Total Anthocyanins (tANT)
Figure 1. WINEXRAY's representative phenolic profile of a 21-day macerated Bordeaux varietal fermentation (The Future of Winemaking: Honoring the Vision of Professor Roger Boulton, 2022).
Total Anthocyanins (tANT) accounts for both free and bound anthocyanins in wine and is measured at pH 1.8 when the flavylium cation is fully pigmented. At wine pH (pH 3-4) the human eye can only see about 10-30% of the free anthocyanins, but bound anthocyanins notably more resistant to this effect.
From their peak extraction, Total Anthocyanins will decrease approximately 60-80% within the first 100 days post crush. This is in part due to their unstable nature in warm conditions that occur during this period (WINEXRAY). Overall, total anthocyanins measurement is fundamental for understanding cold soak efficiency, extraction efficiency, and the color potential of a vintage.
Anthocyanins are charged at wine pH and therefore water-soluble. Unlike tannins, they will partially extract in aqueous conditions (cold-soak) prior to fermentation, and completely extract in the presence of warm temperatures, movement, and alcohol. Cold soak is thus the only selective winemaking process that distinguishes between color and tannin. The efficiency of the cold soak can be determined as a percentage of peak total anthocyanin extraction during fermentation. This is a useful metric for monitoring adherence to protocols and understanding the characteristics of your fruit.
Cold-Soak Efficiency: <30% is low efficiency, 30-40% is moderate efficiency, 40-50% is high efficiency, and >50% is very high efficiency.
Peak total anthocyanins are a useful metric for evaluating the quality of the grapes relative to previous vintages. We continue to reference this value throughout the winemaking process. Within the first five to ten days of fermentation, if not sooner, peak total anthocyanin extraction is reached and rapidly begins to decline (WINEXRAY). Extending maceration decreases total color through an unknown mechanism, although notably not from reabsorption into grape skins (Casassa et al., 2013; Yokotsuka et al., 2000). The peak value is a fundamental metric for predicting the amount of bound anthocyanin formation relative to tannin extraction. We assume about 10% of total anthocyanins will naturally polymerize due to warm temperatures during primary fermentation. For example, a common practice in the industry is to extract 1.2x the concentration of protein-precipitable tannin compared to total anthocyanin. This tends to form a favorable bANT:pTAN ratio for Bordeaux-style wines. Whatever your methodology, the most important consideration is timing. The vast majority of bound anthocyanin polymerization occurs within the first 100 days post-crush when total anthocyanins are abundant. Winemakers can facilitate their formation by maintaining warm temperatures above 21°C (70°F) until they achieve their desired style.
It is important to acknowledge that warmer temperatures also accelerate the loss of free anthocyanins. If we only observe total anthocyanins during polymerization, then our instinct may be to cool the red wine down to cellar temperatures and prevent color degradation. As free anthocyanins are the majority of total anthocyanins in a freshly fermented wine, it is natural to see a rapid decline at warmer temperatures. Even at lower temperatures, these pigments degrade due to a variety of mechanisms (most notably oxidation). The key is to harness color potential while it is highly concentrated in musts and young wines. Below are reference levels for Peak Total Anthocyanin measured during fermentation.
- <500 ppm is a low amount of color found in high-production wines and/or low-color cultivars like Pinot Noir.
- 500-1,000 ppm is a moderate amount of color.
- 1,000-1,500 ppm is a high amount of color capable of producing a wide variety of wine styles.
- 1,500-2,000 ppm is very high color typically seen in highly pigmented cultivars.
- >2,000 ppm is extremely high color commonly seen in highly pigmented cultivars.
Winemakers can monitor the efficiency of extraction determined as a percentage of peak total anthocyanin/grape extractable anthocyanin (last) and by comparing the phenolic profiles of free run vs. press fraction. These are powerful metrics for monitoring adherence to protocols and understanding the characteristics of your fruit. It’s important to remember that all wine macerations are partial extractions. No fermentation ever extracts 100% of the phenolic material available. Peak total anthocyanin extraction tends to be <80% of berry extractable anthocyanins. This is precisely why winemakers should compare free run and press fraction total anthocyanin valyes to validate their extraction efficiency. A standard press fraction tends to have lower color and higher tannins than its free run counterpart. A low-efficiency extraction will have higher color and tannin in the press fraction than in the free run, and vice-versa for a high-efficiency extraction. All of these parameters together will fluctuate based on what actually happens in the fermentation, thus making them powerful metrics for winemakers.
Total Extraction Efficiency: <65% is low efficiency, 65-75% is moderate efficiency, 75-85% is high efficiency, and >85% is very high efficiency (WINEXRAY).
