Marinara: Chemical Reactions and Extraction

Understanding the chemical reactions and flavor extraction that occur in food are among the pillars of good cooking. Melding the flavors of garlic and herbs into tomatoes to make a delicious sauce is little more than a combination of chemical reactions and extraction. By chemical reaction, I mean transforming one ingredient into something very different and (hopefully) more delicious by way of molecular processes.

As we’ll see, when we prepare garlic, we’re relying on chemical reactions to obtain our desired flavor. Likewise, when I refer to extraction, I mean the process of removing a flavorful substance from one ingredient, to put into another. As a matter of clarity, extraction involves two components: The first is the extracted component or solute (our chemically reacted garlic along with herbs) and the second is the component into which we’re extracting or solvent (our tomatoes, or more precisely, our tomato juices).

Reactions in Garlic

The chemical we associate with the flavor of garlic, allicin, strangely is not directly produced in garlic cloves. Rather, allicin from garlic is created from the reaction of two separately occurring chemicals, alliin and the enzyme alliinase. These chemicals are each found in different parts of the microscopic cells of garlic. The act of chopping, mincing or crushing garlic is what allows the two chemicals to come together, react and form allicin, the garlic flavor. The finer the chop or mince, or rigorous the crush, results in a more intense garlic flavor.

Article 005 - Chemical Reaction and Extraction - Allicin

This is why, for example, roasting whole garlic results in less intense garlic flavor. Although during roasting, cells break down under heat and some of the alliin and alliinase manage to come together to form allicin, not to the same extent as chopping, mincing or crushing. The key, in other words, to maximizing garlic flavor is to break more garlic cells and release more reactive alliin and alliinase through ever more thorough chopping, mincing or crushing.

Article 005 - Chemical Reaction and Extraction - Amylase

There are also other important chemical reactions in garlic, however. That deliciously complex sweetness in roasted garlic is actually the result of a series of other chemical reactions. The reactions start between the enzyme amylase and the natural starch in garlic. Amylase breaks down the starch into simple sugars. With continued moderate heat, a secondary Malliard reaction may then take place, in which the simple sugars react with amino acids in the garlic, making even more complex and delicious flavors. This, as it turns out, takes time. As a result, large, whole pieces of garlic that may remain within a critical temperature range more reliably are optimal for producing the Malliard reaction.

For more details around the science of garlic, read my Guide to Garlic.

Extraction – Temperature, Time and Attention

Without getting too far from the topic of marinara sauce, let’s consider tea for a brief moment. We make tea with tea leaves (solute) and water (solvent) In the case of making really good tea, in addition to using high quality ingredients, it’s important to get the temperature of the water, timing of the steep and the amount of tea leaves just right to produce the perfect cup. Steep it at too high a temperature, for too long a period or with too much tea leaf, and you may end up with bitter tea, lacking in nuance. As many enthusiasts will tell you, brewing an excellent cup of tea is more complicated than you would think. But, arguably, not as complicated as making sauce. As a result, tea serves as a great analog for understanding extraction.

Very basically, the flavor components of tea can be broken down into three basic categories, what I’ll refer to “Initial,” “Base” and “Deep” extracted flavors. The initial extracted flavors in tea come out first, are light, volatile and generally the most complex. These flavors are lost first as tea grows stale with time as well as when steeping tea for too long or at too high a temperature. The base extracted flavors are what we more commonly associate with any particular tea. They’re the pleasant core flavor of the tea, are less complex than initial flavors and generally linger even after tea begins to turn stale or if tea is extracted for too long or at too high a temperature. Finally, there are the deep extracted flavors from tea. These flavors are usually vegetal, bitter, tannic and generally undesirable in too great a concentration. If you steep for too long or too hot, you start to get these flavors in your cup. Luckily, deep extraction flavors aren’t particularly discernable until after significant steeping time.

Article 005 - Extraction Curve

And everything is like tea. Kind of. In the sense that all extraction more or less conforms to the chart above, everything is like tea. To return to our marinara sauce example, all of our extracting components (herbs and tomatoes) and even our extracting medium (tomatoes) are just like steeping tea. Herbs impart an initial complex, light and nuanced flavor followed by the more distinctive herbal flavor. In the end, however, it’s all vegetal bitterness. Garlic is the same, there is an “initial” and undesirable heat and greenness to garlic that you should cook away. But this is followed by the “base” allicin garlic flavor that we love so much, along with “deep” sulfur compounds that add further complexity. Although we’re not extracting flavor from tomatoes, tomato flavors follow the same trajectory as depicted in the chart, as well, with delicate freshness representing the initial flavors, delightful tomato-iness as the base and heartier flavors waiting for you at the deep end.


Although I know I said you need to think deeply about all of your five ingredients, we can think relatively less deeply about salt. In brief, salt enhances foods by essentially turning up the volume of savory flavors by denaturing proteins and making them more accessible to olfaction or smell. Salt also turns down the volume of bitterness and makes sweet and sour tastes seem more in harmony by almost bridging the taste gap between the two and rounding off rough flavor edges. In the case of a marinara, err on the side of under-salting rather than over-salting and stay consistent with one brand of salt that you’re familiar with to avoid over-salting. The tomatoes basically need just enough salt to pop their savoriness and balance the sweet and sour of the tomatoes on the palate and the nose. Any more salt than that tends to detract from the nuance of flavor. Also, use a mineral balanced salt, like kosher salt. Regular table salt tastes slightly metallic and will upset the balance of your dish with that metallic harshness.

Now You Know How To Fish…

Now that we’ve put marinara sauce through the bottleneck, thinking through each component of the sauce before we move forward, it’s of course time to execute a fine sauce. But beyond that, you’re now armed with the ability (in principle) to think through all recipes and dishes in the same way, examining and understanding each part before you move to the next. This is how amazing sauce, and indeed amazing food, gets made.

Continue to the part three, The Recipe.

Go back to part one, Marinara: A Multi-Part Guide.

Have a question? Ask me anything!


4 Comments Add yours

  1. Wow cuz this is excellent work! Congrats and keep it up.

  2. Kayla Mather says:

    The stuff is quite helpful.

  3. Robert Ramirez says:

    Thank You for a well written and studied article on garlic and tomatoes. Considering cooking, learning ” tricks” along the way is OK , but understanding the chemistry behind it all is invaluable. I learned a great deal
    Bon Apetit..!!!

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