There is a chemical compound that can sometimes develop in wine called 2-acetyltetrahydropyridine, or ACTPY for short. The aroma is described as being like “caged mice and cracker biscuits”, and believe it or not, it is actually very difficult to smell (simply because it is a basic compound). It is much more likely that you will detect it on your palate as it’s release will be triggered by your own pH. Wine is obviously acidic and it is only when you put the wine in your mouth that the pH increases and the compound returns to its aromatic form, allowing it to be tasted.

Owing to the time it takes for this reaction to take place the evolution of the mousey flavour can be delayed…it might take about 30 seconds or so to develop on your palate. If you taste it in a line up of several wines it is important to identify the right wine as the culprit, and make sure that this off flavour isn’t carried over from a previous wine! The sensation can also persist in your mouth for several minutes and therefore it can be difficult to taste other wines afterwards.

There are two main origins of this off-flavour– microbial and chemical. If it’s microbial, it comes from strains of lactic acid bacteria or yeast, and if its origin is chemical, it is associated with the process of hyperoxidation (when hydrogen peroxide is used to remove SO2 from juice or wine). Thankfully, the latter is not a process that we use at Castro Martin. At this time there are no methods for measuring the level of mousiness in wines, and detection is still reliant on tasters, sensitive to this off-flavour. The other bad news is  that there’s also no verified ways to remove the character, other than blending away the affected wine.

As with any microbial and chemical fault in wine, prevention is always better than cure!

There is a chemical compound that can sometimes develop in wine called 2-acetyltetrahydropyridine, or ACTPY for short. The aroma is described as being like “caged mice and cracker biscuits”, and believe it or not, it is actually very difficult to smell (simply because it is a basic compound). It is much more likely that you will detect it on your palate as it’s release will be triggered by your own pH. Wine is obviously acidic and it is only when you put the wine in your mouth that the pH increases and the compound returns to its aromatic form, allowing it to be tasted.

Owing to the time it takes for this reaction to take place the evolution of the mousey flavour can be delayed…it might take about 30 seconds or so to develop on your palate. If you taste it in a line up of several wines it is important to identify the right wine as the culprit, and make sure that this off flavour isn’t carried over from a previous wine! The sensation can also persist in your mouth for several minutes and therefore it can be difficult to taste other wines afterwards.

There are two main origins of this off-flavour– microbial and chemical. If it’s microbial, it comes from strains of lactic acid bacteria or yeast, and if its origin is chemical, it is associated with the process of hyperoxidation (when hydrogen peroxide is used to remove SO2 from juice or wine). Thankfully, the latter is not a process that we use at Castro Martin. At this time there are no methods for measuring the level of mousiness in wines, and detection is still reliant on tasters, sensitive to this off-flavour. The other bad news is  that there’s also no verified ways to remove the character, other than blending away the affected wine.

As with any microbial and chemical fault in wine, prevention is always better than cure!