What’s in a Wine Kit?
I see a lot of questions regarding what is in a “wine kit”. I’m offering my take on subject, both in terms of description and why each is necessary.
First — what is a “wine kit”? In short, it’s a package containing the consumables necessary to make a batch of wine, typically a nominal 23 liters (6 US gallons), although some kits are 12 liters (3 US gallons) or 4 liter (1 US gallon). The most common kits reconstitute to 23 liters, so my comments are pointed at that size kit.
What kits don’t include is hardware — kits do not normally contain fermenters, carboys, siphoning equipment, corks, or bottles.
Kits advertise that wine is produced in 4 to 8 weeks. This is an accurate statement, as it’s totally feasible to produce and bottle wine in 4 to 8 weeks. The wine isn’t ready to drink at that point, but it certainly can be bottled. The contents of kits are designed to ensure the wine can be bottled in the indicated timeframe.
Note: In traditional winemaking, the time from start to bottling is typically 4 to 24 months, so bottling quickly (1 to 2 months) requires special measures. Kit vendors have gotten good at condensing the process to a short time frame. However, to make this happen, the instructions must be followed.
Kits may contain the following items, although the exact list varies depending on wine and the vendor.
- Juice/Concentrate Bag — contains a mixture of grape juice and/or grape concentrate. Concentrate requires adding water to reconstitute to the kit’s stated volume.
- Bentonite — this is a type of clay, a fining agent that helps the wine clear; not present in all kits.
- Fermentation Oak — oak dust or chips added prior to fermentation; not present in all kits.
- Skin Pack — dried grape skins added prior to fermentation; not present in all kits.
- Carbon — used in some kits to reduce browning in light colored wines; not present in all kits.
- Yeast Nutrient — used in some kits to provide proper nutrition for yeast. Most kits have this mixed into the juice/concentrate, but some provide it separately.
- Yeast — eats sugar and emits alcohol and CO2. No yeast, no fermentation.
- Kieselsol & Chitosan — two fining agents commonly used in conjunction to quickly clear a wine, e.g., remove sediment.
- Aging Oak — oak chips or cubes added post-fermentation; not present in all kits.
- F-Pack — a “finishing” or “flavoring” pack, included in some wines to backsweeten and/or add a flavoring; not present in all kits.
- Potassium Sorbate / Finishing Pack — sorbate is birth control for yeast, which prevents a renewed fermentation in the bottle if there is any remaining sugar.
- Potassium Metabisulfite — commonly abbreviated as “K-meta”, this is a preservative and anti-oxidant that kills/stunts unwanted microbial life and greatly extends a wine’s shelf life.
These items are used to produce the “must”, the substance that will ferment to produce wine. The last item added is the yeast.
The contents of the bag depend greatly on the wine type and quality of the kit. In the past, the higher quality kits contain a higher ratio of grape juice to grape concentrate (meaning the bag volume was larger), and were more expensive. However, recent advances in grape juice concentration techniques changed this, so volume is not necessarily a valid measure of quality, nor is price.
A few years ago Winexpert changed their concentration process and started shipping smaller volume kits, while maintaining or exceeding the quality. More recently, Finer Wine Kits uses unpasteurized concentrate which is high quality, at a lower price. These product changes make it difficult to look at the kit volume or price to make a quality decision.
I recommend reading reviews and opinions regarding kits.
I have enjoyed success with Finer Wine Kits, Winexpert, and RJ Spagnols kits. I do not have recent experience with other vendors, and offer no opinions, positive or negative.
Note 1: A common tactic is to “short” the water when reconstituting a the juice/concentrate, e.g., reconstituting to 21 liters instead of 23 liters. This produces a higher initial specific gravity (SG) and concentrates the materials that constitute body. This also increases the acid level, which can throw the wine out of balance by making it sharp. IMO, if buying a good quality kit, it should be reconstituted to the manufacturer’s specified volume.
Note 2: A 23 liter kits reconstitutes to 23 liters (6 US gallons). In theory this produces thirty 750 ml bottles of wine. However, in practice, less bottles are produced, as volume is lost due to sediment (solids) in the wine and losses during racking (siphoning off sediment). This is totally normal and expected. This post explains tactics for reducing volume losses during racking.
Bentonite is a negatively charged fining agent which attracts positively charged particles and settles out, clearing (fining) the wine. Many kits include bentonite in the initial reconstitution of the juice/concentrate. Many consider it difficult to work with, as it needs to be dissolved in hot water, which requires hard stirring.
This is added for several reasons:
- fining agent — it helps with the speedy dropping of fruit solids and yeast hulls.
- protein haze — if the wine has a protein haze, bentonite eliminates it.
- nucleation site — bentonite acts as a nucleation site for CO2, which speeds up the degassing process.
- stabilizes fermentation — reduces the likelihood a vigorous fermentation will overflow the primary fermenter.
Most kits contain bentonite, but not all.
Many red kits and some white kits (typically Chardonnay) will include oak dust, shreds, or chips which are added during reconstitution. This is “fermentation” oak, as it is removed at the first racking which occurs post-fermentation.
