucrose has a very low flavour threshold anyway, so the half a teaspoonful in a bottle would certainly make a difference. However, it's not enough to make a discernable difference on the hydrometer, especially if you tried to measure the OG while the beer was still fizzy.
I'll bet you got more of a "pop" when you opened the later bottles than you did with the first.
If you like a bit of sweetness, you could add lactose to the brew as this isn't fermented by ale yeast. It's not very sweet, though compared with sucrose so you'll need to look up the additions.
Wasnt just the first bottle, the first 4 bottles all drunk on the same weekend, hahaha. FG readings were accurate, first one before bottling and second one was after letting beer go completely flat.

Im already geared up to make the same again. Think i'll do exactly the same thing and see if i get the same results, maybe get a few other people to taste at the 2 and 4 week mark and see if they agree, especially seeing im not good at tasting Diacetyl.

I do have some spare lactose which i'll throw in next time if this run turns out the same way.
 

MHB

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Mate you know how important temperature control is!
I think investing in a second hand bar fridge and a temp controller add a small fan and that’s all you need.
I would rank temperature control just after hygiene and before going all grain in order of importance as steps on the quest for great beer, even more important if you want to make Lagers well.
Mark

PS anything under 6 weeks is infanticide with stouts, usually at their best after 6-12 months.. Patience.
M
 

Ezian

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Mate you know how important temperature control is!
I think investing in a second hand bar fridge and a temp controller add a small fan and that’s all you need.
I would rank temperature control just after hygiene and before going all grain in order of importance as steps on the quest for great beer, even more important if you want to make Lagers well.
Mark

PS anything under 6 weeks is infanticide with stouts, usually at their best after 6-12 months.. Patience.
M
Yeah sadly I know how important temp control is. Unfortunately living in a small unit doesn't allow much in the way of 2nd fridges etc. Even if i had power in the garage it would be workable, but there's nothing there (short of somehow cutting into the common lights circuit).

Space is also the reason i brew 10L batches, its manageable on the stovetop. Takes a long time to get it boiling! Also makes it tough to hold on to beer for 6 months when you only have 9L ending up in bottles.

The joys of living in Sydney (and being poor).
 
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