Welcome to the World of Winemaking! I’m having fun alphabetizing the home winemaking process – here are the links going backwards for your convenience, in case you missed any:

A for Aromas, Acidity and Appearance
B for Barrels, Bottles and Blackberry Wine
C for Color, Clarity, Carboys and Cherry Wine
D for Decanting and Decanters
E for Equipment
F for Fermentation
G for Glass and Grape

Today’s letter is “H”, so we’ll talk about Harvest! 

I read this description about harvest and winemaking somewhere, and I totally agree:

Sports teams have playoffs. Students have finals. And for winegrowers, the big sink-or-swim moment – the event the whole year’s efforts have led up to – is harvest.

There is a whole educational part of learning about geography and knowing where and how to grow grapes, but the next most important decision in the winemaking process is knowing when grapes are ready to be harvested.

It’s certainly one of the fun parts, as it’s a combination of science and instinct on the part of the winemaker. I had so much fun monitoring the grapes growing on the scads of vines I planted on our property in Pennsylvania – keeping an eye on the grapes and the amount that they dry on the vine has a direct impact on the sugar content, which defines many characteristics for wine, especially the alcohol content.

For most of my friends who drink my wine, alcohol content is important…heh!

With so many varieties of grapes around the world, there’s always a harvest going on somewhere. Generally, wines are harvested from late August until early November in the northern hemisphere, and between February and April in the southern hemisphere. For some white grapes, and in some cool areas in the southern hemisphere, harvesting can extend into May, and those regions that produce ice wines can begin as early as January.

Late harvest refers to wines made from grapes that are left on the vine longer than usual and generally yield a sweeter wine. Wine is harvested in two ways—either by hand, or using machinery. Obviously for the home winemaker you’re going to harvest your grapes by hand – or order the grapes from a local winery that sells them to the home winemaker, or buy them in bulk from your favorite grocery store.

When growing your own vines, it’s a tricky process to keep an eye on the grapes and make sure you don’t pick them too early – or too late, as either of those scenarios will directly impact the sugar content. As mentioned in the Fermentation post, sugar content of the grapes is important, since that’s what converts into alcohol.

Weather is a major factor in deciding harvest time. Sudden weather changes can have an impact on the drying process on the vine, particularly as you get closer to harvest time. For example, if you think of grapes as pre-dried raisins, you can imagine that as the fruit dries, water evaporates.

If sudden rain storms arise at harvest time, the additional water raises the water level in the grape, reducing the amount of sugar. If the winemaker waits too long, or the conditions have been dry that season, there may be too much sugar, reducing the acidity. This can affect the taste and the aging potential of the wine.

With all of that being said, more and more winemakers are making their decisions based on producing taste. Thus, experience and instinct rule the day! Not to mention that you can walk around your rows of grapes and snack on them to see if they taste ready to harvest.

Certain grapes are sensitive and require extra TLC – for example, white grapes are thin skinned and fragile and can be very sensitive to changes caused by weather and in the soil, especially Chardonnay. As you monitor the ripening of your grapes, you can test the sugar with a refractometer, or simply by eating them. Trust your palate – or, while on your learning curve, pick up a refractometer like I did to measure sugar content in the grapes:

It’s a cool tool that we’ll go more into detail later in this series, but the gist of it is that you put a couple of drops of juice from one of your grapes and look through the eye piece while aiming the tool towards a bright light source, and you can read the sugar content of your grapes. Pretty nifty, no?

The period culminating in grape crush begins when the grapes start to change color in mid to late summer.

When it’s time to harvest, keep in mind that the time of day you pick the grapes is just as important as the time of year. Harvesting at night ensures a stable sugar level in the grapes, something that fluctuates when the temperature rises. 

If you prefer not to be out harvesting your grapes in the dead of night like the big wineries do, do what I do and go out in the wee hours of the early morning before the sun rises and starts to heat things up. Bonus – you can enjoy a nice sunrise!

Depending on what kind of grapes you have planted (or how many varieties), collecting grapes can take several months because the optimum ripeness varies from varietal to varietal. For instance, white grapes like Sauvignon Blanc are picked first because you want lower sugar to acid ratios to give those wines a crisp, almost tart taste.

Red grapes are picked later and grapes for dessert wine, like “late harvest” Riesling, are left on the vine even longer so the fruit continues to ripen, i.e. produces more sugar, resulting in a sweeter wine.

One of the important steps of your harvest is sorting through all the grapes you’ve picked. You want to check for mold and other imperfections, keeping only the premium grapes for your winemaking. I usually do that as I de-stem the grapes, tossing the icky grapes and filling up my fermentation bucket with the good ones.

You can either rent or buy a de-stemmer – eventually I’ll get one, once I’ve planted vines at our new house that will warrant needing to speed up the process of de-stemming:

There are several popular machines used in the de-stemming process. You can get one that is strictly a de-stemmer (which is what I’d prefer – I’d rather do the manual crushing to make sure I’m getting the best out of my grapes), but you can get a combination crusher/de-stemmer.

Both types are like a giant auger (think large cork screw) that separates the grapes from the stems, sending the stems one way and the grapes in the other. The combination crusher/de-stemmer smooshes (to use a technical term) the grape bunches along a stainless steel valley, squeezing out the grape juice while pushing the stems and other bits to the end of the device where they can be removed.

Winemakers can thank Lucille Ball for glamorizing the crush during her iconic grape-stomping escapade in I Love Lucy.

Lucy would be disappointed at her prospects today, as most human grape-stompers have been replaced by the aforementioned de-stemmers/crushers. 

Whether red wine or white, intuition or science, one thing to remember as you enjoy your next glass of wine is that there’s a lot of work that goes into ensuring that the taste, texture and color are just right.

Winemaking is so much fun – at least for me – and am tickled every time I give the wine I make as gifts to friends and family who love drinking it as much as I love making it. While we go through this alphabetical series on winemaking, if you have any burning questions, be sure to ask them in the comments below, and I’ll reply there – and maybe even highlight your specific question(s) in a future post!

Thanks for joining me in this fun adventure!


  1. Stacy, I’d like to grow grapes someday but not for winemaking just eating. 🙂 My in-laws had a small vineyard and we always looked forward to getting homegrown grapes because they are the best. You just can’t buy good tasting grapes in the grocery store. DH’s uncle has a larger vineyard and he sells grapes to the locals relatively cheaper in my opinion. I’m not sure if he’s still doing this or not but if we manage a trip back this summer then we need to get us a buck. I don’t think we’ll have too many opportunities to enjoy this with an elderly FIL and the uncle getting on in years, too. It’s sad to see those we love getting older and leaving us. Thanks for sharing the Lucy grape stomping photo. I always enjoyed watching the I Love Lucy show! Stop in to visit today’s post, #AprilA2Z Art Sketching Through the Alphabet Letter “H” + #4M whenever you get a chance!

  2. The process sounds def requires patience! I did appreciate the instinct winemakers cultivate the longer they tend to their vineyard(s). Pretty nifty!

  3. Very interesting process! My Dad and his friends are hobby wine growers, so I know how much work is involved just so people like me get to enjoy a glass.
    I love how you compare harvesting the grapes to the hockey play-offs!

Comments are closed.