What is special about SG=1.02?

[bonzombiekitty]

Some have talked about the curse of 1.02, particularly when it comes to extract recipes. I myself have experienced that curse many a time. Every time I get a stuck fermentation, it's ALWAYS at SG=1.02. I understand that extract has a certain level of unfermentables in it, but it seemed that no matter how much extract I used, I'd ALWAYS get stuck at 1.02. Whether I used enough extract to start off at 1.05 or 1.08 - it'd go down to 1.02 and stop. Going by posts on this site, it seems that a lot of people get stuck at the same point.

Does anyone know what is so special about 1.02?

This isn't as much of an issue for me now as I have moved to all-grain and have been better about pitching a lot of yeast. I'm just curious if there's a reason that 1.02 seems to be the magic number. Or am I just crazy?

 

[slicksmix]

I get it sometimes. It drives me crazy. I too would like to know a. Why it happens and b. How to prevent it.

 

[Bacon]

its happened to my only once, but it may have something to do with lme getting burned at the bottom of the pot when you add it? Although, it's also probably not a coincidence that the only time it happened, it was with yeast that I got from a kit in the mail as opposed to yeast I got from my LHBS.

 

[rudu81]

I too would like to know a. Why it happens and b. How to prevent it.

it may have something to do with lme getting burned at the bottom of the pot when you add it?

I've gotten it a few times, give or take based upon where I've read my hydrometer. Bacon is right in that it does depend on the scorching of the LME or DME on the bottom of the kettle. Some instructions have you take the kettle off heat for 5 min or so and then add it. Also, I believe that some crystallization/scorching can occur during the manufacturing process. You can also search for 1.020 curse or similar to get more answers.

Hope this answers your questions!

 

[McGarnigle]

Some have talked about the curse of 1.02, particularly when it comes to extract recipes. I myself have experienced that curse many a time. Every time I get a stuck fermentation, it's ALWAYS at SG=1.02. I understand that extract has a certain level of unfermentables in it, but it seemed that no matter how much extract I used, I'd ALWAYS get stuck at 1.02. Whether I used enough extract to start off at 1.05 or 1.08 - it'd go down to 1.02 and stop. Going by posts on this site, it seems that a lot of people get stuck at the same point.

That's interesting. I always thought it was that many extract kits are in the 1045-1050 range, and 1.020 represents 55-60% attenuation. in other words, if you started with a higher OG, you'd get stuck higher. Maybe there's some minimum level of unfermentables that doesn't factor up with gravity.

 

[Calder]

I use a lot of LME. Do a lot of partial mashes, and a number of extract (+steeping grains).

Looking at my records over the last 160 batches that I have done, I have never had one finish at (or above) 1.020. A lot of them were brewed before I started partial mashes.

I prefer drier beers, so I use more aggressive yeasts (Essex, PacMan, WLP550, etc). I rarely get less than 80% attenuation, and that number is calculated after I remove the effect of any simple sugars (corn or table sugar, honey, etc) from the measured OG.

I use Briess LME exclusively these days, but have used lots of different ones in the past, even used the notorious Laagerlander as part of the ingredient list before (not 100%).

I do not believe it is an extract 'thing'. I think it is more likely poor yeast selection and practices used by newer brewers; poor aeration, no starter, no-name or cheap yeast, racking before finished, etc.