High Gravity Fermentation

[tarcrarc]

I'm brewing a barley wine and the OG came in higher than expected (1.120). Recirculating the sparge is what made the surprise on the OG. Anyway, it's been going mad for the past 48 hours--no problem. Usually, my FG comes in a little higher than I want so I have lately been in the practice of adding a small amount of simple sugar to my boils to get it down to some degree. I did not do so on this brew.

Here's my question: I'm 2 days in and all is going well. I am shooting for a FG of somewhere around 1.025-1.030. Since I tend to come in high on my FG I am thinking about adding 1 lb. or so of corn sugar to make sure it doesn't stop out too high. My concern is the fact that even if I hit 1.030 I'm at a 12% brew and if I go even lower on the FGI may end up with a brew that tastes rather alcoholic.

I see 3 options:
1. Let it go without the sugar and forget it
2. Add the sugar now
3. See where I am at when things slow way down and add sugar if I am (FG) too high.

If the answer is #3---when is it too late to add sugar where the yeast will still consume it?

Thanks

 

[ncbrewer]

I don't brew high gravity beer, but I've always found that adding sugar doesn't affect FG. The simple sugar should just ferment out completely, and the rest should not be affected, leaving the same FG... unless the additional sugar takes it beyond the yeast's alcohol tolerance or otherwise changes the fermentation dynamics. I'm interested in what others have to say about this.

 

[Calder]

I would say 1.025/1.030 would be way too sweet, for me anyway. I like to try and get down to about 1.010. 1.030 will taste like syrup.

Adding sugar would normally bring down the FG, but you are going to be challenged with reaching the alcohol capability of yeast.

I don't brew high gravity beer, but I've always found that adding sugar doesn't affect FG. The simple sugar should just ferment out completely, and the rest should not be affected, leaving the same FG... unless the additional sugar takes it beyond the yeast's alcohol tolerance or otherwise changes the fermentation dynamics. I'm interested in what others have to say about this.

ncb---, simple sugars ferment completely; that is if you had a wort made up of simple sugars, it will ferment below 1.000. This is the reason it will lower FG. Remember in beer, we usually deal with APPARENT attenuation, and not actual attenuation. It is possible to have more than 100% apparent attenuation when fermenting simple sugars.

 

[aryoung1980]

1.018-1.030 is in-style so it definitely won't be like syrup. I would let it ride out and not add the sugar.

What yeast did you use and how big of a pitch? I just made one that was OG 1.107 that fermented down to 1.026 using WLP028 which has given me poor attenuation in the past. However, I brewed a brown ale and pitched 300mL of that yeast cake.

If it stalls out too high, I'd get a small yeast starter going with something alcohol tolerant (champagne yeast maybe?), pitch it at high krausen, and try to knock off those last few points.


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[Gameface]

This is a subject I've been trying to get my head around.

The thing is, you can up the alcohol content by adding simple sugar, but you still have exactly the same amount of residual sugar that you had without the simple sugar. So you haven't really dried it out any although you might very slightly being the F.G. down.

Does that make sense? Am I correct?

 

[wonderbread23]

This is a subject I've been trying to get my head around.

The thing is, you can up the alcohol content by adding simple sugar, but you still have exactly the same amount of residual sugar that you had without the simple sugar. So you haven't really dried it out any although you might very slightly being the F.G. down.

Does that make sense? Am I correct?

This is correct. Adding more sugar to a beer with potentially too much residual sugar isn't going to help the cause. If you're lucky, all of the simple sugars will be metabolized by the yeast. You'll end up with a beer with more alcohol, a higher overall attenuation rate, but with the same amount of residual gravity. If you're unlucky, the yeast will have pooped out, they won't finish of the simple sugars that were added, and you'll end up with a sweeter beer. In order for simple sugar to dry out a beer, it needs to replace malt based fermentables, not be in addition to them.

 

[tarcrarc]

1.018-1.030 is in-style so it definitely won't be like syrup. I would let it ride out and not add the sugar.

