2 stuck FG's

[SoupNazi]

Ive been doing AG brews for the past 15 batches, and all have been close their projected FGs as well as tasted great. Then comes this past weekend when I checked my gravities (Six - 5 Gallon batches :rockin, and found 2 that were not at all where I wanted them to be.


Brew #1- Rochefort 8 Clone

10 lbs 8.0 oz Pilsner (2 Row) Bel (2.0 SRM)
1 lbs 8.0 oz Caramunich Malt (56.0 SRM)
8.0 oz Corn, Flaked (1.3 SRM)
8.0 oz Special B Malt (180.0 SRM)
1.6 oz Carafa I (337.0 SRM)
8.0 oz Sugar, Table (Sucrose) (1.0 SRM)
1 lbs 11.2 oz Candi Sugar, Dark (125.0 SRM)

1.0 pkg Belgian Abbey II (Wyeast Labs #1762) - 1.5L Starter

Mash:
Protein Rest- 142* for 30 min
Sacc- 155* for 30 min
Mash Out- 168* for 10 min

OG = 1.078
FG = 1.020 fermed @ 70* - 6 weeks in Primary (after rousing attempts)
Shooting for a FG < 1.012.





Brew #2 - Choconana

8 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 2 51.5 %
1 lbs Munich Malt (9.0 SRM) Grain 3 6.4 %
1 lbs Oats, Flaked (1.0 SRM) Grain 4 6.4 %
1 lbs Patagonia Chocolate Malt (350.0 SRM) Grain 5 6.4 %
12.0 oz Black (Patent) Malt (500.0 SRM) Grain 6 4.8 %
12.0 oz Caramel/Crystal Malt - 60L (60.0 SRM) Grain 7 4.8 %
8.0 oz Chocolate Malt (350.0 SRM) Grain 8 3.2 %
8.0 oz Roasted Barley (300.0 SRM) Grain 9 3.2 %
8.0 oz Special Roast (50.0 SRM)

0.75 oz Cascade [9.10 %] - Boil 60.0 min Hop 11 20.3 IBUs
1.05 Items Whirlfloc Tablet (Boil 15.0 mins) Fining 12 -
1.05 tsp Yeast Nutrient (Boil 12.0 mins) Other 13 -
1 lbs Milk Sugar (Lactose) [Boil for 10 min](0.0 SRM) Sugar 14 6.4 %
0.60 oz Hallertauer Hersbrucker [4.00 %] - Boil 5.0 min Hop 15 1.4 IBUs
0.40 oz Hallertauer [6.90 %] - Boil 5.0 min Hop 16 1.6 IBUs
4.00 oz Semi-Sweet Chocolate (Boil 5.0 mins) Other 17 -
4.00 oz Unsweetened Cocoa (Boil 5.0 mins) Other 18 -
8.3 oz Brown Sugar, Dark [Boil for 5 min](50.0 SRM) Sugar 19 3.4 %
Still to be dry-hopped with bananas.

2.0 pkg Weihenstephan Weizen (Wyeast Labs #3068) [124.21 ml]

Mashed @ 155* for 60 min
Mash-Out @ 168 for 10 min

OG = 1.080
FG = 1.038 @ 3 weeks fermed @ 70*F
Shooting for a FG ~1.024





I have a bottle of Amalase Enzyme (Alpha Amalase I assume). I am considering using it on both batches, but I have no idea on how much to achieve my desired FG. Not really looking to dry out my sweet stout, but would like the belgian to come down a bit more. The container states: "1 tsp per 5 gal".


Anybody have experience with this and has an estimate of how many gravity points 1 tsp with drop these puppies?

And if I use some, does the yeast cake need to be present to do its magic, or can I rack off it and wash/reuse?

Much Thanks HBT.

 

[BlueGrot]

Your rochefort clone has attenuated 74.4%, well within the yeast's reference of 73-77%. An FG of >1.012 would have meant an attenuation of 84%. Quite off the reference values. It's probably a % the yeast might do occasionally, but for this beer the fermentation is complete, provided the SG has stopped sinking.

An apparant attenuation of 52% for your sweet stout seems low, but you did mash at 68.33c. My uneducated guess is that both of these fermentations are complete.

Edit: Though I'd be more worried about the stout than the rochefort. Grenades are not fun.

 

[COLObrewer]

The rochefort is done, you might raise the temp on the sweet stout a little, give it a swirl and wait another week or so but with the amount of adjuncts in there it could be close to FG as well. Have you dry bananaed it yet?

Edit: NM I see that you haven't dry bananaed it yet, i would raise the temp some, swirl, add bananas then wait.

 

[cfonnes]

I am curious to see if you get flavors of plum in your Rochefort 8.

I had one finish a little high and liked it more than the ones that finished lower due to the plum taste.

 

[SoupNazi]

Thanks for the replies.

I see nobody mentioned the Amalase enzyme. I think im going to add a tiny amount and see if I can squeeze off a couple more points on each brew. I am aware of the risks associated with bottle bombs after adding AA- So I plan to keg and condition both these brews to be on the safe side.

 

[Yooper]

Mashing at 155 guarantees a higher FG. If you want a drier beer, having a lower FG, mash much lower. For a triple, I've mashed at 147 and 149 for a higher attenuation (and using little to no crystal malt).

In the second beer, remember that a pound of lactose will increase the FG by about .009 right there. With mashing high, the lactose, the less fermentable ingredients, etc, and an OG of 1.080, I'd definitely expect a high FG.

I would NOT use amylase to drop the FG as the beer is simply done.

 

[SoupNazi]

Mashing at 155 guarantees a higher FG. If you want a drier beer, having a lower FG, mash much lower. For a triple, I've mashed at 147 and 149 for a higher attenuation (and using little to no crystal malt).

In the second beer, remember that a pound of lactose will increase the FG by about .009 right there. With mashing high, the lactose, the less fermentable ingredients, etc, and an OG of 1.080, I'd definitely expect a high FG.

I would NOT use amylase to drop the FG as the beer is simply done.

Thanks Yoop.

Looks like I'll chalk this one up as a learning experience.

Or I could throw some 3711...

 

[BlueGrot]

That will only help if what stopped the FG is the attenuation % of the yeast. If there's no more fermentables, there's no more fermentables. I doubt it would have any effect, and would in the best case completely shift the profile of two beers that are most likely delicious.

 

[SoupNazi]

UPDATE:


The Rochefort 8 clone was left alone and is ageing in a keg.


I ended up racking the Choconana on 1.5 lbs of peeled, frozen, thawed & mushed bananas as well as 1 tsp of Amalase Enzyme dissolved in water and let it sit for 2 weeks while on vacation. Obvious signs of another fermentation were present before I left, so hopes were high.

Pulled a sample today and was happy to see a gravity of 1.020! Dropped 18 points in 2 weeks and is sitting @ 7.9% ABV. The taste was also fantastic! The appearance of rich black oil with dominant chocolate flavors and subtle banana notes. Kind of what I was aiming for. Just hope the gravity stays consistent and does not thin out anymore.