Brewer's Friend Lactose Calculation

[Virginia_Ranger]

I have two brews right now one using WLP007 and one using RVA Hoptopper both with about a pound of lactose in them each.

NEIPA
Yeast: RVA Hoptopper (200 Billion Cell Count, 3 weeks from manufacture date), well oxygenated

4.5 Gallon (in fermenter) blended batch
Half mashed at 149 F
Half mashed at 152 F

O.G. 1.075 (with lactose)
Stuck at 1.035 at the moment
Brewers Friend says 1.021 should be FG

Imperial Milk Stout
Yeast: 2 Packs of WLP007 English Dry Ale (didn't have use by date until June 2020)
Took off very quickly, well oxygenated

2 Gallons in Fermenter
Reiterated Mash
First Mash at 149 F O.G. 1.057
Reiterated Mash at 156 F O.G. 1.120 (with lactose)
Stuck at 1.048
Brewers Friend says O.G. should be 1.039

Both fermented at 65 F then slowly up to 68 F after 4-5 days. Now on day 8 and getting them to 70s moving kegs around with slight rousing and still no movement.

Is this due to the lactose? Is Brewers Friend accurate when using lactose what the FG should be? Really hoping I don't need to repitch for those .010 points but just would rather pull the trigger sooner than later. Especially on the NEIPA since its more age sensitive.

 

[bucketnative]

How are you measuring specific gravity? Hydrometers are accurate when alcohol is present; while refractometers are not accurate in the presence of alcohol.

In your second brew, was the OG of what went into the fermenter 1.120?

Brewer's Friend treats lactose as a non-fermentable ingredient. Therefore, it should just be a spectator to the fermentation and not have any detrimental impact on the FG that is estimated by the BF recipe calculator. That said, the BF FG is an estimate, not an absolute.

 

[Virginia_Ranger]

So both O.G. and current S.G. were hydrometer measured at 65-70 F, degassed prior to reading. The second brew was 1.120 going into the fermenter, I underestimated the reiterated mash and part of the issue was I didn't remember to account for grain absorption on the second mash so O.G. was real high but that is also with a pound of lactose in the end of the boil.

 

[RPh_Guy]

Beer brewers tend to forget that yeast have an alcohol tolerance limit ....

White Labs lists this strain as tolerant to somewhere in the 8-12% range and your beer is in the 10-11% ABV range. It's very likely the yeast cannot ferment to a higher ABV.

 

[Virginia_Ranger]

I figured being in that range and double pitch on 2 gallon batch would be fine . I'm reading mixed things but would Champagne yeast finish it off? Also, I was planning to rack it on to some coconut either way but I am wondering if that may get it some more food.

 

[bucketnative]

Champagne yeast would probably not finish it, as wine yeast typically prefers to ferment simple sugars. What you have left is most likely the higher sugars: maltose and maltotriose and the like.

You could try a saison yeast, but that might get you too dry (diastaticus will chew down higher sugars).

 

[RPh_Guy]

I am wondering if that may get it some more food.

The yeast doen't need "more food"; it already had too much and it's being poisoned by all the alcohol it produced.

Pitching WLP099 would be what I suggest if you want the FG lower.