The most important takeaway for the total anthocyanin metric is simple, peak color is potential. Standard winemaking conditions will polymerize roughly 10% of the peak total anthocyanins extracted from the grapes during fermentation. Greater than 10% polymerization can be achieved by maintaining warm temperatures above 22°C (72°F) and delaying SO2 addition. It is one of the first indicators of phenolic balance during primary fermentation. How we take advantage of that potential in the first 100 days post-crush is critical for establishing wine style.
To learn more about Total Anthocyanins and their importance in winemaking, become a Bound advising client.
References
Colantuoni, G., McLeod, S. WINEXRAY LLC. https://www.winexray.com/
Casassa, L. F., Beaver, C. W., Mireles, M., Larsen, R. C., Hopfer, H., Heymann, H., & Harbertson, J. F. (2013). Influence of Fruit Maturity, Maceration Length, and Ethanol Amount on Chemical and Sensory Properties of Merlot Wines. American Journal of Enology and Viticulture, 64(4), 437–449. https://doi.org/10.5344/ajev.2013.13059
The Future of Winemaking: Honoring the vision of Professor Roger Boulton. (2022, November 7). https://livestream.com/accounts/11451219/rogerboulton
Yokotsuka, K., Sato, M., Ueno, N., & Singleton, V. L. (2000). Colour and Sensory Characteristics of Merlot Red Wines Caused by Prolonged Pomace Contact. Journal of Wine Research, 11(1), 7–18. https://doi.org/10.1080/713684213
Choose options
FAQs
Frequently Asked Questions
Supplies
- We supply 50 mL centrifuge tubes and labels upon request.
Sample
- Sample your wine in a way that is most representative of the entire lot (i.e. practice flushing your sample valve, collecting after movements like pumpovers, stirring your barrel, etc.).
Label
- Label each sample appropriately with your Client ID, Sample Date, and Sample ID. Samples for Phenolics analysis also require a Crush Date, Varietal, and Appellation. The analysis cannot be performed without the applicable information for each sample.
- Mark the sample type. ”Juice” applies to grapes and juice samples before fermentation. ”Must” applies to samples undergoing primary fermentation. ”Wine” applies to samples after fermentation.
- Select “Standard” for our corresponding juice, must, and wine panels, or select “Phenolics” for our phenolics panel. SO2 analysis can be included with the standard panel by selecting “with SO2”. Individual parameters can be added at the bottom of the label. A full list can be found on our ANALYSES page.
Clients are able to submit samples by scheduling a pickup, delivering directly to our lab, or via the mail.
To arrange for pickup, clients must be located near Lompoc, Buellton, Santa Ynez, Goleta, or Santa Barbara and notify us by 11 am for same-day retrieval. Established clients can also use our quick scheduling function by clicking the “LAB CLIENTS” tab on the bottom right hand corner of the screen. Be sure to select the correct date and provide all necessary details including instructions for pickup or requests for sampling supplies. Please contact us for more information.
- We provide same-day results by 7 pm with a guaranteed turnaround within 24 hours of sample receipt.
- Samples that are not analyzed same-daly are refrigerated overnight and analyzed first thing the next morning.
- Results are delivered via email in PDF format and uploaded to your account.
- Our invoices are sent via email and are due upon receipt.
- Your payment is securely processed through Bound’s website using one of the most trusted e-commerce platforms in the world.
- You can also opt-in to our invoice autopay feature by clicking “SIGN UP FOR AUTOPAY” on your account page.
To ensure their stability, we ask our clients either freeze or boil their juice / fermenting wine samples before shipment. Please note that boiling or freezing your samples may influence your results and we cannot guarantee their validity. Please contact Bound with any additional questions about sample preparation before shipment. We recommend expedited same-day to one-day shipping with a tracking number included.
Frozen
Samples can be placed in a freezer 24-hours in advance and shipped with an ice pack. Do not over-fill the polypropylene tubes or use glass containers as the frozen liquid will expand and could pose a safety concern. Freezing samples is a better alternative to boiling when analyzing compounds like ethanol, volatile acidity, free sulfur, and phenolics. Label each sample as "FROZEN".
Boiled
We generally do not recommend boiling your samples as it can significantly alter the chemistry of your sample. If necessary, samples can be boiled in their 50 mL polypropylene centrifuge tubes with a loosely fitted cap on top. Polypropylene tubes can be boiled up to 10 minutes, but be sure not to over boil as exposure to high temperatures can change your results. Label each sample as "BOILED".
Your data is completely private. Bound Lab and the services it provides are completely separate from Bound's commercial wine database.