Dust, shreds, and chips have more surface area than other oak products, such as cubes, staves, and spirals, so it is used during the short fermentation period. More surface area provides for more extraction from the oak.
Fermentation oak imparts little or no oak character or flavor, but provides tannin, called “sacrificial tannin”. Some tannin normally drops as sediment, and the oak tannin drops in place of grape tannin (there are many types of tannin), which preserves the preferred grape tannin. Hence the name “sacrificial”.
Oak also helps impart more body and preserve color, so red wines fermented with oak generally have more color. Here is a comparison of oak adjuncts.
Some red kits include skin packs, which are packages of dried grape skins. Most red wines get their color from the skins, along with aroma, flavor, body, and tannin. While the juice extraction process from the grapes does a pretty good job of extracting the desired constituents, the addition of grape skins during fermentation improves all of the mentioned components. Wines fermented with skin packs are noticeably different from the same juice/concentrate fermented without skin packs, having more body and color.
Note: I recently learned that some kit vendors use a “skin pack” that is more like grape jam, which contributes significantly to the initial SG.
Finer Wine Kits now includes a carbon pack in white wine and lighter fruit wine kits. This addresses “browning”, a type of oxidation that makes lighter wines darker than normal. While most kits don’t exhibit this problem, Finer Wine Kits do as their concentrates are not Pasteurized, and are not shelf stable, e.g., the wine must be started immediately upon receipt of the kit, or the concentrate bag must be refrigerated or frozen.
When adding it to the primary hold the packet just about the must and pour slowly and gently, to avoid making a carbon cloud. My experience is that while the carbon initially turns the wine black (which is very odd looking), it settles out during fining (see Kieselsol & Chitosan below) and produces no negative effects.
Although most vendors mix nutrient into the juice/concentrate, Finer Wine Kits includes three separate packets:
- Packet A — first nutrient dose for the must
- Packet B — nutrient for the yeast starter
- Packet C — second nutrient dose for the must
The Packets A is added during reconstitution, and Packet B is used in creating a yeast starter. Packet C is added 48 hours after inoculation to provide the yeast with a nutrient boost.
Yeast is a single-celled fungus that eats sugar and emits alcohol and CO2. It is what turns juice into wine (or beer), and also produces the leavening in bread. Without yeast, nothing happens. Note that there are many types of yeast, and winemaking uses a small grouping of yeasts that produce beneficial results, e.g., they produce good wine.
Most kits include Lalvin EC-1118, as this strain is fast growing, has a high alcohol tolerance, and stomps out competitors (other yeast strains and other types of microbial life). EC-1118 is the closest thing to a fool-proof yeast, and helps ensure that beginners with no experienced help will produce a successful result every time.
There are dozens of commercial yeasts available, and some kits include other strains. For beginners, it is best to use the yeast included in the kit. After producing a few successful batches, branching out and trying other yeasts may be considered.
Note that each strain of yeast has different traits, such are promoting aroma, flavor, and/or body.
Kit instructions often state to rehydrate yeast in warm water, or simply sprinkle it on top of the must. I recommend creating an overnight starter, which produces a strong colony prior to inoculation.
Aging / Bottling Ingredients
The remaining ingredients are added post-fermentation.
Although this post is focused on kit ingredients, I include a few comments regarding method, since method is tied to some ingredients. All of the following ingredients are added after degassing.
Degassing: There are numerous ideas floating around regarding degassing. In my experience, “degassing” is not an immediate thing — there is no reasonable amount of stirring that fully degasses a wine, nor is there a way to immediately determine degassing is “complete”.
My recommendation is to use a drill-mounted stirring rod. After fermentation is complete (SG <= 0.998 and stable for 3 days), stir the wine in one direction for 30 seconds, then change direction and stir for another 30 seconds. This will NOT completely degas the wine, but it jump starts the process and expels a large amount of CO2. Degassing will continue for several weeks.
If you don’t have a drill-mounted stirring rod? Stir well with a large spoon or paddle for three minutes, changing direction every minute.
Note: To bottle on kit schedule, degassing is required; it’s not optional. Failure to degas will result in sediment in the bottles, and with wine may contain excess CO2, which can blow corks.
That said, I do not bottle on kit schedule. Generally white and fruit kits are bulk aged and bottled 4 to 6 months from start. Reds are bottled 4 to 12 months after start. Bulk aging the wine longer ensures it is clear (no sediment in the bottle), and produces a more consistent wine.
However, I manually degas all wines to reduce clearing time, as dissolved CO2 holds sediment in suspension.
Kieselsol & Chitosan
Kieselsol and Chitosan are fining agents that work very well in conjunction with each other. Kieselsol is negatively charged particles and is added first, followed by a good stir. Chitosan is positively charged and added later, also followed by a good stir. Typically sediment starts dropping within hours and the wine may appear clear immediately. However, it’s best to wait 1 to 3 weeks before racking to ensure the wine is truly clear.
One benefit of using these fining agents is the removal of most materials that produce a haze in the wine. One thing they don’t remove is pectin haze, which requires the addition of pectic enzyme. However, pectin haze should not occur in kits, so this should not be a problem.
