Adding dex /ldme to an all grain stout

[matt77]

I've done an all-grain stout. Pale malt, flaked barley and roast barley (66%, 20%, 10%)
OG 1.042 mashed around 68°c
.
So probably won't finish real low.
But i like my beers nearly 6% alc.
If i add 1kg dex (or 500 dex 500 ldm) will it ruin it? Was going for a guinnesss clone and have 800ml soured wort to boil and add today...
Any thoughts

 

[MHB]

No it wont ruin it, add away.
Just one point, if you don't give the volume of wort there is no way to judge the effect 1kg of dex (or whatever) will have.
Say it pulls up at around 1.014 you would be looking at ~3.7% ABV, to get to 6% you need to add 2.27% more alcohol. That requires adding 17 points of fully fermentable sugar to take the OG to ~1.060.
Put it in Plato its 4.25oP or 42.5g/L so in a 23L ferment you would need 977.5g of say Sucrose or Maltose.
Dextrose is only 91% fermentable so it would be 1074g (1kg is going to be pretty dam close).
Smaller batch you need less, bigger batch more. If you went with LDME its only ~63% fermentable and will add to both the OG and the FG.
Mark

 

[matt77]

Thanks
Yep 22 litre batch
500dex 500 malt
I just work on 10g sugar per 100ml water. 2kg per 20 litre =1.040
Or 1kg sugar to 20 litre =1.020

Didn't consider malt would up fg a little.
Thanks

I went 29g columbus (16%) recipe was 19g so I've probably got a bit of room to add sweetness

 

[MaggieO]

When I make barley wine or imperial stouts I aim to get a wort of 1.055 or so and make up the difference with extract. Something that strong your going to age for six months anyway you never notice the extract

 

[matt77]

When I make barley wine or imperial stouts I aim to get a wort of 1.055 or so and make up the difference with extract. Something that strong your going to age for six months anyway you never notice the extract

It'll be lucky to get 2 months.
Was going to keg it .

 

[Grmblz]

Typically a RIS is 10% + and BW's a little less, from personal experience I would advise against kegging such brews, it can get very messy very quickly, and I'm not talking about the beer.

 

[The Mack]

Kegging a big beer is a wonderful thing if you have the patience, just had a 9L keg blow (Saturday night) of RIS that was ~ 18 months old, was absolutely delicious. I'd only ever have <3 glasses of it at a time but it only made it that long because I've always had other beers on tap as well.

 

[Grmblz]

Totally agree ^ 7yrs being my best effort, lived overseas for an unplanned extended period, and had it in storage, then opened it for a party, hence my reference to messy

 

[matt77]

Aiming for 6% i wouldn't call that big.
Most of my brews have been about that and they're all gone in 2 months.

I had a dark ale in pet bottles for 7 years. Forgot them at the folks place.
Tasted like nectar...

 

[JDW81]

.
Dextrose is only 91% fermentable so it would be 1074g (1kg is going to be pretty dam close).

Slightly OT.

Why is dextrose only 91% fermentable? It‘s the D-isomer of glucose, which I was always under the impression was fully fermentable by brewing yeasts.

JD

 

[MHB]

Glucose - Glucose is Maltose, cut maltose in half and something goes into the junction, in this case a water molecule so you actually have Dexter Rotated Glucose Mono-Hydrate.
Works out that the water is 9% of the mass of the molecule but doesn't add to the fermentable mass just goes into solution.
Mark

 

[JDW81]

That makes sense, thanks Mark.

 

[matt77]

Glucose - Glucose is Maltose, cut maltose in half and something goes into the junction, in this case a water molecule so you actually have Dexter Rotated Glucose Mono-Hydrate.
Works out that the water is 9% of the mass of the molecule but doesn't add to the fermentable mass just goes into solution.
Mark
View attachment 118352

Probably why it is reported to thin the beer slightly. It is adding water...
Roughly 100mL for every kg dex

Nice science