How do you achieve the proper moisture to age tobacco without mold issues

[davek14]

I smoke a pipe and am commonly tinkering with blending and lightly casing my tobacco. Mold has been a huge issue for me and has ruined too many "perfect" batches I've put up for storage.

I had given up on letting my blended tobacco age. I've been taking the leaf from storage in cardboard boxes and mixing as I go, making up just enough to use for a few weeks at a time. Any batches I jar for later use, I attempt to get bone dry so as to avoid mold.

Yesterday, I cracked a jar which I had thought was dry when put up about 9 months ago. It must have had a chunk or two which had some moisture though as the tobacco was a little moist, about perfect for smoking.

And when I cracked that jar, it had a great, fine tobacco, smell. The tobacco also burnt slowly and had the consistency of good pipe tobacco, even though some of the leaf used had been a little thin. In short, it did all the great things aging can do had happened.

So, how do I do this again? Just a little too much moisture and the 'baccy will mold, but just the right amount gave me wonderful results.

How do you store tobacco in jars to age? Any ideas at all.

 

[tullius]

Let sit at, or less than 65 percent RH for a week, vacuum seal in a mason jar. The closer you can get to 65 the better it will age. Done.

 

[tullius]

If you're having problems with mold, err on the dry side and leave out the case.

 

[ChinaVoodoo]

I don't understand why your unblended tobacco doesn't mold but your blended tobacco does. Are you adding moisture when you make your blends?

 

[ChinaVoodoo]

Right! The casing. Look at me paying attention.

Here's the thing. If you think in terms of the percentage of water in the tobacco, 12-15% by total weight is what you're aiming for.

So if you have 100g of tobacco which is in case, it is actually about 85g tobacco and 15 g water. Then if you added 15g of casing, it's now about 26% water (30÷115). Way too high.

So the trick is to weigh your tobacco pre-cased, and to dry it out post-casing until it gets back down to the original weight.

 

[ChinaVoodoo]

Likewise, if you have bone dry tobacco and want to bring it into case, you can take the weight, times it by 0.15, and add that much water. That will bring it up to about 13%. (15÷115)

 

[tullius]

CV's right: if the blended cased stuff molds and the unblended uncased doesn't, it's the casing.

What are you using to case? Bet it contains mold food, or adds too much moisture to the tobacco, or both.

 

[deluxestogie]

mold food

Tobacco leaf lamina are mold food. Just add water.

I dry-down a blend until it is nearly bone dry. Then I wet my finger, and flick a few drops into the container before closing it. Just a bag or a plastic jar--no vacuums or sealing. Check it in a couple of days. If it needs a tad more moisture, then I flick in a few drops more. If I had to use a scale every time I adjusted the moisture of my pipe blends, I would just shoot myself in the foot, and go home.

Storage location also makes a difference. If the container is subject to swings in temperature, then one surface is likely to condense moisture from within the container, even if the water content is perfect. The larger the quantity of tobacco contained, the greater the likelihood of condensation during temperature swings. [If I'm so smart, how come I threw out a half-pound bag of molded, home-made perique two days ago? It breaks my heart.]

About the casing: If you want to add casings to tobacco that you plan to store, then your choices are to either dry-down the cased tobacco way more than you see with cased commercial pipe tobaccos, or you need to add polypropyleneglycol (PPG), to inhibit mold growth--not to mention inhibiting burn. I guess the message here is that cased commercial pipe blends are poor examples to emulate.

Bob

 

[Jb00]

Likewise, if you have bone dry tobacco and want to bring it into case, you can take the weight, times it by 0.15, and add that much water. That will bring it up to about 13%. (15÷115)

Seems like you put a lot more thought into it than I do. I just mist them a little then shred and leave them out to dry for a few hours.

 

[ChinaVoodoo]

I grew up working for my dad in a butcher shop and I honestly don't know what the problem with operating a scale is. It's a sure thing. Nail the moisture level, maintain the moisture level.

mold food

There is a range from agar to lamina, and its a reasonable theory that casing is somewhere in between.

 

[GreenDragon]

Many of the casing recipes I’ve seen have some sugar component to them (honey, chocolate, molasses, maple syrup, etc) which is also mold food. If you don’t want to add PPG or other chemicals, then I would suggest using more natural preservatives such as alcohol and a pinch of salt in the mixture instead of water. 15% ethanol is typically the upper range that most yeast and other fungus can tolerate. I like rum personally, but vodka would be a neutral option. I’ve successfully used a mix of 50/50 water and rum in my pipe mixes. I spray to moisten, toss to mix, let dry till it doesn’t feel “wet” any more, then jar.

 

[davek14]

Reason my leaf does not (usually) mold in boxes is because it's pretty dry and has airflow. I keep it in cardboard boxes in a waterproofed basement. When I check it, it is usually dry enough to require care so that it does not crumble, but is sometimes pliable. It's likely on the dry side to age, but does age slowly.

When I mix a batch, it is usually mostly Burley. I add Bright Leaf most commonly, but also add other stuff (mostly to use it up and be frugal). As to casing, I use the smallest amount of honey possible. It doesn't take much honey at all to mellow Burley. If I taste honey, I'll add more tobacco and re-mix. I do press the tobacco overnight to blend flavors, and I get it quite moist to do that. So, the casing is an issue, but not much of one. Deluxestogie is right. Tobacco is mold food on it's own.

