Lab Work Part 2

I also check if the wines are protein or heat stable and if they are cold stable. If the wine is not protein stable there is a chance that if the wine got warm during shipping or storage for instance that it would throw a protein based sediment. This doesn’t affect the flavor nor is it a health issue but it’s not at all attractive. When it is bad it looks like strings of slime floating in the wine, otherwise it just makes a cloudy mass at the bottom of the bottle. I check the wine by filtering it clear using a syringe filter, great for filtering small quantites, and then heating it for 6 hours in my homemade water bath. Below are two samples, one passed and one failed. If a wine fails I run lab trials treating the wine with different levels of Bentonite and retest, when the wine stays clear I know how much I need to add to the tank.
Cold stability on the other hand is an issue if the wine sits in a cold fridge for a long time or is put in the freezer and forgotten about. I’m sure that’s never happened to any of you. When the wine is not cold stable it will throw crystals in the bottle that normally form first on the cork and are about the color of the wine. Again nothing to worry about, it is just cream of tartar, like used in cooking, but in crystal form. They are not pieces of glass which it can resemble if it falls in the bottom of your wine glass. To check the stability of the wine I first centrifuge a sample of the wine to help save my lab filter, and then filter it to get it completely. Finally I freeze the wine and see what crystals form at the bottom. If too many form then I chill the tank of wine until all the crystals form in the tank and then filter the wine. I like to do this step last so that I only filter the wines once. As I could talk to several hours about my thoughts of filtering and wine I’ll save that for another day. I do think that it is a great tool and has its place in the winery.
Just for laughs: This is what happens to wine bags at our house. Meet our evening entertainment; Ferb is in the bag and about to be attacked by his brother, Phineas.