Sg Contribution From Lactose

[WarmBeer]

Hi,

I'm brewing my first attempt at a Porter, a kit+lots-o-bits. It has been in the fermenter for 2 weeks, and SG has steadied out at 1030 (from an OG of 1057)

Now normally I would be convinced I've got a stuck fermentation, and would be guaranteeing bottle bombs if I was to bottle at 30 gravity points, however I used 500gm of Lactose in the wort.

I know Lactose is non-fermentable, but unsure how many gravity points a half kilo is going to contribute to a 20 lt batch.

Recipe details:

• Can of Cascade Choc Mahogany Porter
• 300g Choc grain
• 200g Crystal grain
• 150g Malted barley
• 500g DDME
• 500g LDME
• Fermented at 16-18 deg C with S-04 (rehydrated before pitching)

Maybe somebody out there who has previously used Lactose, or has a copy of Beersmith can work out the expected FG.

Cheers,

Brett

 

[jonocarroll]

Just in case you're getting caught out where I did recently - are you using a hydrometer or a refractometer?

By the looks of this recipe, I might expect a reasonably high FG, but would need to run it through beersmith to confirm. Perhaps someone who knows more about this can better answer this.

 

[Adamt]

Bump up the temperature and rouse as I doubt it is done, maybe 1.015-1.020 would be finished.

 

[drsmurto]

Hi,

I'm brewing my first attempt at a Porter, a kit+lots-o-bits. It has been in the fermenter for 2 weeks, and SG has steadied out at 1030 (from an OG of 1057)

Now normally I would be convinced I've got a stuck fermentation, and would be guaranteeing bottle bombs if I was to bottle at 30 gravity points, however I used 500gm of Lactose in the wort.

I know Lactose is non-fermentable, but unsure how many gravity points a half kilo is going to contribute to a 20 lt batch.

Recipe details:

• Can of Cascade Choc Mahogany Porter
• 300g Choc grain
• 200g Crystal grain
• 150g Malted barley
• 500g DDME
• 500g LDME
• Fermented at 16-18 deg C with S-04 (rehydrated before pitching)

Maybe somebody out there who has previously used Lactose, or has a copy of Beersmith can work out the expected FG.

Cheers,

Brett

150g of malted barley? Did you mash this? If not, you will have some starches in there.

I suspect you have a stuck ferment.

Agree with Adamt - crank up the temps to 20C and give it a good swirl to rouse the yeast.

Lacotse wont add that many points to your beer.

Back in my kit days i used 250g of lactose in a side by side test (ginger beers) and final gravity was 0.001 difference.

 

[WarmBeer]

Ooops, sorry Doc, I meant "roasted", not "malted". "Malted barley" would cover just about every grain we brew with. That's what I get for posting before my second coffee of the morning

I also suspect a stuck ferment, so going to give the fermenter a good old shake tonight. I'll bring up the temperature a couple of degrees, although with another 43 deg stinker predicted for here on the weekend, I'm going to want to be mindful of not letting it creep up too much.

I'll give it another week, and if still not happy, I'll rack to secondary, scoop out some slurry from my primary, and get that started back up in some fresh 1040 wort before repitching.

Cheers,

Brett

 

[drsmurto]

Ooops, sorry Doc, I meant "roasted", not "malted". "Malted barley" would cover just about every grain we brew with. That's what I get for posting before my second coffee of the morning

I also suspect a stuck ferment, so going to give the fermenter a good old shake tonight. I'll bring up the temperature a couple of degrees, although with another 43 deg stinker predicted for here on the weekend, I'm going to want to be mindful of not letting it creep up too much.

I'll give it another week, and if still not happy, I'll rack to secondary, scoop out some slurry from my primary, and get that started back up in some fresh 1040 wort before repitching.

Cheers,

Brett

You might find that simply by racking you rouse the yeast enough for it to kick off and finsih the job but warm it up for a few days and see how you go.

 

[buttersd70]

I work it out to approximately 1020. So agree that it is stuck. I agree with DrS, rack it now, that should kick it off.

 

[MHB]

Just using the back of am envelope, I get 0.011 points of SG added by the Lactose.

0.5 Kg in 20 L is 0.025 X 100 to give percent %W/V or Plato = 2.5
Plato to SG = ((P X 4) + 1)/1000 = 0.011 (roughly)

Plato is very handy

MHB

 

[WarmBeer]

I'm resurrecting this thread cause the beer in question is still stuck at 1030 after the following:
- Left it in primary for a couple more days at a higher temperature, after giving the fermenter a good shake
- Racked to secondary 2 days ago
So in total we've had not as much as a single gravity point of movement in the last week, I'd say we're stuck!

I'm taking the step of making a 400ml starter from a couple of spoonfuls of the slurry I gathered from the bottom of the primary. Going to give this 24 hours to (hopefully) come to full krausen, then throw this in the secondary cube.

How much of this starter do you think I should throw in? The whole lot, or just a cup? Maybe less? Anybody with any experience with these got an opinion on this?

Or am I possible better, albeit poorer, getting a fresh packet of S-04 from the LHBS?

I hope this beer's worth the hassles

Cheers,

Brett

 

[WarmBeer]

...bump

So, no opinions at all?

Oh well, unto the breach I go my friends.

Going to pitch all 400ml into the cube tonight when I get home. Wish me well

Brett

 

[buttersd70]

No point imo pitching fresh yeast, unless your starter is dead. If that shows signs of life, then use it. Pitch it, keep it at 20-22C for 48 hours, and if no further movement beyond that, consider it done, regardless of the high FG.....adn if thats the case, bottle in PET, and check one in 4-5 days to make sure it hasn't kicked off.

 

[WarmBeer]

No point imo pitching fresh yeast, unless your starter is dead. If that shows signs of life, then use it. Pitch it, keep it at 20-22C for 48 hours, and if no further movement beyond that, consider it done, regardless of the high FG.....adn if thats the case, bottle in PET, and check one in 4-5 days to make sure it hasn't kicked off.

Starter is good to go, fermenting away nicely down from1040 to 1016 within 24 hours.

Going to chuck the whole lot in the cube with obstinate beer tonight.

Will fill people in on the progress in a cuppla days

 

[buttersd70]

Starter is good to go, fermenting away nicely down from1040 to 1016 within 24 hours.

Going to chuck the whole lot in the cube with obstinate beer tonight.

Will fill people in on the progress in a cuppla days

<insert Mr Burns finger steeple-ing, with relevant catchphrase, here.>

 

[kenlock]

<insert Mr Burns finger steeple-ing, with relevant catchphrase, here.>

Excellent!

 

[buttersd70]

:lol: