Some time ago, I wrote about dimethyl sulfide, an extremely useful flavor chemical, but one whose usefulness in some flavors is very dependent on its level of purity. On storage, dimethyl sulfide oxidizes to dimethyl disulfide and dimethyl trisulfide. These impurities make a very dramatic difference to the optimum level of synthetic dimethyl sulfide that can be used in flavors, where it is a quantitatively important component in nature.
Blackcurrant flavors are a great example. High purity dimethyl sulfide can be used to great effect at 5,000 ppm. Typical grades of dimethyl sulfide, containing only one or two percent of impurities can only be used at a fraction of this level, around 200 ppm. This puts dimethyl disulfide and, even more so, dimethyl trisulfide firmly in the mental category of off-notes to be avoided at all costs. From my own personal experience, that impression was compounded by childhood memories of a large pond my father had constructed in our yard. Without regular attention, the pond would sometimes develop a distinctly rural and unpleasant miasma of dimethyl trisulfide.
The profile of the dimethyl sulfide series of chemicals changes with increasing molecular weight from jammy (sulfide), through jammy/putrid (disulfide), putrid (trisulfide) to meaty (tetrasuldide). Added to this, there are dramatic variations in strength, dimethyl trisulfide is many hundreds of times stronger than dimethyl sulfide. Despite the mental associations of high levels of the compound, at low levels the putrid note of dimethyl trisulfide can actually be very attractive. It is the key driver of the profiles of cauliflower, Brussel sprouts and many related vegetables, all of which I really like.
Note that the dose rates given throughout this article are the levels suggested for use in flavors intended to be dosed at 0.05% in ready-to-drink beverages or in a simple bouillon.
Cabbage: Cruciferous vegetables, commonly referred to as the cabbage family, all contain significant quantities of dimethyl trisulfide. Demand for flavors in this category is a little limited, but 50 ppm of dimethyl trisulfide will always form a good starting point.
Chives: Chives are a little more interesting than simply a green version of onions, they also have a noticeable cruciferous note. A level of 5 ppm of dimethyl trisulfide is a good level to obtain this effect.
Garlic, Fried: In contrast, this ingredient is much more helpful in cooked garlic flavors than in fresh profiles. An ideal level of addition is 20 ppm.
Mushroom, Cooked: The same is true of cooked mushroom flavors, but 2 ppm of dimethyl trisulfide is all that is needed to add welcome realism and complexity. Higher levels work well in shitake mushroom profiles.
Olive: Black olive flavors can be quite a challenge. Dimethyl trisulfide helps to round out the profile and adds realism at two ppm.
Onion: Dimethyl trisulfide functions in cooked onion flavors in much the same way as in cooked garlic flavors and the same level of addition works, 20 ppm.
Potato, Fried: All styles of cooked potato, especially fried, benefit from this ingredient. An ideal level is 10 ppm.
Rice, Cooked: The best level of dimethyl trisulfide in cooked rice flavors depends a great deal on the other ingredients, but 5 ppm is a good place to start.
Tomato: Dimethyl trisulfide should be used with great care in fresh tomato flavors, but it adds authenticity to cooked tomato and tomato puree flavors at 10 ppm.
Truffle: It is all to easy to make truffle flavors based around a single ingredient but, even with truffles, a little complexity helps. A useful level is 5 ppm.
Beef, Roast: Dimethyl trisulfide has the most obvious connection in savory flavors with chicken, but it is almost equally effective in beef flavors. A good starting point in roast beef flavors is 5 ppm. This ingredient is also effective in boiled beef flavors, but the level is a little lower.
Bread: Lower levels, around 2 ppm, work well in bread flavors and also perform the same function in pizza base flavors.
Chicken: No real surprise that this idiosyncratic raw material works so well in all chicken flavors, ranging from long boiled to freshly fried. A great place to start is 5 ppm.
Ham: Ham flavors only require a subtle contribution from this note, but the effect is, nevertheless, interesting at 1 ppm.
HVP: The effect of dimethyl trisulfide in HVP flavors is rather similar to that in other savory notes and 5 ppm is a defining level of addition.
Lamb: The same comments apply to lamb and mutton flavors. A good place to start is 5 ppm but higher levels can also work.
Seafood, Fish: This ingredient should be used with caution in fish flavors, but 1 ppm can be helpful in non-oily fish profiles.
Seafood, Shellfish: The precise opposite is true of shellfish flavors and much higher levels can be used to good effect, especially in lobster, crab and scampi flavors. An addition of 10 ppm and more work very well.
Cheese, Cheddar: The dimethyl trisulfide note tends to develop most in cheese flavor types that have been either cooked during processing or stored extensively. Cheddar cheese fits both criteria and three ppm works well.
Cheese, Parmesan: Parmesan also fits both criteria and a slightly higher level of addition, around 5 ppm, works well.
Cheese, Toasted: Most commercial toasted cheese flavors are Cheddar type and a somewhat higher level works well with the toasted note, in the region of 5 ppm.
Cream: Cream does not fit into either of the above categories in even the slightest degree, nevertheless dimethyl trisulfide adds an interesting nuance at 5 ppm and does not detract in any way from the freshness of the profile.
Milk, Condensed: Condensed milk and dulce de leche flavors are both served well by moderate levels of this ingredient, around 5 ppm.
Yogurt: Yogurt flavors, in respect of this note at least, function similarly to cream flavors. A good starting point is 5 ppm.
Chocolate and Cocoa: Once outside, the very predictable savory and flavors, dimethyl trisulfide could find it hard to gain traction. Chocolate and cocoa flavors are the exception and the best level for these chemicals away for further work. An addition of 5 ppm works well in cocoa flavors and, only very slightly less, 0.04% rtd.
Durian: Of all fruit flavors, durian has an absolutely unique profile. The gassy sulfur note is celebrated by aficionados and is derived in nature from a complex mixture of sulfur chemicals. A level of 5 ppm of this ingredient makes a notable contribution to an authentic durian flavor profile.
Lychee: Lychee flavor also has a distinct sulfur component, but it is much less pronounced than durian. 0.1 ppm is a good level.
Papaya: Papaya flavors vary dramatically but, if an authentic fully ripe style is the objective, then an addition of dimethyl trisulfide as high as 2 ppm works well.
Peanut: A similarly robust addition, around 3 ppm, is equally effective in peanut flavors, adding authenticity and impact.
Watermelon: The addition of dimethyl trisulfide to fruit flavors that are not overtly sulfurous is a question of taste, but one ppm in watermelon flavors gives an interesting and fairly realistic effect to a flavor profile where, sadly, realism may not always be the goal.