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Getting the numbers right

Post #1 made 14 years ago
by Aces high
So to give you a bit of background, I've done about 15 to 20 BIAB's, mainly double batches. Previously i've been using recipes from other people, with really good success. Recently ive gone back to try and learn the basics, so i've started doing some SMASH brews or just single hops with a fairly basic grain bill. Ive got things pretty sussed with my pot and pretty much always hit my numbers.

2 weeks ago I did this recipe below, very basic and easy. I hit my 66 degree temp spot on, but my OG finished up at 1.043 instead of 1050. I just figured I may have measured something out incorrectly, but now the batch has almost finished fermenting its down to 1.008 instead of the planned 1.013. Can anyone tell me what would have caused both OG & FG to drop?
Will this mean that its a fairly dry beer with no body?

Smasha2
American Pale Ale

Recipe Specs
----------------
Batch Size (L): 43.2
Total Grain (kg): 9.781
Total Hops (g): 138.00
Original Gravity (OG): 1.050 (°P): 12.4
Final Gravity (FG): 1.013 (°P): 3.3
Alcohol by Volume (ABV): 4.91 %
Colour (SRM): 4.8 (EBC): 9.5
Bitterness (IBU): 34.9 (Average)
Brewhouse Efficiency (%): 70
Boil Time (Minutes): 60

Grain Bill
----------------
9.390 kg Pale Ale Malt (96%)
0.391 kg Carapils (Dextrine) (4%)

Hop Bill
----------------
68.0 g B Saaz Pellet (6.8% Alpha) @ 60 Minutes (Boil) (1.6 g/L)
40.0 g B Saaz Pellet (6.8% Alpha) @ 10 Minutes (Boil) (0.9 g/L)
30.0 g B Saaz Pellet (6.8% Alpha) @ 0 Minutes (Boil) (0.7 g/L)

Misc Bill
----------------

Single step Infusion at 66°C for 60 Minutes.
Fermented at 17°C with Safale US-05
Last edited by Aces high on 06 Feb 2012, 17:57, edited 3 times in total.

Post #2 made 14 years ago
by joshua
Good Day, Just a question...What size is you kettle? The low original gravity may be due to the grain being packed and not free to convert.
Honest Officer, I swear to Drunk, I am Not God.
    • SVA Brewer With Over 100 Brews From United States of America

Post #3 made 14 years ago
by Aces high
joshua wrote:Good Day, Just a question...What size is you kettle? The low original gravity may be due to the grain being packed and not free to convert.
No, theres no fear of that, its a UK 25 gallon kettle (114L). Double batches are no problems, triples are potentially doable
Last edited by Aces high on 06 Feb 2012, 20:56, edited 3 times in total.

Post #4 made 14 years ago
by joshua
Aces High, The thing I wondered was with 42L water, 10KG grain will need 22L of volume for a total of 67L of volume. Many times if the mash is not mixed/stirred the O.G. can end up lower than desired.
Your kettle had Lot's of space for the grains so I think the mash was ok.
Question... Does you hydrometer resd 1.0000 in 23C water, I have had a Hydrometer that went bad due to a tiny crack in the base, and read low.
Honest Officer, I swear to Drunk, I am Not God.
    • SVA Brewer With Over 100 Brews From United States of America

Post #5 made 14 years ago
by thughes
Hydrometer and/or thermometer out of calibration? (Couple of degrees low on the mash temp will give the results you have described.)

---Todd
WWBBD?
    • SVA Brewer With Over 100 Brews From United States of America

Post #6 made 14 years ago
by Aces high
joshua wrote:Aces High, The thing I wondered was with 42L water, 10KG grain will need 22L of volume for a total of 67L of volume. Many times if the mash is not mixed/stirred the O.G. can end up lower than desired.
Your kettle had Lot's of space for the grains so I think the mash was ok.
Question... Does you hydrometer resd 1.0000 in 23C water, I have had a Hydrometer that went bad due to a tiny crack in the base, and read low.
The hydro seems fine, although I haven't check it in water, I did another batch on the weekend and it came up to 1050 exactly how it was meant to. So its just this one brew that has both a low OG & FG.

I actually start with 67L of water + the 10kg of grain to get a total of 40L into the kegs (plus a couple of bottles). Total mash volume is 74L acording to the calculator. The mash was stirred well and I hit 66 degrees for that mash, so i can discount those things. The addition of carapils should keep the FG up to about 1013 as predicted.
Last edited by Aces high on 06 Feb 2012, 21:21, edited 3 times in total.

Post #7 made 14 years ago
by Aces high
thughes wrote:Hydrometer and/or thermometer out of calibration? (Couple of degrees low on the mash temp will give the results you have described.)

---Todd
Maybe it was the mash temp, I might have to recheck that thermometer.
Last edited by Aces high on 06 Feb 2012, 21:23, edited 3 times in total.

Post #8 made 14 years ago
by stux
FG being lower when OG is lower is normal. There are simply less non-fermentable because there is less extract.

So your problem was basically an efficiency problem.

Do you mill your own grain? Buy by the batch? Etc?

Could've been old/stale or moist grain. Could've been not milled fine enough
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #9 made 14 years ago
by PistolPatch
I wouldn't be worried about this for a second Ace ;),

If it happens again, be on alert but not alarmed :). If it happens three times in a row, then it's worth slowing down and having a good think.

There are way too many variables that can occur on a single brew. The most common one is simply incorrectly weighed grain but the list is endless.

Brew on!
PP
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Post #10 made 14 years ago
by Aces high
PistolPatch wrote:I wouldn't be worried about this for a second Ace ;),

If it happens again, be on alert but not alarmed :). If it happens three times in a row, then it's worth slowing down and having a good think.

There are way too many variables that can occur on a single brew. The most common one is simply incorrectly weighed grain but the list is endless.

Brew on!
PP
Kegged this batch on the weekend, it tastes good, just a pretty basic easy drinking summer pale ale.

Did another brew last weekend (slighly more complicated) and hit all the numbers spot on again. Its funny that i missed the numbers on the easiest brew i've ever tried.
I've started fermenting the new brew in 2 x 20L jerry cans side by side. One with Us-05 (which ive mainly been using) and one with wyeast 1272 so I can get a better idea of different yeast profiles
Last edited by Aces high on 13 Feb 2012, 19:20, edited 3 times in total.
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