First Time BIAB Question

[BWBrew]

Hello, BIAB Newb here

I've been brewing extract batches for about 3 years with pretty good results and recently decided to give BIAB a try. I brewed a 4 gal APA batch and was quite pleased when I hit the efficiency (75%) and OG (1.050) of the recipe.

This evening I went to bottle the batch and took a final gravity reading and it came out to 1.020. I was disappointed with that as the recipe called for 1.010.

In spite of the FG I went ahead and bottled anyway. And I know I screwed up by not taking a gravity reading earlier in the week but in the past I never did that and always came reasonably close to the FG. I could've let it sit for a few more days and taken another reading but I didn't mainly because it had already been fermenting for 3 weeks.

So, am I at risk for bottle bombs? Or because it already sat on the yeast for 3 weeks was it most likely finished? I used Safale US-05, pitched at 70 and fermented around 67-68. Secondly, any ideas why I missed FG by so much? Too cold??

Thanks in advance

 

[JINKS]

Hello, BIAB Newb here


This evening I went to bottle the batch and took a final gravity reading and it came out to 1.020.

Mine missed and it was because I mashed way to hot. I didn't calibrate my mechanical thermometer after it arrived so instead of 156 i got 162 and my beer finished at 1.026 after 4 weeks. It's been bottled now for 2ish months and hasn't blown a bottle yet.

 

[johnsant]

Only thing I can come up with, was the yeast fresh or was it old? How was your fermentation conditions (stable or w/temp swings). Three weeks should have been enough time to ferment but now that your doing all grain need to take hydrometer readings about 3 days before you think its finished IMO. (Some beers ferment faster than others.) Oh was your wort at the right pitching temp.

 

[doug293cz]

After 3 weeks you're probably safe from bottle bombs if you had a healthy fermentation. Did you watch the progress and see things go crazy in the FV for a day or two?

When doing all grain (and yes BIAB IS AG), mash conditions are critical, particularly temperature. Temp control is not such a big deal for steeping grain. If your mash temp was too high, it's possible that you created too many unfermentable sugars, which could lead to an FG higher than the target. I suggest you check the accuracy of your thermometer, and if it is off, either determine a correction factor, or invest in a more accurate thermometer. The Thermopen is the gold standard around here, but a little pricey (~$100, but sometimes on sale for ~$80.) There are other good, lower cost options available, with only about 0.5˚ F less accuracy, and a few seconds longer to get a stable reading.

Brew on

 

[BWBrew]

My yeast was fresh. I bought it from my LHBS the day I brewed and I've never had an issue with ingredients from this shop. As for my temps, I started out around 70 and over the course of the three weeks it cooled to about 67, so nothing drastic. I'm fermenting with a Speidel fermenter so I couldn't see the action. But my airlock bubbled for almost three days.

My strike temp was 163 and the recipe called for a mash temp of 154, which I just about hit. I had to fire the burner with about 20 minutes left in the mash to bring up the temp a touch.

I'm wondering if the issue could be my thermometer. I had previously used infrared but was concerned that wouldn't give accurate readings on a large pot of wort so I used the stick thermo that came with my turkey fryer. How would I calibrate a thermometer?

Thanks

 

[JINKS]

My yeast was fresh. I bought it from my LHBS the day I brewed and I've never had an issue with ingredients from this shop. As for my temps, I started out around 70 and over the course of the three weeks it cooled to about 67, so nothing drastic. I'm fermenting with a Speidel fermenter so I couldn't see the action. But my airlock bubbled for almost three days.

My strike temp was 163 and the recipe called for a mash temp of 154, which I just about hit. I had to fire the burner with about 20 minutes left in the mash to bring up the temp a touch.

I'm wondering if the issue could be my thermometer. I had previously used infrared but was concerned that wouldn't give accurate readings on a large pot of wort so I used the stick thermo that came with my turkey fryer. How would I calibrate a thermometer?

Thanks

ice water and what ever temp water boils at for your altitude. Mine is 205 f. Then just turn the nut on the back to make the needle point to the correct temp

 

[BWBrew]

Great info. Thanks for the reply JINKS.

 

[doug293cz]

inexpensive stick dial thermometers are notoriously inaccurate. Seriously, look at getting a better thermometer.

To calibrate a thermometer measure in boiling water (you need to know the boiling temp of water at your altitude.)

You also want to measure at 32˚F (0˚C) by taking the temperature in an ice bath. A proper ice bath is more complicate than it seems. A couple ice cubes in a glass of water is not adequate. Fill a glass completely with crushed ice, and add refrigerated water to fill the empty space. Then place the thermometer tip in the center of the crushed ice mass.

Brew on

 

[Gavin C]

3 likely factors in play that can and often do lead to a high FG

1. Recipe containing a high percentage of specialty grains
2. Mash temperature was too hot in the first few critical minutes of the mash (or throughout the mash duration)
3. Yeast management


1: What is the % of specialty grains.

Solution: Lets see the recipe.

2: Strike water at 160+F. How quickly did you dough in. Faster the better gets the temperature down. This is crucially important IMO especially on my setup as I use thin full-volume mashes and miil the grain finely. A slow dough in with a strike water of 160+ will expose the grains' enzymes to possible degradation.

Solution: dough in fast. (under 1 minute) Make sure your thermometer is accurate. My dial thermometer is not. I use a Thermapen, very accurate.

3. What was the date on the yeast (calculate the date of manufacture)
Was it a dry/liquid yeast
If dry did you hydrate it
If liquid did you make a starter
If you made a starter what were its specs size, stirred etc

Solution: Use hydrated dry yeast or an appropriately sized starter with liquid yeast based on the batch size OG, date of yeast manufacture (i.e. estimated yeast viability)

Some or all of these issues may have contributed to the FG of 1.020

And just to be clear, you measured it with a hydrometer not a refractometer.


The other issue: Are you at risk of bottle bombs? Highly unlikely. 3 weeks it's done with that OG.

Hope that is some use. Food for thought I suppose. Best of luck with the next batch.

 

[BWBrew]

Thanks Gavin C,

Sounds like I don't need to worry about bottle bombs which was my major concern. And yes I used a hydrometer.

My grain bill was as follows:

6.6 lbs Pale 2 row
.4 lbs Carmel/crystal 60L
.4 lbs UK Carastan 30/37
.25 German Carapils

I don't recall how long it took to dough in but it wasn't long. I didn't linger.

I also don't recall the yeast date but believe it was fresh. It was dry yeast and I rehydrated using directions from John Palmer.

One other issue is my sample tasted a little thin. Could that be from too much water in the boil?

Thanks

 

[Gavin C]

About 13 percent specialty malts. I would be expecting an FG of about 1.015. The recipe alone wouldn't lead to a 1.02 FG

Your yeast management sounds great. Nicely done there.

This leaves mash temperature as the last remaining likely suspect cause of your beers higher than desired FG

With BIAB and mashing in a SS pot and full-volume mashes I generally see a 4-5 degree drop from strike to mash temp.

Make sure you calculations of strike temperature allow for the SS pot being at the same temperature as the water. Measure your grain temperature and time your dough-in. Shoot for less than 1 minute.

I know my posts are sometimes a Thermapen love-fest but it really is a marvelous tool. It has added a whole new level of precision to my brewery allowing me to perform more complex mashes with ease.

It very east to get one for $79 on sale and they were having an open box sale recently for $69. Sign up for their emails if you're interested and you will see all the deals.

It really sounds like mash temperature is the key here.

Nailing this is very doable