What yeast did you use and how big of a pitch? I just made one that was OG 1.107 that fermented down to 1.026 using WLP028 which has given me poor attenuation in the past. However, I brewed a brown ale and pitched 300mL of that yeast cake.

I used WLP001. I harvested the yeast off a previous batch. The fermentation took off big time after only an hour so I am guessing I overpitched (according to White's Yeast book). Not sure of actual volume, but it was a ton! After 4 hours from my pitch I had krausen all the way up in the neck of my 6.5 gallon carboy with only 3 gallons of wort.

I checked the gravity last night (about 50 hours in) and it was down to 1.044 with a bubble rate of about 1 per second. So, I am thinking it can go down another 15-20 points as is. I have kept it at 64 degrees since pitching.

 

[helibrewer]

You need lots of O2 with beers above 20 Plato, some brewers advocate starting with 10 minutes of pure O2 before pitching and adding additional oxygen until high krausen. Servomyces nutrient is also highly recommended. All of this needs to be done early however.

You also should have a high alcohol tolerant "finishing" yeast handy. Create a starter with this using a gravity of about 1.040 and a lot of O2. As the main beer approaches this gravity you want to pitch the helper strain while it is at high krausen into the main batch.

 

[myndflyte]

I vote don't add anything. Just let it finish out to whatever it comes to. And as already said 1.030 won't taste like syrup because there are presumably enough hops to balance out the residual sweetness.

Anyway, I say don't add anything. Barleywines are supposed to be something you can chew on (at least I think so). But depending on the yeast you used, you may want to add some wine yeast or a high gravity ale yeast at bottling to make sure you get carbonation.

 

[aryoung1980]

I used WLP001. I harvested the yeast off a previous batch. The fermentation took off big time after only an hour so I am guessing I overpitched (according to White's Yeast book). Not sure of actual volume, but it was a ton! After 4 hours from my pitch I had krausen all the way up in the neck of my 6.5 gallon carboy with only 3 gallons of wort.



I checked the gravity last night (about 50 hours in) and it was down to 1.044 with a bubble rate of about 1 per second. So, I am thinking it can go down another 15-20 points as is. I have kept it at 64 degrees since pitching.

It sounds like you've done everything right so far. I would suggest raising the fermentation temperature as you near FG. That will also help knock a few points off.



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[tarcrarc]

Thanks for all your suggestions. I also was corrected regarding my understanding of sugar additions-----makes perfect sense.

Just checked the gravity this morning--down to 1.038 with a bubble every 3 seconds. I think all will work out fine.

Based on a previous comment I now have another question. I did add additional pure 02 16 hours into fermentation. White's yeast book said we are safe to do so for such brews as this without risk. However, since this fermentation took off in the first hour of pitching and it appears I was at high krausen within 4-6 hours I am now wondering if I may have added the 02 too late.

Thanks again!

 

[ncbrewer]

ncb---, simple sugars ferment completely; that is if you had a wort made up of simple sugars, it will ferment below 1.000. This is the reason it will lower FG. Remember in beer, we usually deal with APPARENT attenuation, and not actual attenuation. It is possible to have more than 100% apparent attenuation when fermenting simple sugars.

My bad - I forgot about the alcohol going below 1.000. Still, as pointed out by gameface and wonderbread23, it leaves the same amount of residual sugar.

When I've added sugar in the boil, it seemed to yield a slightly drier tasting beer. But it was very subtle, and I wonder if it was my imagination.

 

[Calder]

This is a subject I've been trying to get my head around.

The thing is, you can up the alcohol content by adding simple sugar, but you still have exactly the same amount of residual sugar that you had without the simple sugar. So you haven't really dried it out any although you might very slightly being the F.G. down.

Does that make sense? Am I correct?

Correct, it does still have the same amount of residual sugar, but it also has more alcohol. The gravity of alcohol is a lot lower than water, so a higher alcohol beer with the same residual sugar will have a lower gravity.

 

[myndflyte]

When I've added sugar in the boil, it seemed to yield a slightly drier tasting beer. But it was very subtle, and I wonder if it was my imagination.

Not your imagination. That's what happens when you add sugar. Some styles you use added sugar to help dry it out a bit.