Active humidifcation and sorption isotherms of tobacco

[Ropey]

I know that pipe tobacco is usually stored simply in airtight packaging without humidification. However, the cigar-smoking part of me chafed at this idea so I did a little research.

Thought this was an interesting read, a German Transport Information Service publication on the storage and transportation of tobacco. It's an excellent "Cliff's Notes" on tobacco in general:

http://www.tis-gdv.de/tis_e/ware/genuss/tabak/tabak.htm

Specifically, it gives these two sorption isotherm graphs with regard to RH and water content of tobacco, Oriental and Virginia:

http://www.tis-gdv.de/tis_e/ware/genuss/tabak/abb20.htm
http://www.tis-gdv.de/tis_e/ware/genuss/tabak/abb21.htm

"The main problems in transporting tobacco result from its hygroscopicity: conditioning of the tobaccos with respect to their water content (10 - 12% Virginia, Burley, 12 - 14% Oriental) is tightly specified. If the relative humidity is excessive, the tobacco absorbs so much water vapor that it becomes a nutrient medium for molds. Mold, mustiness, mildew stains and a musty odor reduce the quality of the tobacco. Oriental tobaccos are the most sensitive of all tobaccos to the effects of moisture. Their sorption isotherm shows that, at water contents of 12 - 14%, these tobaccos are at equilibrium with relative humidities of 60 - 65%. If the water content is higher than the recommended values (14%) or ventilation is inadequate (dead air zones), mustiness and decay may arise within just three days due to the mold Oespora tabaci."

So by eyeballing the graphs, here's an approximation of the related moisture by weight of the tobacco vis-a-vis the RH in which it's stored. I had to average the water weight of the Orientals and Virginias, which differ slightly at the same RH (the Virginias suck up less water):

58 RH: ~12%
60 RH: ~13%
*62 RH: ~14%
*65 RH: ~15%
*69 RH: ~16%
*72 RH: ~18%
80 RH: ~21%

The starred humidities above have Boveda packets in that RH.

If you have a blend with a higher proportion of Virginia-like tobaccos, a higher RH could be used. With a higher proportion of Oriental tobaccos, a lower RH would likely be called for.

In short, if I were going to store my pipe tobacco with active humidification, I would likely use Boveda 62s. Of course, if you want a drier or wetter smoke, the RHs would be adjusted accordingly.

[NeverBend]

I know that pipe tobacco is usually stored simply in airtight packaging without humidification. However, the cigar-smoking part of me chafed at this idea so I did a little research.

Thought this was an interesting read, a German Transport Information Service publication on the storage and transportation of tobacco. It's an excellent "Cliff's Notes" on tobacco in general:

http://www.tis-gdv.de/tis_e/ware/genuss/tabak/tabak.htm

Specifically, it gives these two sorption isotherm graphs with regard to RH and water content of tobacco, Oriental and Virginia:

http://www.tis-gdv.de/tis_e/ware/genuss/tabak/abb20.htm
http://www.tis-gdv.de/tis_e/ware/genuss/tabak/abb21.htm

"The main problems in transporting tobacco result from its hygroscopicity: conditioning of the tobaccos with respect to their water content (10 - 12% Virginia, Burley, 12 - 14% Oriental) is tightly specified. If the relative humidity is excessive, the tobacco absorbs so much water vapor that it becomes a nutrient medium for molds. Mold, mustiness, mildew stains and a musty odor reduce the quality of the tobacco. Oriental tobaccos are the most sensitive of all tobaccos to the effects of moisture. Their sorption isotherm shows that, at water contents of 12 - 14%, these tobaccos are at equilibrium with relative humidities of 60 - 65%. If the water content is higher than the recommended values (14%) or ventilation is inadequate (dead air zones), mustiness and decay may arise within just three days due to the mold Oespora tabaci."

So by eyeballing the graphs, here's an approximation of the related moisture by weight of the tobacco vis-a-vis the RH in which it's stored. I had to average the water weight of the Orientals and Virginias, which differ slightly at the same RH (the Virginias suck up less water):

58 RH: ~12%
60 RH: ~13%
*62 RH: ~14%
*65 RH: ~15%
*69 RH: ~16%
*72 RH: ~18%
80 RH: ~21%

The starred humidities above have Boveda packets in that RH.

If you have a blend with a higher proportion of Virginia-like tobaccos, a higher RH could be used. With a higher proportion of Oriental tobaccos, a lower RH would likely be called for.

In short, if I were going to store my pipe tobacco with active humidification, I would likely use Boveda 62s. Of course, if you want a drier or wetter smoke, the RHs would be adjusted accordingly.

Hi Ropey,

Excellent post (thanks for the rH conversion table). Keep in mind that some (many) tobacco manufacturers use propylene glycol that will affect humidity loss

[JustTroItIn]

[Emperor Zurg]

To hell with all that. One of the many reasons I like pipes over cigars is the ease of sealing and storing pipe tobacco. Just give it a pinch. Keep it between crispy and clumpy and you're all set.

[Branzig]

Interesting read for sure, but I am with @Emperor Zurg .

Buy tobacco, jar tobacco, smoke tobacco. I like to keep it as simple as possible. Active humidification in my pipe tobacco? No thank you.

[Ropey]

To each his own.

For the future, I'm gonna drop a mini 8g Boveda 62 pack in the bottom of each pipe tobaccy mason jar. I've already found that, after a week, my English blend (sitting at the bottom of an 8 oz jar) is a bit drier than when I opened it.

[NeverBend]

To each his own.

For the future, I'm gonna drop a mini 8g Boveda 62 pack in the bottom of each pipe tobaccy mason jar. I've already found that, after a week, my English blend (sitting at the bottom of an 8 oz jar) is a bit drier than when I opened it.

You may be onto something

[mooster]

To each his own.

For the future, I'm gonna drop a mini 8g Boveda 62 pack in the bottom of each pipe tobaccy mason jar. I've already found that, after a week, my English blend (sitting at the bottom of an 8 oz jar) is a bit drier than when I opened it.

Of course it was; the longer you smoke out of the jar, the more air replaces the tobacco. Plus, that air leaves (with the moisture from the tobacco) every time you open the jar. But that's not storing tobacco, that's smoking it.

[Ropey]

But that's not storing tobacco, that's smoking it.

Huh?

Look, whatever you want to call it, I'm gonna put Bovedas in with my pipe tobacco. If nobody else here wants to, I don't give two monkey turds. I was merely posting something for posterity in case some dude down the road wants to actively humidify his pipe tobacco like I do and searches for the proper humidity on the interwebs. The fact that this thread will live forever in the cyber-ether means my mission has been accomplished.

That is all.

[mooster]

Gotcha. You want opinions on the other thread, but not on this one. I'll try to keep it straight.