There is controversy regarding how much time must pass between adding the kieselsol and chitosan. I’ve been make kits for twenty-five-plus years, and have seen directions stating everything from add both at the same time, to add chitosan 1 minute after kieselsol, to add chitosan after twenty-four hours.
Based upon my experience, I add the kieselsol and stir very well. This is done immediately after the degassing stirring. Wait one to five minutes, then add the chitosan and stir well again.
If bottling on kit schedule, kieselsol and chitosan are not optional. As with degassing, failure to use them will result in sediment in the bottle. If bulk aging longer they are optional, although usage helps ensure no sediment in the bottle. In my experience most wines clear naturally in about 4 months, but the time frame can be as long as 12 months. There are no guarantees.
Aging oak is oak products added after clearing the wine, which remain in the wine for the duration prior to bottling. In kits this may be chips but is more likely to be cubes. The oak imparts aroma and flavor into the wine.
Given that the aging oak is in the wine longer, it imparts far more flavor and aroma than fermentation oak. If bottling on kit schedule, follow the instructions.
If bulk aging longer? Leave the oak in for the duration. I have left oak cubes in a wine for 12 months — after ~3 months the cubes are expended, so the additional time does not harm. I avoid racking unless absolutely necessary, and removal of oak is not a reason for me.
Warning: be cautious of adding more oak than is supplied in the kit. It is very possible to over-oak a wine and render it undrinkable.
Depending on who is asked, this is a Finishing Pack or a Flavoring Pack. The exact name doesn’t matter and the generic term “F-Pack” is typically used. [Note that “finishing pack” has a new definition, see below.]
The F-Pack typically contains sugar for backsweetening, a small amount of sorbate to prevent the F-Pack from fermenting on its own, and may contain a flavoring. Dessert wines and wines with a flavoring (e.g., “fun wines” such as Island Mist which have a fruit flavor) include an F-Pack.
Dry red and dry white kits don’t include a F-Pack.
Follow kit instructions regarding the F-Pack. The Potassium Sorbate / Finishing Pack must be added with the F-Pack to prevent a renewed fermentation of the sugar in the F-Pack. The amount of sorbate in the F-Pack is not sufficient to prevent a renewed fermentation after the F-Pack is added to the wine.
Potassium Sorbate / Finishing Pack
Potassium Sorbate, in conjunction with Potassium Metabisulfite (K-meta), is birth control for yeast. It prevents yeast from reproducing. Note that this does not stop an active fermentation.
Kits used to include separate sorbate and K-meta packets. In recent years, kit vendors have combined these into one, which is referred to as a Finishing Pack.
As a winemaker, I find the practice irritating, as I don’t add sorbate to most wine (I make mostly dry wines). It is necessary only if backsweetening the wine.
As a kit vendor? The practice makes perfect sense.
A significant percentage of wine kit customers are beginners who have no experience nor do they have experienced assistance. They are completely on their own, just the customer and the instructions in the kit. The novice probably doesn’t have a hydrometer, so the steps in the instructions are based on duration.
As an experienced winemaker, basing fermentation on duration is a poor idea compared to checking SG. Duration may work most of the time, but is not guaranteed.
However, for the novice, fermentation normally completes within two weeks, and adding sorbate + K-meta to a completed or slowed fermentation ensures the ferment is done. The customer will not experience a renewed fermentation in the bottle, which is great as bottle ferments produce 25+ miniature purple or yellow volcanoes. Yeast produces CO2 and it blows the cork and sprays wine all over.
If you do not have a hydrometer or are adding an F-Pack, add the Finishing Pack. Failure to do so is likely to produce those mini-volcanoes, especially in the case of a F-Pack.
If you are not adding an F-Pack, have a hydrometer, and the SG <= 0.998 for 3 days? Skip the Finishing Pack and add K-meta which will need to be purchased separately (see next section).
Potassium metabisulfite (K-meta) is a preservative and anti-oxidant that kills/stunts unwanted microbial life and greatly extends a wine’s shelf life.
The kit will contain a Finishing Pack (see above) which includes K-meta. Note that this is the only K-meta in the kit, so extra must be purchased.
If you are bottling on kit schedule, the K-meta in the Finishing Pack is sufficient; no additional needs to be added.
If you are bulk aging longer, add 1/4 tsp K-meta at each racking (post-fermentation) and at bottling time, for each 19 to 23 liters of wine. K-meta binds to contaminants, rendering them harmless, and greatly extends the lifespan of the wine.
The contents of a wine kit are designed to produce a successful result every time. Follow the instructions and use good hygiene, and you will be successful.
A note on topping up: If bottled on kit schedule, there is no need to top the carboy. If good practices are followed, a 23 liter batch of wine will produce 27 to 28-1/2 bottles of wine.
However, if bulk aging longer, it is recommended to top up the carboy, e.g., filling with another liquid to within 2″ to 3″ of the stopper. I recommend using a similar or complementary wine. While there are other options, topping with wine avoids diluting your wine, and provides a guaranteed protection against oxidation.