What the science says about casing.

[hayfield311]

Hello friends. In this thread I'll share some infos on casing from multiple scientific papers and tobacco experts since there's a lot of misinformation floating around in tobacco community about casing and humectants such as PG and VG. Most of the text is copy pasted from the source.


On casing
Casings usually are applied by spraying or dipping a portion of the leaf or the entire leaf. They are composed of water, sugars (fruit extracts and honey), humectants and flavor (cocoa and licorice).
Licorice and Cooca are used in Burley tobaccos. Honey is used in Virginia.

Source


How much casing?

• It’s up to the blender, but 15–20% of the dry tobacco weight is a common number. Add whatever u want to a 100ml of water (because its hard to work with a 10ml solution) then use only 15 or 20% of it and spray it to a 100g of tobacco.
  Source
  (You can go as low as 5% if u want more of the tobacco flavor)
• Burley leaf has the ability to absorb up to 25% of its weight of added material
  Source

On Citric Acid

Citric Acid was found to remove the undesirable sharpness and pungency and render the tobacco smooth and agreeable like a tobacco of much higher quality.

Read more here
2% could be too much, this paper suggests using from 0.5% to 1%


On Sugars

• Sugar was introduced into US blended cigarettes in 1913 as a result of a decline in chewing tobacco manufacturing, utilizing essentially the same tobacco-casing formulation. The resulting taste was instantly accepted by the American public.
• The types and amounts of various sugars added to tobacco blends will vary from manufacturer to manufacturer and from blend to blend.
• Percent total sugars among US brands covers a range of about 8-12% by weight although it is not known how much is added sugar nor in what proportion the sugars are distributed between bright and burley tobaccos in the blend
• Two important sweetening agents in cigarette manufacture in the United States are maple sugar and honey, which are both used - in saucing or casing of cigarette tobaccos because of the particular aroma they impart to fresh cigarettes and cigarette smoke .

Source


On the role of humectants in tobacco

• Glycerol, Propylene Glycol, and Sorbitol are examples of polyol compounds (traditional humectants) that have been widely employed in tobacco production for moisture adsorption and retention.
  Source
• PG allows the dissolving of many flavoring substances, has low volatility, and provides good protection of the most volatile flavor compounds.
  Source
  (This means PG will help the flavors stay bound to the tobacco)
• Propylene glycol appears to have a specific inhibitory effect against bacteria and most molds; the addition of 10% w/v propylene glycol was found to inhibit the growth of these organisms.
  Source
  (It could effect the good microbes)

How much humectants (PG or VG or both) to add?

• Typical total humectants concentration ranging from 1% to 5% of the dry leaf weight
  Source

(2% is the sweet spot for me, so you want to add 2-5ml of PG to your 15-20 ml casing solution to a 100g of dry leaves)


The dangers of Propylene Glycol

• Most of propylene glycol is transferred to smoke at levels that are high enough to irritate the eyes and airways.
• It produces harmful substances when it is burnt like propylene oxide.
• Propylene oxide has been classed as a possible cancer-causing.

Source

 

[StoneCarver]

I really appreciate this information. I'm not so interested in using casing to "add flavor". However, I am interested in using casing to alter the chemistry of the smoke such as using citric acid. So, any info on the chemistry effects of casing ingredients is something I'm always interested in learning about. I like my tobacco a bit on the dry side so I have no interest in humectants.

 

[deluxestogie]

Casing information floating around FTT:

Casing

Casing is typically a liquid solution applied to stripped and shredded leaf in the production of Pipe and Cigarette tobacco.

forum.wholeleaftobacco.com

Bob