Gravity Readings

[Jackpott71]

Using a "Brewers best English Bitter" kit. The specs are listed as:
ABV 3.0-3.5%,
OG 1.032-1.036,
FG 1.010-1.014

At the shop where I purchased it, I asked one of the people there, who is a knowledgeable Brewer, if there was a way to raise the ABV. He told me to add more of the DME (light Amber) that came with the original kit. I purchased a 3 pound bag, and added 1 pound of that to what came in the kit. He said this should add about .009 to the gravity readings. On brew day, I took an original gravity reading of 1.042. After eight days in the fermenter, The gravity reading is now 1.018. I had planned to leave it in the fermenter for a total of two weeks before bottling. However, I'm surprised at how low the current gravity reading is. Calculations would tell me this puts the ABV at about 3.15.

What did I do wrong?

 

[JustLooking]

What did I do wrong?

You bought a kit that was labeled as a Best Bitter that was actually an Ordinary Bitter. Then you tried to make it into a Best Bitter by disproportionately changing the ingredients.

I'd guess that pitch rate and fermentation temperatures were not even on your radar and you have a stalled fermentation. Look into these things before you brew again, but for now give it a gentle swirl to see if you can get the yeast to do a little more work, but it's probably as low as it will go.

 

[giraffe]

That all looks as expected. You got the additional 1.009 gravity by adding the dme, and 1.004 to the final, which looks around the expected 70% attenuation. It may drop another 1.001 or so. Or it can be measuring error.

A 1.040 beer will be done fermenting in 8 days. You can leave it for the full 14 to make sure the yeast cleans up any assorted off compounds if you want. Its probably completely done.

 

[Jackpott71]

Thankd

 

[JustLooking]

[...] looks around the expected 70% attenuation.

1.042 to 1.018 is 57% attenuation by my math.





What?????
VVVVVVVV

 

[giraffe]

Im assuming his measuring is only accurate to 1.002. And he used amber dme, which isnt that fermentable.

 

[feinbera]

Im assuming his measuring is only accurate to 1.002.

Even if he were off low on the OG and high on the FG, and actually went 1.044 to 1.016, that's still only 63% apparent attenuation.

Jackpott71, I'd suspect that the yeast still have a little more work left in 'em, with the proper encouragement. Try raising the temperature of the beer to the low 70's, and give your fermenter a good shake-and-swirl once or twice a day to rouse the yeast. I bet you'll knock off a handful of points over four or five days.

Quick edit, some ways to help avoid getting a stuck fermentation on your next batch:

• Don't let the beer get too cool (varies by yeast strain, but low 60's for most ale yeasts) during active fermentation, or let the temperature fluctuate up and down too much
• Aerate - some folks use pure O2, a lot of folks do just fine just shaking the carboy or stirring the platic bucket with a paint stirrer
• Rehydrate if you're using dry yeast, make a starter if you're using liquid
• Probably other extract-brewing-specific things, but I jumped to all-grain before I started paying super-close attention to attenuation, so, I can't tell you what they are :-\

 

[Jackpott71]

Thanks for everything here, it's all very helpful