Methoxypyrazines

What is it?

Methoxypyrazines are a group of compounds, found in both grapes and wine, which are responsible for the very characteristic ‘green, herbaceous, or vegetative’ aromas of Sauvignon Blanc, Cabernet Sauvignon and some other Bordeaux variety wines. Common descriptors include, grassy, bell pepper, herbal and leafy and these types of characters have been deemed to contribute to varietal character in these wines.

Why is it important?

Isobutyl-methoxypyrazine (IBMP) is considered to be the most important compound and is typically present in wines at concentrations of 5-30 ng/L. Isopropyl- methoxypyrazine (IPMP) and sec-butyl- methoxypyrazine (SBMP) are also present but typically at levels below that of IBMP and the limits of analytical sensitivity. All these compounds are considered to be very potent and have sensory thresholds in water of 1-2 ng/L.

Compound Typical levels in wine
(ng/L)
Aroma descriptors
Isobutyl-methoxypyrazine 5-30 Green capsicum, herbaceous, tomato leaf
Isopropyl-methoxypyrazine <10 Earthy, green bean, grassy, bell pepper
Sec-butyl-methoxypyrazine <10 Earthy

Various factors, including light exposure within the vine, vine vigour, ripening temperature and grape maturity, are all reported to impact on levels of methoxypyrazines in fruit. Grape maturity can dramatically influence the aroma intensity of these compounds in the wine and a small amount of grapes harvested early may be blended with those harvested later to increase the methoxypyrazine aroma intensity to a desired level.

Commercial Services analyses for all three methoxypyrazines (IBMP, IPMP and SBMP) in wine, juice and grapes, down to a concentration of 5 ng/L.

Price per analysis (excluding GST)
Analysis 1-7 8+
Methoxypyrazines $160 $145

For more information, please contact AWRI Commercial Services on (08) 8313 6600 or e-mail commercialservices@awri.com.au