Stuck at 1020: could it be the fermentables?

[garagecollective]

Hi everyone, first time post but have trawled this site for a while now.

I've now brewed three batches, using kits plus my own additions (the last one I made a hop tea, and dry hopped in the fermenter). However, with my last two batches the hydrometer readings never passed 1020. They taste fine, and I'm not too phased that the alcohol % is lower, but I do want to hit the right targets in future.

First kit: Black Rock Export Pilsner; second kit: Muntons Traditional Bitter. Both these 1020 batches have been mixed with a Copper Tun 1kg beer Enhancer (which has malt extract, dextrose and the like pre-mixed), and I wonder if that's the problem (ie there's not enough fermentables in it?)

If that's the case, I'm thinking of adding some malt extract, raw sugar, or both, to give it a bit more kick. Do you think that's the way to go? Both, or just one? And how much?

I use a temp. controlled fridge with thermostat, so temperature shouldn't be a problem. If anything I may not have stirred the cold water into the hot wert well enough before adding the yeast on the last one, so that could be it too...

Look forward to your advice!

PS you can check out my set up here: http://www.garagecollective.blogspot.co.nz/2012/03/home-brewing-start-of-obsession.html

 

[Captain Damage]

Pitch new yeast. The conventional wisdom is that (somehow) your yeast got "trained," in a sense, to only eat the simplest sugars and going dormant once they're gone rather than moving on to more complex sugars. It could have been the beer enhancer, but it's one of those things just happens from time to time with extracts.

The solution should be to add a fresh pitch of the same strain of yeast that you pitched originally, or a more attenuative strain. People often talk about repitching with champagne yeast, thinking that champagne is dry, therefore it should make the beer drier. The problem with that thinking is that champagne is dry because grape juice is almost entirely sucrose and fructose - simple sugars - which are the very sugars that have already been eaten by the yeast in your 1.020 beer.

 

[eppo]

If these are extract kits, its probably sure to the extract. I've had a few extract kits not make it below 1.020. I actually re did the double chocolate stout in all grain, got it down to 1.014, definitely a difference in sweetness, but both were very drinkable, so I wouldn't worry much.

 

[garagecollective]

Thanks guys! @Captain Damage, I take it you mean getting rid of the packet yeast that comes with the kit, and getting a better one of the same strain?

 

[Captain Damage]

No, I mean pitch a new pack of yeast after you've fermented your beer and measured your final gravity and found your beer hasn't fully attenuated. You will have to wait another week or two after the repitch to bottle.

 

[garagecollective]

Ok cool, thanks for that clarification. Would a yeast nutrient do the trick as well?

 

[Captain Damage]

No. See the thing is, the yeast you have has become adapted to eating only the simplest sugars. No type or amount of nutrient(s) will get them to change back. You need a new pitch of yeast that hasn't become "corrupted" in this way. While adding a yeast nutrient in addition to this new pitch certainly won't hurt - in fact it may replace nutrients that were depleted by the yeast from your original pitch - nutrient level is not the root of the problem.

 

[JLem]

I second the idea that the extract had low fermentability. The so-called 1.020 curse of extract beer. I doubt your yeast would have stopped fermenting complex sugars. You can add up to 20% simple sugars and still have your yeast finish fermentation just fine. Yeast will give out if the alcohol content is too high, but assuming these beers were of "normal" gravity, I doubt pitching more yeast will help.

 

[Yooper]

I second the idea that the extract had low fermentability. The so-called 1.020 curse of extract beer. I doubt your yeast would have stopped fermenting complex sugars. You can add up to 20% simple sugars and still have your yeast finish fermentation just fine. Yeast will give out if the alcohol content is too high, but assuming these beers were of "normal" gravity, I doubt pitching more yeast will help.

I've had the same thing- many of my extract beers just wouldn't go past 1.020 even with a well attenuating ale yeast.

Next time, if you're using canned kits, toss out the Cooper's or Munton's yeast that comes with it and use nottingham dry yeast. But even using nottingham might not make the FG come much lower. It will give a better tasting product, though!

1.020 is fine, if that is where the beer stays.

 

[BrewKnurd]

I heard an interesting theory from John Palmer on the whole 1.020 thing. He pointed out that not too long ago, it was pretty normal to brew "kit and kilo", where you had a can of extract and then added a couple pounds of simple sugar. In a setup like that, you would want less fermentable extract. His theory was that some extract manufacturers have never shifted their processes from when this lower fermentability was actually a good thing.

Don't know if its an accurate theory, but it makes sense as a possibility.

 

[garagecollective]

Thanks everyone. The beer tastes great, so maybe I shouldn't worry too much! But think I'll play with yeast options.

 

[AxDxMx]

I've got a couple beers currently bottle conditioning that had roughly the same problem. They tasted a little sweet, and finished at 1.020 and 1.018. For my next batches I'm switching up on yeasts, and using a couple liquid smack packs. If that doesn't do any better, maybe I'll just break down and start making starters, or take the plunge and go all grain. Glad to know I'm not the only one having these issues.