Boysenberry Wine—Grape Wine is also a Fruit Wine!

I’m lucky to live in Southern California, where I can get access to some incredible wine grapes. But wine grape activities take place in the autumn for picking, crushing, fermenting and pressing. Then they go into the barrel, and there’s not a whole lot to do until bottling time. In the winter and spring, I like to make some wonderful fruit wines! But before you go and say “harrumph” to fruit wine, remember – grape wine is also a fruit wine!

These pictures show my 2021 Boysenberry wine, from berries grown by my brother David in Boise, Idaho. As is only obvious, I named it my Boiseberry Wine!  Since my brother grew them and we share our last name, can I call it Donnelly Estate Wine? Oh hell yes!

Unlike grapes which can usually be harvested in one picking, boysenberries are hand-picked one at a time over a two-month period, so Dave and his wife Michele picked the berries between July and August, and froze them as they were picked.

When he had enough for a batch of wine (and a few more pounds for ice cream – YUM!), he shipped them down to me. I started the batch on October 5th with 23 pounds of berries for a 6-gallon batch.

After sanitizing everything, I added the berries and water into a 7-gallon food-grade bucket (no Home Depot buckets).

One habit I use with fruit wines is that I buy and use quality bottled drinking water to bring it up to 6 gallons; I don’t use tap water.

If you remember the old Hamm’s Beer, they had an animated bear in their commercials. Their slogan was, “It’s the water that makes the difference!” I’ve always taken that advice to heart, whether I’m making wine or beer.

I then added about 11 pounds of sugar to bring it up to my target of 25 brix (25% sugar), added about a gram of potassium sulfite as a preservative, and pitched Red Star Premier Classique yeast. Hint here: use the stirring tool with an electric drill to save you a lot of time and elbow grease stirring, to dissolve the sugar!

The “must” (unfermented wine) takes about 2 weeks to ferment while the sugar changes into alcohol. During this process, the fermentation causes a bi-product of Carbon Dioxide, which is seen here with the bubbles.

Once the 25% sugar has fermented down to zero (the hydrometer actually reads slightly below zero), I will have wine with about 14% alcohol, right in the range of a typical California red wine.

After the fermentation is done, I use a strainer to separate the solids from the wine, and I transfer the wine to a carboy and top it off to 6 gallons with water. There are still a lot of solids in suspension in the wine, but as it sits and ages in the carboy, most of those solids precipitate to the bottom, and I can “rack” (siphon) the clearer wine off the top, and toss the solids.

After about 2 months and a couple more rackings, I filtered my Boysenberry Wine, and it’s BEAUTIFUL, with a transparency and maroon color you have to see to believe!

But it’s pretty tart, since all of the sugar has been turned into alcohol, and the boysenberry flavor is muted! Next up: back-sweetening it. The term “back-sweeten” means to add sweetener, usually sugar, after fermentation: the back-end of the process. Here, I typically sweeten by about 3%, which brings back the unique qualities of boysenberry flavor, similar to blackberry, but with more bite.

Some people like to add more sugar to make a sweeter dessert wine, but I prefer to make my fruit wines in a table-wine style, and not much perceived sweetness. That way, it makes for a WONDERFUL aperitif before dinner, and a refreshing beverage on a hot afternoon!

Before I can add sugar to back-sweeten, I need to stabilize the wine, so it won’t start re-fermenting.

Commercial wineries do this by cold-stabilizing their wines. If you’ve visited a commercial winery, you may have noticed a ring of frost around their stainless-steel tanks. By reducing the temperature down to the mid 30 degrees, they are neutralizing the yeast. But glycol chillers cost several thousands of dollars, and since I’m a cheapskate, I don’t have one.

I use potassium sorbate and sulfites to stabilize the wine before I add more sugar, to prevent the residual yeasts in the wine from acting with the additional sugars.

To decide how much sugar to add to back-sweeten the wine, I set up a bench test. This process involves setting up several different samples of wine with increasing quantity of sugar. I now taste the wine, sometimes with friends who NEVER say no when offered wine, for their opinions. (Dave and Michele, come down from Boise and taste this wine!) I may or may not take their advice – it’s MY wine! Well yea, it’s Dave and Michele’s wine too …

I pour one glass with no additional sugar. The 2nd glass has ½ teaspoon of sugar. The 3rd glass has 1 teaspoon of sugar, the 4th has 1½, and the 5th has 2 teaspoons. I then taste, and decide which is my favorite; often “it’s between 3 and 4”, so I pour another glass with half the increment, and choose.

Once I have picked my favorite, I measure the brix with a hydrometer of the chosen wine, which usually reads somewhere between 2 and 4 brix. The unsweetened wine measured below zero, -1.5 (Specific gravity -0.994). After my bench testing, I chose #4, 1½ teaspoon of sugar, which measured Brix of +1 (or Specific Gravity 1.08), which equates to adding 2½% sweetening.

That becomes my target brix, +1, to back-sweeten the entire batch.

Remember that when you add sugar, creep up on the target, adding a little at a time. Don’t add one large addition. You can add more sugar, but it’s hard to take it out if you over-shoot the target.

I ended up adding about three cups of sugar to reach my desired flavor: not overly sweet, still a little tart. Again, during this process, using a stirring tool and a drill will save you a lot of time!

Now that I have my wine sweetened to my taste, it’s time to bottle and wrap up this project. I now have about 5½ gallons of Boiseberry Wine. One gallon of wine fills five standard bottles, so I’m estimating that I’ll need 28 bottles. I always prepare a few extra, so I’ll sanitize 30 bottles.

The wine supply stores sell two different kinds of bottle corking machines. The cheap ones are about $20, but they are difficult to use. I recommend getting a floor corker, which starts around $70. This corker will save you time, effort, and maybe even avoid some spills.

After corking your bottles, it’s time to spruce them up! We do this with bottle toppers that resemble the foil on the top. These are available in different colors, and are shrink-wrap plastic. You can buy an expensive heat gun for about $180, or you can just dunk it quickly into boiling water for almost no cost. Hey, we’ve already established that I’m cheap, right?

The last thing to do to make your bottle pretty, is to put on a label. I’ve named my amateur winery “Donnelly Micro Micro Winery”, because I’m really, REALLY small! I also put on the varietal, the date picked and the date bottled, and some other info of interest to fellow winemakers, such as yeast and residual sugar.

I like to use clear colorless bottles, to show off the beautiful color of the wine.

You will have a wonderful beverage to share with your family and friends, and they make great gifts any time of the year!

– Kevin Donnelly, Winemakers’ Group

The article is also available on the WineMaker Magazine website, titled “Boysenberry Wine: My Out-of-Season Winemaking Adventures.”