So, the tobacco is pretty damp out of the "press" and I leave it out to dry to a proper moisture. It seems that as long as it is open to air and drying, it won't mold. I can leave a pressed cake out, I can leave the diced cake out, I can even leave the tobacco in open jars… and it won't mold. If I seal a jar, however, unless I get it *crispy* dry it molds.

So, all that works. I avoid mold as long as my tobacco is a work in progress and I can even store some for later if it's bone dry. Crispy dry tobacco in jars does not age, though.

Aging in jars seems to be a different process than aging your leaf in boxes. If anyone is on pipe smoker's forums you might have read about it.

Back to the jar I "messed up" with and left too much moisture in. I guess I just lucked out and left just the right amount of moisture in that jar. It aged 9-10 months and smelled delicious upon opening. Almost even more importantly, it felt "thicker", was more like pipe tobacco, and burnt slowly, all with no additives.

I don't think there was honey in this batch, I *think* I was adding some Perique to Dark Madole to use up the Madole. But I seriously don't think the honey is a big factor. when I add it, it is as small an amount as possible. A quart mason jar with tobacco pressed into it likely has about 1/8 teaspoon.

Lot's of great thoughts and ideas in this thread and I have been absorbing them. Deluxstogie's idea to start bone dry and then "add water dropwise" might be an experiment to try. Prolly still be kinda dry, but would just age a bit slower.

 

[deluxestogie]

S.S. Block, 1953.

Everything can mold. Below an RH of 75%, it takes a long time.

Bob

 

[tullius]

^the added nutrients seem important^

 

[tullius]

I'll bet 10lbs of cigar leaf that the first two ingredients of the "nutrients" in the cited study are water and sugar.

hint 1: I never suggest a bet I'm not certain I'll win
hint 2: Czapek-Dox broth

 

[deluxestogie]

Most forum members find arcane quibbles about scientific studies to be boring and annoying. I don't like to dump too much info, but rather the essential conclusions. This particular study on mold compared the rates with and without added nutrients.

Here is the entire study (7 pages), for those with time to kill. For a scientific study in applied microbiology, it's surprisingly easy reading.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1056928/pdf/applmicro00290-0019.pdf

Below are excerpts from the article:

Each material was tested both with and without the added nutrients supplied by the Czapek-Dox broth.

From the experiments described here and those given in the literature, at atmosphere of 65 per cent R.H. or less, might be considered safe for permanent storage of all materials.

...the materials which are most hygroscopic [moisture absorbing] are most susceptible to mold growth and vice versa.

...differences are not due to the presence or absence of nutrients has been shown...

The mold is apparently able to secure for itself moisture taken from the air by the substrate. The greater the quantity of water absorbed by the substrate, the more water becomes available to the mold.

If the "safe" equilibrium moisture content of 12 ± 2 per cent holds generally for all materials, the potential susceptibility of new materials to mildew may be determined by measuring the equilibrium moisture content of the new material at the humidity at which it is to be kept. If this figure is below 10 per cent, it is likely that the material will not mildew, whereas if it is above 14 per cent, the material will mildew if all the other requirements for mold growth are satisfied.

...the data in this paper appear to indicate that nutrients and inhibitors affect essentially the rate of growth and not the minimum humidity for mold growth...

CONCLUSIONS
The more hygroscopic a material, the lower the relative humidity at which it was found capable of supporting mold growth.

The rate of mold growth was stimulated by additional nutrients and retarded by a fungicide, but the ultimate extent of mold growth and the minimum humidity at which the material was susceptible did not appear to-be appreciably affected.

It is concluded that the water-absorbing properties of the substrate play an all-important role in determining the limiting humidity of the atmosphere at which mildew will occur. It is postulated that the fungus is incapable of obtaining moisture for mycelial development directly from the atmosphere (except at 100 per cent R.H.) but derives it from the substrate which obtains the moisture from the atmosphere.


My apologies to the rest of the forum.

Bob

 

[tullius]

Some of the hypotheses & conclusions are supported and some are not (premesis or conclusion not supported by the data).

e.g., p. 291: "With cheese there was very little difference in rate of growth, indicating, as would be expected, an abundance of readily available nutrients. All of the other materials showed a definite increase in the rate of mold growth where additional nutrients were provided."

I don't have time right now to break the rest down. Interestingly, the study was entirely conducted so that no material samples were below 85 deg F.

Those interested can read the report, which is valuable. Thanks Bob for citing it.

 

[ChinaVoodoo]

I have noticed differences between tobaccos. I can't help but suggest that the hygroscopicity, if that's a word, swings both ways. In 2015 my MD609 sat for too long before hanging. It became a brittle tobacco that was not as hygroscopic as most tobaccos. It therefore required high humidity for it to become subtle. I would estimate that that it would require 80% atmospheric rh% to attain even a 12% moisture content. So it would mold even when apparently dry.

 

[deluxestogie]

I have some kilned tobacco varieties that suck the moisture out of the air indoors, even during the dry winter months, in conditions that leave others crispy dry. Different finishing methods, such as perique pressure-curing, press-cake, Cavendish, etc., also alter the hygroscopic nature of the tobacco.

Bob

 

[MysticMapacho]

Something else to think about is where you're processing your tobacco. For instance, if you're processing your tobacco in a basement with even the slightest bit of mold this could potentially introduce mold spores into your tobacco. If this is the case I would recommend processing your tobacco in a completely mold free area. Just a thought.