Wine 101: Oak, Part One

Oak Aging and Structural Elements


"How do I learn to speak wine?" It’s a surprisingly common question with a terribly unsatisfactory answer I’m afraid.

During all my years immersed in the world of wine I must admit to hearing this question over and over again. It’s a question without a specific answer. In fact it’s a question that can only be answered through a series of experiences.

Unlike math or English, for example, wine cannot be learned from a book. It must be experienced. In an effort to help move people along and guide them through their experiences, I am going to produce a series of articles that can serve as a study guide of sorts.

Wine is immensely complex, but as with any field of study you have to know the basic vocabulary, so that’s where we will start off on our journey. Each category of wine (white, red, rose, sparkling, and dessert) has its own unique terms, but there are some general terms that are helpful with all wines.

In order to maximize the benefits of tasting and analyzing wines it’s imperative that you keep good notes. You can find many styles of notekeeping books on the web or download one from Snooth.

The Basics of Tasting: Swirl, Sniff, Sip, and Spit (Sometimes)

In order to fully appreciate a wine it’s a good idea to get familiar with the basic steps used to taste. Swirling the wine in the glass helps to release the aromas. You taste with your nose as well as your mouth, so take a deep sniff of the wine before taking your first sip. Once the wine is in your mouth make sure to let it spread all over your tongue, reaching all of your taste buds, so you don’t miss a thing.
For our first lesson we’ll focus on the terms used to describe a wine’s structure. That simply means the acid and tannins that are found in a wine. The way a wine smells, feels, and finishes are all greatly affected by the wine's balance of acid, tannin and fruit.


There are two main types of acidity present in wine. The first, and most common, is the naturally occurring malic acid found in grape juice. This is the same acid that gives an apple its tartness.  In certain wines, such as Riesling, Chablis and Barbera for example, this intensely cutting acidity is expected and welcomed.

For most red wines, and many white wines, the malic acid is simply too much and overpowers the fruit flavors, while robbing the wine of a desirable mouthfeel. These wines are allowed to go through a second fermentation called malo-lactic fermentation. This is a bacterial fermentation, as opposed to the yeast-driven alcoholic fermentation that first created the wine. It converts that hard malic acid into softer lactic acid, which is the same acid that is found in milk.

The MLF, that’s shorthand for malolactic fermentation, reduces the impression of acidity in a wine giving it a soft, rich texture, while allowing the fruit flavors to come to the fore. It also frequently imparts a bit of buttery-ness to the finished wine, a trait that is quite popular.

Since this buttery note has proven to be appealing, particularly in the US market, many producers also choose to age their wines in new oak barrels, most frequently the 225 liter barrels known as Barriques. These can be made out of many types of wood but in general,  American oak and French oak are used. French oak tends to impart a lighter, spicier flavor that can range from light buttered popcorn to butterscotch, with strong notes of dried ginger and vanilla. The flavors are greatly affected by the degree of toasting the barrels undergo. Some toasting is used simply to help bend the barrel staves into shape; most barrels are rather assertively toasted to impart these distinctive flavors.

American oak is quite common in California, in particular for Zinfandel and Petit Sirah, Australia, and historically in Spain where it helped define the style of Rioja for the past century. American oak has a less nuanced impact on wine, adding strong notes of vanilla and coconut.

In addition to imparting flavors, oak barrels can also impart sweetness; the toasting process forms a type of sugar similar to what is created by searing meat. This sugar, while not terribly sweet, can add a sweet smell and flavor to the wine. Wood barrels can also add tannins to a wine.

Barrels have their greatest impact on a wine when they are new. In general the impact fades over the first 4 years or so resulting in what is known as a neutral barrel, one that no longer contributes significant flavors, aromas or tannins.

Tannins are contributed from the grape’s skins, stems, and seeds, as well as from barrels. Grape tannins and wood tannins can contribute a different feel to the wine and are the main strucutral element that allows red wines to age well. When they are unripe or out of balance in wine, tannins can contribute bitterness to the wine and astringency. If you’ve ever chewed on a popsicle stick you’ve felt dry, astringent wood tannins.

That’s the basic run down on tannin and acid: the structure of a wine, with a brief look at barrel aging.  Next time we’ll take a closer look at barrel ageing and the techniques used to minimize or maximize the impact of those barrels.

This is part one of a four part series.

Read Additional reports in this Series on Snooth.

Part Two: Wine 101 - Why Oak Works

Part Three: Wine 101 - Oak Structure and Seasoning

Part Four: Wine 101 - Toasty Oak and why it's not all good

Keep your notes on Snooth, but always be prepared to jot them down on the spot.

The Wine Buyer's Record Book
Ralph Steadman, the internationally famous cartoonist who rose to fame for his gonzo-artwork is now equally famous for his works on wine, such as this handy and humorous little book that makes it fun and easy to keep track of your wine tastings.

Snooth's Wine 101 Tasting Sheet
Taste wines and record your impressions as you test out the principles discussed in this lesson. Get better at identifying the notes of oak aging in wines and begin to see how a wine's balance affect its feel. This PDF is free and easy to use, so try it today.

