Two questions...bottle bombs and gravity change

[phil74501]

I just bottled a batch of honey wheat beer. I was guessing the volume at 4.5 gallons. Using Northern Brewers priming calculator, that called for 5.39 ounces. When I siphoned into my bottling bucket, I only came up with 4 gallons. I rechecked the priming calculator, that came up with 4.69 ounces. Of course by the time I realized I was only going to get 4 gallons, it was too late. Did I just create bottle bombs?

Second question. I racked the batch of honey wheat about a month ago. I checked the gravity at that time. It was 1.010. I checked it again today, I used what was left in the bottom of the bottling bucket, it was at 1.020. Did adding the priming sugar change it? Otherwise, I can't think of why it should have changed upward after being racked.

 

[Lefou]

Imprecise mixing in the bottling bucket can be prevented by switching over to glucose tabs or sugar cubes added directly to the bottle. It reduces your chance of batch overcarbing or undercarbing by a large factor because the priming is adjusted for the bottle.

Using my particular priming calculator (Brewer's Friend) it seems your priming is within the "safe" levels. For 4 gallons of ale, 4.6oz. table sugar translates over to about 3 volumes at 68F, so you look OK to me.

 

[doug293cz]

An increase of 0.010 in SG from priming is equivalent to adding 10/46 lbs/gal of table sugar (sucrose has a gravity potential of 46 ppg.) That's 16*10/46 oz/gal ~= 3.48 oz/gal. Your nominal add was 5.39/4.0 oz/gal = 1.35 oz/gal. This probably means that your priming solution/sugar was not well mixed with your beer. The implications of this is that some of your bottles will be way undercarbed, and some might be glass grenades.

The strongly primed beer (1.020, 3.48 oz/gal sucrose) in the bottom of your bottling bucket could generate 6.78 volumes of carbonation. This is in addition to the residual carbonation of about 0.9 volumes after fermentation. So, you are looking at the possibility of having some bottles with a total of about 7.7 volumes of carbonation.

Your nominal priming of 1.35 oz/gal would produce about 2.63 volumes of carbonation, so with the residual from fermentation you would be somewhere around 3.5 volumes total carbonation. On the high end for a wheat, but not outrageous.

However, since you have the possibility of bottle bombs due to poor mixing of the priming sugar, you need to take precautions. You should condition the beer in a heavy duty plastic tub with a tight fitting lid. Once your 3 week conditioning period is complete, chill all of the beers to reduce pressure in the bottles. Wear protective gear when handling the bottles (face shield, leather gloves, heavy clothing, etc.) Open the chilled bottles very carefully.

How did you mix in your priming sugar? The most recommended method is to pour the priming sugar solution into the bottom of the bottling bucket, and then rack the beer onto the priming solution thru a tube that is curled on the bottom of the bucket, such that the incoming beer creates a slow whirlpool action in the bucket in order to mix the priming solution evenly throughout the beer.

Brew on

 

[phil74501]

An increase of 0.010 in SG from priming is equivalent to adding 10/46 lbs/gal of table sugar (sucrose has a gravity potential of 46 ppg.) That's 16*10/46 oz/gal ~= 3.48 oz/gal. Your nominal add was 5.39/4.0 oz/gal = 1.35 oz/gal. This probably means that your priming solution/sugar was not well mixed with your beer. The implications of this is that some of your bottles will be way undercarbed, and some might be glass grenades.

The strongly primed beer (1.020, 3.48 oz/gal sucrose) in the bottom of your bottling bucket could generate 6.78 volumes of carbonation. This is in addition to the residual carbonation of about 0.9 volumes after fermentation. So, you are looking at the possibility of having some bottles with a total of about 7.7 volumes of carbonation.

Your nominal priming of 1.35 oz/gal would produce about 2.63 volumes of carbonation, so with the residual from fermentation you would be somewhere around 3.5 volumes total carbonation. On the high end for a wheat, but not outrageous.

However, since you have the possibility of bottle bombs due to poor mixing of the priming sugar, you need to take precautions. You should condition the beer in a heavy duty plastic tub with a tight fitting lid. Once your 3 week conditioning period is complete, chill all of the beers to reduce pressure in the bottles. Wear protective gear when handling the bottles (face shield, leather gloves, heavy clothing, etc.) Open the chilled bottles very carefully.

How did you mix in your priming sugar? The most recommended method is to pour the priming sugar solution into the bottom of the bottling bucket, and then rack the beer onto the priming solution thru a tube that is curled on the bottom of the bucket, such that the incoming beer creates a slow whirlpool action in the bucket in order to mix the priming solution evenly throughout the beer.

Brew on

I was aiming for 3 on the carbonation volume.

I poured the priming sugar in the bottom of the bottling bucket. My fermentors have spigots on them. I attached a tube to the spigot, placed the tube in the bottom of the bucket, opened spigot. Basically what you just described. I also used a spoon to stir with after all the beer was in the bottling bucket...just to make sure it was mixed up well.

 

[doug293cz]

I was aiming for 3 on the carbonation volume.

I poured the priming sugar in the bottom of the bottling bucket. My fermentors have spigots on them. I attached a tube to the spigot, placed the tube in the bottom of the bucket, opened spigot. Basically what you just described. I also used a spoon to stir with after all the beer was in the bottling bucket...just to make sure it was mixed up well.

Sounds like you did things correctly. Any possibility that the 1.020 SG reading was in error? The amount of priming sugar you added should have taken your SG from 1.010 to about 1.014. I don't know any way to increase SG other than add more dissolved solids (in the usual case sugar), or evaporate off a lot of water/alcohol (not likely post fermentation.)

Brew on

 

[phil74501]

No, don't think so. I still have it sitting in the test tube. What I used to take the reading from was what was in the bottom of the bucket. It was just some final left overs. There was some lees in the bottom of the bucket. Could that be it?

 

[doug293cz]

No, don't think so. I still have it sitting in the test tube. What I used to take the reading from was what was in the bottom of the bucket. It was just some final left overs. There was some lees in the bottom of the bucket. Could that be it?

I suppose the leas/trub are a possibility. Since you still have the sample, cover it and put it in the refrigerator. In a day or two the trub should settle out. Warm it back up to your hydro's calibration temp, and measure the SG again. If it's 1.013 to 1.015, then you should be ok.

Brew on

 

[phil74501]

Okay, I'll give that a try. Thanks.

 

[phil74501]

I think I figured out my problem. It occurred to me this morning when I woke up. When I put in the priming sugar, I didn't mix it with water first, and let it boil for a few minutes. I just dumped it straight into the bottling bucket. I'm not sure why I did that...I just did. Could that have been why my gravity was high?

 

[doug293cz]

Absolutely. In order to mix easily, you have to pre-dissolve the sugar.

Brew on

 

[phil74501]

So do I have bottle bombs in the making?

 

[doug293cz]

About all that can be said is: maybe. You will definitely have some that are undercarbed due to poor mixing of the priming sugar. The question that can't be answered is: did any of the bottles get enough sugar to be a danger? You can either accept the risk, or dump all of the bottles now. If it were me, I wouldn't risk it unless I had the protective gear I listed in a previous post. But, it's your decision to make.

Brew on