Wine and The Mysteries of Sugar & Sulfites

Issue #39, June 2022

In the last few months, I’ve found myself in a few conversations regarding two controversial ingredients that are in the wine we quaff. Sugar and sulfites. I know you’re probably thinking this guy needs to find more interesting things to talk about. You’re right, but in the mean time I thought we should bring these two rascals to the cellar. I’m no, Bill Nye The Science Guy, but I’ll do my best to make sense of the two S’s. 

So, put on your lab coats and get comfortable around the old, oak tasting table while we fill our beakers with a little viticultural science and of course, three delicious and affordable wines to wash it down with.

Welcome back to the cellar.

I’ve flipped a cork to decide which ‘S’ we’ll tackle first. It’s come up Sulfites. 

Most bottles we pick up at the LCBO have a little poetic disclaimer on the back that goes something like this; ‘Contains sulfites’. 

Of course, this is hardly appealing and many of us wonder why it has to be?  “We don’t need no stinkin’ sulfites.”

Well actually, there is no way around it. Unless heaven forbid, we don’t drink wine. Wine is fermented using yeast, which naturally produces sulfites, so almost all wine contains them. However, most winemakers do add sulfur dioxide (sulfites) in their winemaking process. They do so to protect against oxidation, to prevent the growth of unwanted micro-organisms and to preserve colour. Basically, sulfites are preservatives and antioxidants that keep bacteria from ruining the wine and significantly increasing its shelf life. 

What if you don’t want any added sulfites?  In the United States, wines labeled as organic cannot contain added sulfites. Naturally occurring sulfites must not exceed 10 parts per million (ppm). So, is organic wine the answer? Yes. Well sort of. Because some wines may be labeled, ‘made with organic grapes.’ Which means they may have sulfites added later during processing. And I have yet to see a bottle that states ‘no sulfites added’.  

In Europe and Canada organic wine is defined as wine made from organically grown grapes which also may contain added sulfites. The reality is, they’re as tough to avoid as black flies in May. 

Look for organic wine that clearly states, ‘no sulfites added.’ Or look up the winery that makes the juice you’re interested in and see what they have to say about their process. 

Bonterra Organic Vineyards of Mendocino County, California produces 100% organic and biodynamic wines. I spoke with someone at the winery who told me they do add small amounts of sulfites to their wine but lower amounts than most wineries.  

Bonterra Organic Cabernet Sauvignon
California, USA
VINTAGES# 342428

This wine is a blend of grapes, predominantly Cab Sauvignon. It has aromas of fresh cherry, currants and raspberry and vanilla. In the glass, you will find flavours of cherry, mocha and currants. 

It has a fair bit of flavour for sure. So, if you want an organic wine you can bet your Birkenstocks on, this is a good one to spend some time with.

Now it’s on to our other guest ingredient; Sugar. 

The truth is, sugar found in grapes is at the heart of what makes winemaking possible. Without it, we simply would not have wine. Ripe grapes naturally contain sugars but some grapes are naturally higher in sugar than others. For example, the Zinfandel (Primitivo) grape has more natural sugars than Pinot Noir.

When the juice of grapes is turned into wine, most of the sugars are converted into alcohol through fermentation. But some sugars remain after the fermentation process is complete. This is called residual sugar and it’s the primary source of a wine’s sugar content. 

Generally, the residual sugar content after fermentation is inversely proportionate to alcohol level. So, higher alcohol wines have less sugar, and lower alcohol wines have more sugar.


If the winemaker stops the fermentation process early, the wine will have higher amounts of sugar and less alcohol. If they ferment longer, the wine will have lower sugar and more alcohol. C’est ca.

Low-sugar reds to look for are Pinot Noir, Cabernet Sauvignon, and Syrah/Shiraz. Low sugar whites are Pinot Grigio, Sauvignon Blanc, Chardonnay, and Viognier.

We took our sweet time about it, but let’s have our second glass of wine; a white featuring one of those aforementioned less sweet grapes; a very nice Pinot Grigio from New Zealand. 

Oyster Bay Pinot Grigio
Hawkes Bay, New Zealand
VINTAGES# 326090

Sugar Content: 4 g/L,

Pinot Grigio, also known as Pinot Gris is of the species Vitis vinifera. (Have I been blinded by science?) I read that Pinot may have been given its name because it grows in small pine cone-shaped clusters.

This Oyster Bay Pinot Grigio is floral with tastes of lush grapefruit, yellow plums and refreshing minerality. Perfect for sipping on a hot summer afternoon while brushing up on the periodic table of the elements. 

Moving on. 

Another bottle has been patiently waiting to catch our attention. This is a delicious red that features another low sugar grape; the temperamental yet classy Pinot Noir. This of course is the great grape of Burgundy. But it also seems to quite like the idea of growing in Oregon.  

Underwood Pinot Noir 2020
Oregon, U.S.A.
VINTAGES# 421198

Sugar Content: 2 g/L

Pinot Noir’s thin skins and low phenolic compounds (that’s my inner scientist talking again) produce mostly light-coloured, medium-bodied, low-tannin wines. But they can be the most flavourful wines made. 

The Underwood Pinot Noir before us comes bearing elegant flavour gifts of cherries, currants, mushrooms and forest floor after a rain; an enchanted forest for sure. 

In case you couldn’t tell, I like this wine.

Okay, well there we go. Although the cellar isn’t much of a laboratory, I hope you enjoyed our study of the two S’s. And our discovery of three more wines that feature the third S: scrumptious.

See you in July when for very special reasons, we’ll do a deep dive into Champagne, Prosecco and Cava. If anyone has any faves, let me know.

Until next month, keep your glass of wine close and your friends even closer.


Thanks to everyone for signing up to my web page where you’ll see this each month as a blog. If you know anyone who is interested in following the newsletter, they just have to visit to submit their email. They’ll be notified each month, as will you, when each new issue is published. And the newsletter is a little more reader-friendly there. Please let me know if you’d like to share some wine you love with the rest of us. 

4 thoughts on “Wine and The Mysteries of Sugar & Sulfites

  1. The longer the fermentation, the less sugar and higher alcohol content. Great news for a type 1 Diabetic! That’s what I call serendipity.


  2. Thanks Jim….nice read and educational at the same time. Does Loretta actually write these? J😊

    This e-mail or document(s) is being shared in trust.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s