Mentioned in this article


  • Snooth User: MDY
    142509 7

    Good article! MDY.

    Oct 01, 2009 at 1:18 PM

  • Snooth User: Marty N
    142701 11

    Hi Greg,

    As you know, love all your stuff. Keep it coming! Awaiting the long-overdue book on Piemonte.

    Marty N. (aka Dr. Marty)

    Oct 01, 2009 at 1:21 PM

  • To truly understand math or English I submit that they too must be experienced (but I'll drink to experiencing wine anyway). :-)

    Oct 01, 2009 at 2:27 PM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    Thanks MDY!

    Marty, I appreciate it. I think that book will have to start off as a pamphlet on some 20 or so producers.

    I can concede the point Charles. It certainly can't hurt, but as you hint, they may not be as much fun! And in any event, I am better at drinking than either Math or English.


    Oct 01, 2009 at 3:18 PM

  • Good basic information on MLF and tannins. Will keep this in mind the next time I swirl, sniff, and taste. Maybe I should combine this with my Math homework ... J/K.

    Oct 01, 2009 at 3:56 PM

  • Snooth User: LaHave01
    234804 1

    Good article.
    However, you mention 'toasting process' without telling people what 'toasting' means. As you know, barrels are toasted to different degrees, and some wines are aged only with toasted heads.
    Enjoy your newsletter!

    Oct 01, 2009 at 4:30 PM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    Thanks Samcat!


    That's part of the next email. Once I wrote up all the detail this email and article was just too long. I'll be discussing the barrel aging process in more detail soon.
    Thanks very much!

    Oct 01, 2009 at 4:39 PM

  • Snooth User: shari duff
    156349 18

    Not to sound illiterate, but is it the "oaking process" or the tannins that make the wine burn your throat on the way down?? Some wines almost feel like a swig of whiskey and leave you with heartburn.

    Oct 01, 2009 at 5:25 PM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    That sounds like alcohol Shari.

    What sort of wines are leaving you with this feeling?

    Oct 01, 2009 at 5:29 PM

  • Snooth User: info53
    Hand of Snooth
    92193 11

    Fantastic, and short brief for our customers.
    It will help them to understand complexity of wine and processes needed to achieve quality of wine.

    Oct 01, 2009 at 6:51 PM

  • Snooth User: Honeybells
    214185 93

    Thanks Greg! You know I've been waiting for this to come out... and I'm learning a lot! I love kept promises... and this article is just what I needed. I look forward to the follow up articles! -Bells

    Oct 01, 2009 at 6:52 PM

  • Snooth User: cigarman168
    Hand of Snooth
    227923 332

    Hi Greg, thanks for your great contribution and keep going. So good structure of wines will depend on the wine makers decide the time duration for MLF and ageing in barrel and choice of what kind of barrels. Am I close to the answer?

    Oct 01, 2009 at 10:41 PM

  • Snooth User: PaulLL
    141306 6

    Hi Greg, one very minor error in an otherwise excellent discussion: lactic acid is not a component of fresh milk; it is found in fermented milk (yogurt, sour cream, etc.)

    Oct 02, 2009 at 12:40 AM

  • Snooth User: RLV
    265766 1

    Greg this is great
    All very well finding that you enjoy some wines & and dislike others
    But makes a big difference when you get to know why you appreaciate some wines more than others - Thanks

    Oct 02, 2009 at 5:40 AM

  • This is exactly the kind of thing I've been looking for. Thanks!

    Oct 02, 2009 at 11:15 AM

  • Snooth User: shari duff
    156349 18

    In reply to Greg from my above question....alot of Cabs and some Merlots seem to leave the "burn" sensation. I love smooth French Pinot Noirs and they do not seem to do this. Does this mean that some wines have more alcohol?? They all seem to say 12% or less. Your tutelage is very informative and interesting. Please continue on, as it is fascinating. I would love to know more about the differences in European and domestic wines, and what contributes to these differences. From my little experience in trying different wines, I find the European wines way more complex and interesting in their different flavors.

    Oct 02, 2009 at 1:09 PM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    @Bells Thanks for the inspiration!

    @Cigarman Structure comes first from the tannins and acids of the grapes. MLF time in barrel and type of barrel can definitely affect the structure of the wine. I'll focus more on that in my next installment.

    @Paul, Your are absolute right. I should point out that it's the acid that forms in milk as it spoils, intentionally or not! Thanks for pointing this out.

    @RVL I hear you.

    @Shrimp I'm glad to know people find it useful!

    @Shari Very few wines have 12% or less. In fact almost all wines now have over 13% and in warm regions 14% as a base is not an unreasonable guess. I'll circle back with a more complete answer to this but I'm guessing that there might be a blend of alcohol, tannin, and acidification that's the culprit here.

    Oct 02, 2009 at 5:02 PM

  • Snooth User: Alan H
    260148 1

    Greg - thank you for the article and I look forward to more. I am new to Snooth but, from what I have seen and read, believe I have found kindred spirits here.

