Spike Brewing 12.5 Conical Fermenter Giveaway!

Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > specific gravity question

Reply
 
LinkBack Thread Tools
Old 12-11-2009, 04:18 PM   #1
coastwx
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2009
Location: Raleigh, NC
Posts: 255
Liked 3 Times on 3 Posts
Likes Given: 3

Default specific gravity question

First of all, thanks to everyone for the great information in all these forums. I've been lurking for the last month or so, and have absorbed a lot from the experienced brewers as well as the newbies. I'm the type that jumps straight into the deep end when trying something new. Since I had an unused 5 gal water cooler my first batch was an all grain Boulder Beer Co Mojo IPA clone. I immediately followed that up with an American Ale and then a Fat Tire clone. After reading many posts here about sanatizing I became worried that my use of beer bright with well water rinse may have led to an infection of my first three batches. Although these brews are still conditioning in bottles, I've chilled samples of all and I'm stoked that two actually taste great (Mojo and Fat Tire) and the one is definitely drinkable! BeerSmith is a great tool!

On to my question. My main mistake from the first batches is the lack of robust before and after gravity measurements. I did a Stone IPA clone last weekend and did my gravity measurements this time. Post boil, pre-pitch gravity was around 1.072. The fermentation was vigorous to the extent that I blew the air lock off the carboy even though I used fermcap, so I've learned the hard way to use a blow off tube. Anyway primary fermentation has take place for 6 days now and the gravity reading yesterday (as I was cleaning up the beer splatter off the closet walls) was all the way down to 1.015. I was surprised the gravity was so low given the 15 lb of grain used and just 6 days after fermentation. Does this sound like a reasonable drop if density? Thanks in advance!

FYI, It seems I read somewhere that lower mash temp can lead to higher conversion to alcohol. My mash was suppose to be at 148 deg, it was at the start, but at the end it was a little lower around 144 deg.

__________________
coastwx is offline
 
Reply With Quote Quick reply to this message
Old 12-11-2009, 04:21 PM   #2
android
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Ames, Iowa
Posts: 3,117
Liked 37 Times on 31 Posts
Likes Given: 3

Default

what kind of yeast did you use? I wouldn't be all that surprised if it finished in 6 days. most of my beers are done within or at one week. yes, a lower mash temp definitely contributes to a more fermentable wort, so that would make sense... as long as you pitch the right amount of yeast, aerate your wort properly and allow good fermentation temps, yeast will do the bulk of primary fermentation pretty quick IMHO. and of course letting it sit on the yeast cake for another week is a solid idea.

__________________
primary: APA

ebay temp controller | thermostat temp controller
android is offline
 
Reply With Quote Quick reply to this message
Old 12-11-2009, 04:41 PM   #3
david_42
Feedback Score: 0 reviews
 
david_42's Avatar
Recipes 
 
Join Date: Oct 2005
Location: Willamina & Oak Grove, Oregon, USA
Posts: 25,651
Liked 133 Times on 126 Posts

Default

You've got 80% apparent attenuation, which is in keeping with your low mash temperature. This will reduce the malt flavors and body, but that's not too big a deal in an IPA.

__________________

Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"

"I would like to die on Mars, just not on impact." Elon Musk

david_42 is offline
 
Reply With Quote Quick reply to this message
Old 12-12-2009, 06:20 PM   #4
coastwx
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2009
Location: Raleigh, NC
Posts: 255
Liked 3 Times on 3 Posts
Likes Given: 3

Default

I thank you both. It was Nottingham yeast.

Just took another reading today and it was down to 1.012

__________________
coastwx is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Specific gravity question freeland All Grain & Partial Mash Brewing 7 11-30-2009 05:47 PM
Nothing wrong, just a question (specific gravity) oteixeira Beginners Beer Brewing Forum 10 12-14-2008 05:15 PM
specific gravity question beerman23 Beginners Beer Brewing Forum 2 08-28-2008 02:00 AM
specific gravity question ryan99 General Beer Discussion 12 02-11-2007 11:21 PM
Specific Gravity question Matt Beginners Beer Brewing Forum 1 09-23-2005 06:06 AM