Fermentation and ABV woes

[justin81]

Just finished my 4th batch and I'm having problems getting my ABV up and I'm not sure why. I'm doing all grain and my first brew, an American Wheat, was fantastic. I used my friends equipment and fermented in a closet at 72 degrees. I then bought my own equipment and did a Cali Common in a cooler of ice at 60 degrees and it was perfect. Both beers where over 5% Then I got a free chest freezer and hooked it to a Ranco and now everything has gone to crap.

My friend and I have put our last four brews into the freezer at 63 degrees and none of the 4 batches have come out with low enough gravity drops. I've repeated both recipes in my fermenter and both have come out under 4% and my friends with double yeast pitch are at about 4.5% at the most. I'm within the specs of the yeast being used so I'm getting really confused. Just looking for some suggestions. Maybe start out my fermentation at around 70 and then bring them down to mid 60s after a few days???

 

[Yooper]

As you know, ABV is a function of the OG and the FG. If you're meeting your target OG, what's the problem? Is the FG too high?

If the FG is finishing too high, the problem probably isn't the temperature of the fermentation. It probably is one of two things- inadequate yeast pitching/underattenuating strain, or a too-high mash temp.

Can you post a typical recipe, with the yeast strain, and the mash schedule? We can take a look and see what's happening.

 

[justin81]

This is my recipe and what I got on this brew.

California Common
5 gallon batch

fermentables
11lbs American Two-row Pale
.5lbs Dextrin (CaraPils)
.5lbs Vienna Malt
.5lbs Crystal 60L
GOAL
OG - 1.067
FG - 1.018
Achieved
OG - 1.050
FG - 1.030

Mash Efficiency 74%

hops
60 mins - 0.5oz Northern Brewer
5 mins - 0.5oz Cascade

yeast
Saflager S-23

Mash @ 155 for 1hr 1qt per lb of grain
Fly Sparge @ 170 for total 6gal boil
Boil for 1hr

 

[Yooper]

I haven't used s-23, but it's supposed to give about 75% attenuation. If you're getting under 40%, there is definitely a problem.

Are you certain of your thermometer's accuracy? I ask because mashing at 155 will give you alot of unfermentables, and a higher FG as it is. If your thermometer is off even by two degrees, you could be mashing way higher, causing more unfermentables- which would give you a very high FG.

Have you mashed at 150, or 152? That would probably give you better results. I mash my steam beer at 154, but I do have problems with OVERattenuation! What about other recipes? What's the mash temperature and yeast strains that you've tried?

 

[justin81]

On the wheat i'm doing same mash schedule using the Safbrew WB-06. I hit 1.050 down to 1.004 the first time I made it at 72 degrees in my closet, and then in the freezer i went from 1.052 to only 1.020 at 63 degrees. I wanted to cool down the fermentation to lower the esters.

I may stop today and grab a new thermometer at lunch just to see if I see a difference between the one I have at home.

 

[Yooper]

I ferment almost all of my ales at 60-64 degrees (beer temp, ambient temperature is usually cooler) because I like a "clean" taste to my ales. I also use many neutral ale yeasts, like Wyeast's 1056. For dry, I like s-05 or nottingham.

Instead of raising temperatures and causing off-flavors in your beer, maybe dry using different yeasts that have an attenuation % that you'd want.

I'd try these three things- better yeast, checking the accuracy of your thermometer, and lowering the mash temp to a more reasonable mash temperature to get you the proper attenuation levels. Only a beer that you want kind of "thick" bodied and with plenty of residual sweetness should be mashed at 155 or higher.

Try mashing pale ales, wheats, and the steam beer at no higher than 152-153 and that will help a lot.

 

[justin81]

Thanks for the help Yooper!! I will repeat both recipes using all the things you mentioned.

 

[Joos]

How long do you ferment it?Lower temps usualy means more time.

 

[JPicasso]

Definatly calibrate your thermometer. I just bought a cheap glass one and it read 203°F at boiling. If I mashed with this at 155, I would actually be at 162!

Also, you are using a lager-type yeast. Try a different strain, like S-05, or Nottingham.

Hmmmmm.. I guess +1 to what Yooper said.

 

[FlyingHorse]

GOAL
OG - 1.067
FG - 1.018
Achieved
OG - 1.050
FG - 1.030

Mash Efficiency 74%

If your OG was 1.050 using this recipe, your efficiency was only ~56% assuming 5 gal to the fermenter.

Aside from all the good suggestions on improving attenuation, you probably need to revisit your mash/sparge procedure and bump up your efficiency. Who crushes your grain? Do you check your mash pH, or use a buffer? What's your water source, and do you know the chemistry? How long are you sparging, and what is the temp of the sparge water? Have you ever tried batch sparging?

 

[justin81]

How long do you ferment it?Lower temps usualy means more time.

I had it in the fermenter 6 days and the krausen had fallen. Then I pulled it and racked it to secondary where I usually leave it for another 10-14 days before bottling. I started to think the lower temps might have had something to do with it on my last brew, but just wrote it off as bad brewing on my part since my first Cali Common had sat in a cooler full of ice at 60 degrees and did great.

If your OG was 1.050 using this recipe, your efficiency was only ~56% assuming 5 gal to the fermenter.

I put it into beer math and it said it was at 74%. How do you correctly test your efficiency?

Who crushes your grain? Do you check your mash pH, or use a buffer? What's your water source, and do you know the chemistry? How long are you sparging, and what is the temp of the sparge water? Have you ever tried batch sparging?

My grain is crushed at the LHBS. I've been using spring water from Albertson's for all my brews so far. I have never checked the PH of their water though. I'm sparging at 170 degrees and I'm letting it fill to 1.5inches above my grain bed in my mash tun, and then opening both valves from my sparge tank and my mash tun to drain into my kettle. It takes about 5mins or longer I guess to collect my 6gals. I've never really timed it though. I've never tried batch sparging but will look into for sure.

Thanks guys!

 

[ericm]

trying leaving your beers in primary longer

 

[FlyingHorse]

I put it into beer math and it said it was at 74%. How do you correctly test your efficiency?

Efficiency is basically, [gravity points you captured] / [gravity points available in your grain bill].

As a quick and dirty approximation, figure that your grain has a potential of 36 points per lb per gallon (most base malts are 36-38; specialty grains are less but 36 will get you in the ballpark if your bill is mostly base malt). So using your recipe:

[gravity points you captured] = 50 pts/gal x 5 gal= 250
[gravity points available in grain bill] = 36 pts/lb x 12.5 lbs = 450

Efficiency = 250/450 = ~56%

Not sure why beer math gave you 74%.

My grain is crushed at the LHBS. I've been using spring water from Albertson's for all my brews so far. I have never checked the PH of their water though. I'm sparging at 170 degrees and I'm letting it fill to 1.5inches above my grain bed in my mash tun, and then opening both valves from my sparge tank and my mash tun to drain into my kettle. It takes about 5mins or longer I guess to collect my 6gals. I've never really timed it though. I've never tried batch sparging but will look into for sure.

Thanks guys!

Suspect #1 is your crush. LHBS crushes are notorious for yielding low efficiency. Ask your LHBS if they'll adjust the mill for a finer crush, or find a friend with a mill to crush your grains.

Suspect #2 is your sparge method. An effective fly sparge takes a lot longer than 5 minutes...back when I used to fly sparge I'd take anywhere from 45-60 minutes...some here take longer. What you're doing is essentially a hybrid fly/batch sparge, with none of the benefits of either method. Try either slowing down your fly sparge to take 45 min or so, or try a batch sparge. A good how-to here.