    I really enjoy understanding the variables and complexity of the chemistry that raises winemaking to an art and wine tasting to art appreciation.

    Oct 02, 2009 at 9:39 PM

  • Snooth User: shari duff
    156349 18

    Thanks Greg, I will have to pay more attention to the ones I am drinking that have this problem for me. I find this fascinating and am looking forward to learning more. I am not a bottle reader and will have to notice the fine print more. The one I currently use as my "house favorite" is 13% and a French Pinot Noir.....inexpensive, but enjoyable. Kudos to your exceptional knowledge and great way of conveying the info so it is easily understood.

    Oct 03, 2009 at 1:55 PM

  • Snooth User: Philip James
    Founding Member Hand of Snooth Voice of Snooth
    1 12,573

    19 comments - thats a record for comments on an article. The Snoothers have spoken, there will be more Wine 101 articles to come.

    Oct 03, 2009 at 3:12 PM

  • Snooth User: phlop
    257346 4

    Great Article! As an 18 year old who is just getting in to wine, I find articles like this very helpful. Thank you!

    Oct 05, 2009 at 1:11 AM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    Welcome Alan H, I'm glad you found us!

    Hey Shari,

    One thing to keep in mind is that various countries have various level of specificity regarding alcohol on the label. In the US a bottle can be labeled "11%-14%", or conversely can be labelled as 12.5% and actually contain anywhere from 11 to 14% alcohol. Thank you for the kind words. I'm just trying to make wine easier to understand and more enjoyable for all.

    Thanks Phlop!

    Oct 05, 2009 at 8:25 AM

  • Shari - would you be willing to share the name of that French Pinot Noir you refer to? Pinot is my favorite red wine, but I don't like ones that have what I refer to as an intense 'cherry cough syrup' flavor. What is your 'house favorite' French Pinot?

    Oct 05, 2009 at 2:16 PM

  • Snooth User: shari duff
    156349 18

    In reply to catsnorchids, It is called D'Autrefois Pinot Noir (says Alfio Moriconi Selection on bottle) plain white label and in Florida it is $10 a bottle. It has been consistently good from 2007 thru 2008. Not a pricey wine, but I love it and have had lots of compliments on it when served to guests....hopefully they are sincere LOL

    Oct 05, 2009 at 10:05 PM

  • Snooth User: Piccolo161
    199543 37

    Thanks for the article Greg.
    I also clicked through to the article on tasting etiquette which I found useful too.
    It's good to have some translation of wine language which I call ' wine-ese' and sometimes find as difficult to understand as chinese

    Oct 07, 2009 at 5:22 PM

  • Snooth User: Gregory Dal Piaz
    Hand of Snooth Voice of Snooth
    89065 236,475

    That is indeed the case Piccolo!

    I recently posted a response in a thread on wine ratings in the Snooth forum that started off with a rather nonsensical intro. It's what I think a lot of people hear when we start talking about wine!

    Oct 07, 2009 at 6:15 PM

  • Snooth User: solomania9
    Founding Member Hand of Snooth Voice of Snooth
    6331 2,962

    Looking forward to the rest of the series. Very helpful!

    Oct 13, 2009 at 5:29 PM

  • Hey Greg,

    Your article was great. Keep it coming.


    Oct 15, 2009 at 5:17 PM

  • Great Article and comments. Keep them coming. Anyone has good links for setting up a wine cellar. And recommendations of what red wines worth to collect for the next 20 yrs. Just bought a house with an empty cellar. As a beginner wine drinker love to hear from you experts out there..

    Oct 15, 2009 at 11:24 PM

  • Snooth User: joeshico
    204703 71

    I never understood the nuances of different oak.
    Thanks for the lesson! Keep 'em coming.

    Oct 15, 2009 at 11:59 PM

  • Snooth User: info168
    Hand of Snooth Voice of Snooth
    193493 44

    We are using American Oak barrels for 4 years now instead of French and we are very satisfied with the result.

    The article about basic tastings is a perfect guideline well explained.

    Oct 17, 2009 at 9:07 AM

  • Snooth User: spun69
    Hand of Snooth
    274208 68

    Nice article, looking forward to next in the series.

    Oct 17, 2009 at 10:31 AM

  • you article was good, looking forward in the series very helpful

    Oct 17, 2009 at 3:15 PM

  • Snooth User: amour
    Hand of Snooth
    218530 2,203

    YOUR PIECE REMINDS EVERY WINE LOVER HOW LUCKY WE ARE TO HAVE SUCH A STIMULATING PURSUIT....always so much to learn, assimilate, the wine itself!!!!
    CHEERS ....WITH A LA TACHE,of course!!

    Nov 03, 2009 at 2:19 PM

  • Snooth User: ProfPayne
    260721 34

    excellent article! very helpful, and I like your wine tasting sheet.

    Nov 07, 2009 at 10:53 AM

  • Man, you keep up this kind of quality writing and you'll put a lot of wine educators out of business. :-)

    Dec 02, 2009 at 5:44 AM

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