FG Question

[Jourdo]

Hi guys, just wondering if I have reached FG or maybe the yeast has stalled.. would love your opinions..

recipe was
1 Can Coopers Lager
1kg BE1
500g LDM
Kit yeast

Its been in the fermenter for 12 days now and the last three have shown the gravity at 1015.. I thought this was a bit high? or is it possibly done?

Thanks

 

[NewtownClown]

If we are talking 20-23 litres then sure, that's not high. Considering maltodextrin (400 grams in the BE1) is only about 30% fermentable

 

[Jourdo]

Thanks mate, I'll bottle it up tonight

 

[carniebrew]

I agree it's ready to go, but maltodextrin is actually unfermentable, by brewer's yeast anyway.

 

[manticle]

It's mostly unfermentable, not completely (around 75 % I think) but that FG looks Ok with those ingredients. A few more days will help mature it though and if you can keep it at ferment temps, will add a bit of confidence in the FG

 

[carniebrew]

I've only ever seen it referred to as non-fermentable, such as here: http://liquorcraft.com.au/afawcs0133827/CATID=0/SUBID=369/ID=5/SID=3665310/productdetails.html, here: http://www.coopers.com.au/forum?g=posts&t=337 (2nd post, from Frank, a Brewer at Coopers) and here: http://www.jimsbeerkit.co.uk/forum/viewtopic.php?f=4&t=44616 (again 2nd post)

Also the software I use (Ianh's spreadsheet) has it with a fermentability of 3 (compared to dextrose with 100). So I guess he's calling it 3% fermentable.

Now I'm just confused. Not that it matters given I don't think I've used it since about my 2nd ever brew.

EDIT: Maybe this is where Ian got the 3% from: http://www.ibrew.com.sg/Ingredients.asp
"Good for adding mouth feel, body and head retention to brews without affecting flavor. Maltodextrin is a chain between 4 and 20 dextrose units in length making it only 3% fermentable by brewer's yeast."

And Coopers definitely think it's non fermentable too: https://store.coopers.com.au/shop/product/DBS643/

Is it possible there's different types of maltodextrin?

 

[manticle]

For all intents and purposes, it can be considered unfermentable. I can't remember the exact amount but I'm pretty sure it's more than 3%. It's an academic discussion (which I'm happy to research more and happy to admit if I'm wrong) as it will generally lead to a fuller body and higher FG and is predominantly an unfermentable product.

I'll have a look and see if I can work out where I got 75% from.

 

[manticle]

Here is one thread (not an academic source I'll grant - see Pint of Lager and Tony's posts)

http://aussiehomebrewer.com/topic/12585-what-is-maltodextrin/

 

[carniebrew]

There does seem to be a massive difference of opinion out there when it comes to maltodextrin. The wikipedia entry says this towards the bottom:

Maltodextrin has no flavor and is not fermented by the yeast, so does not increase the alcohol content of the brew

I'm pretty sure I still have a bag of it lying around somewhere, might be time for an experiment...if I can find some Coopers kit yeast to waste on it.

 

[Muscovy_333]

It is a matter of refinement.
It is derived from starch and I believe can come in a range of "dextrose equivelents"
I used to use it in a range of food products in a previous life.
The stuff from China was all over the shop for purity, but the "better" suppliers could provide quality assurance and a standardised product.
So...Oils aint oils, but it is, generally speaking, a non-fermentable adjunct (with a tolerance of a few % here or there).

 

[carniebrew]

Apparently it can be derived from potato, corn, rice or wheat...and is such a highly processed product that even when made using wheat it's still gluten free.

 

[Muscovy_333]

Yep...refined.
Starch separated from protein (glutens) and partially hydrolysed to denature starch function....cant remember the chain length polymer.
= cheap by-product/filler/carrier/processing aid for the food industry

 

[slcmorro]

if I can find some Coopers kit yeast to waste on it.

I've got some