What are they, and why do they appear in wines Crusoe Treasure?
The “wine diamonds” are small crystals sometimes found in the cork or at the bottom of wine bottles. Chemically, they are known as potassium bitartrate or calcium bitartrate, and result from the combination of tartaric acid, naturally present in grapes, with certain cations such as potassium or calcium. This phenomenon occurs especially in cold conditions or dynamic environments, such as those experienced during underwater wine ageing, a technique the winery Crusoe Treasure has perfected by submerging its bottles in the sea.
The appearance of these crystals is not a defect, but rather a sign of authenticity and an indication that the wine has been made with minimal chemical intervention. Their presence does not negatively affect the wine’s flavour, aroma or quality, which is why many people regard them as a fascinating natural curiosity.
Factors influencing the formation of wine diamonds
The likelihood of “wine diamonds” forming varies according to several factors:
- The tartaric acid content of the grapes.
- The level of potassium or calcium present in the wine.
- The temperature during fermentation, ageing and storage.
- The ageing technique, such as underwater ageing, where low temperatures and the movement of the sea encourage their formation.
How likely are diamonds to form depending on the grape variety?
Garnacha Tinta
Garnacha Tinta, known for its balance between acidity and sweetness, contains moderate levels of tartaric acid. This means that the likelihood of crystals forming in wines made from this variety is moderate. However, if Garnacha Tinta wine has been exposed to cold temperatures during ageing, as in underwater ageing, the likelihood increases significantly. This grape variety can produce wines with “diamonds” when bottled without treatments such as cold tartaric stabilisation, which removes these crystals.
Garnacha Blanca
Garnacha Blanca, like its red counterpart, has a medium tartaric acid content, but in this case the likelihood of crystals forming may be slightly higher than with Garnacha Tinta. This is because white wines are often kept cold for longer, whether during production or storage, creating favourable conditions for crystallisation. Garnacha white wines that have undergone underwater ageing are particularly prone to displaying these “diamonds”. As it is white wine, they are harder to see in the cork, but with a torch they become immediately visible when the cork is dry, as they are more difficult to observe when it is damp.
Tempranillo
Tempranillo, one of the most widely cultivated varieties in Spain, tends to have a high level of tartaric acid. This makes it particularly susceptible to the formation of bitartrate crystals, especially in young red wines or wines aged under natural conditions such as those of Crusoe Treasure. With its balanced tannins and high mineral concentration, Tempranillo is often a “friend” of wine diamonds.
Albariño
With its fresh character, high acidity and good concentration of tartaric acid, Albariño has a high likelihood of forming wine diamonds. This is particularly evident when the wines have not undergone cold stabilisation. During underwater ageing, Albariño can generate a notable amount of crystals due to the low temperatures experienced beneath the water.
Chardonnay
Known for its versatility, Chardonnay also contains high levels of tartaric acid, especially in cooler climates. This makes it a variety prone to generating bitartrate crystals, particularly when the wine is not filtered or cold-stabilised before bottling. However, in warm climates, where tartaric acid levels are lower, the likelihood decreases.
Cabernet Sauvignon
In the case of Cabernet Sauvignon, the tartaric acid content tends to be lower than in varieties such as Tempranillo or Albariño. As a result, “wine diamonds” are less common in this variety, although they may still appear in untreated wines aged in cold environments, such as during underwater ageing.
Verdejo
Wines made from Verdejo, with their bright acidity and high concentration of tartaric acid, have a relatively high likelihood of developing bitartrate crystals, especially if they have not previously been stabilised. This makes them ideal candidates for displaying the beauty of wine diamonds.
Underwater ageing and wine diamonds
The underwater ageing technique, employed by Crusoe Treasure, intensifies the formation of “wine diamonds”. Sea conditions, such as constant temperature, pressure and the movement of the waves, encourage this natural phenomenon in wines made using more traditional methods, avoiding all types of industrialised processes. This not only adds a unique visual element to the wine, but also highlights the purity and authenticity of its production process.
Ultimately, the formation of these crystals varies according to the grape variety and production techniques, but they are always perceived as a sign of quality and naturalness in the wine. So, if you find “wine diamonds” in a bottle of Crusoe Treasure, you are enjoying a unique experience and a genuinely crafted product.
Buy your bottle now and discover the wine diamonds in the cork.