Winemaking Explained

I just wanted to add some information about managing your winery’s microbes as presented by ETS Laboratories. This is information from a seminar I went to in April 2015.

As most of us who have been doing this for a while know, the conversion of grape juice to wine is a biological process involving both yeast and bacteria.

Wine spoilage can be caused by more than one organism. Spoilage can be wither overt, covert or both. Overt spoilage can occur over a wide range of concentrations. Covert spoilage can occur at lower concentrations of the same spoilage compounds.

This is a link to one of my favorite podcasts. Jim Duane is the winemaker for Seavey Vineyards in the Napa Valley.

I highly recommend this to anyone who enjoys listening to podcasts.

So, harvest is here! Today I was working with water and acid adds. I was given a formula to work with and I thought I would share it. It will also help me to type this out and be able to reference when I need to.

I can’t remember exactly why it’s done this way, but I think it’s something with changing the water pH and still having the proper amount of acid. I will ask tomorrow and update this, or write a new one.

The point of an acid and water addition is to bring the Brix down for a lower alcohol wine, and to adjust the pH and total acid so the finished product has a balance of alcohol, acid, and flavour. These adjustments are always made on a personal preference and stylistic choice.

For this example I will be using a tank with 2,400 gallons (2,400gal) of white juice post racking with a Total Acid (TA) of 5.5. The rate of tartaric acid (HTA) I want to add will be one and a quarter gram per litre (1.25 g/L) and the percent of water (%H2O) I want to add is 5%.

The math is as follows:

2,400 x .05 = 120

120 x 3.785 x 5.5 / 1,000 = 2.4981

120 + 2,400 x 3.785 x 1.25 / 1,000 = 11.475

2.4981 + 11.475 = 13.9731

And here is the breakdown:

• 2,400gal juice x .05 (5%H2O) = 120gal H2O

• Water and TA: 120gal H2O x 3.785 (conversion of gallons to litres) x 5.5 (TA of juice) / 1,000 (easier for me to know the decimal movement) = 2.4981

• Total volume and g/L tartaric: 120gal H2O + 2,400gal Juice x 3.785 (conversion of gallons to litres) x 1.25g/L 

HTA / 1,000 (easier for me to know kilograms) = 11.475kg

• Water and TA + Total volume and g/L tartaric acid: 2.4981 + 11.475 = 13.9731kg HTA.

As it turns out, I’m drunk now off of Jameson Irish whiskey and Czech and Russian beer. So I will have to conclude this another time. However I’m pretty confidant that all the math I did was correct and I would love to hear any input from people. I will do another post and do a better job on explaining how this works.

I know I may write things a bit too simplistic, but as I have said before, this is a blog for people who don’t have any proper education in chemistry, biology, microbiology, organic chemistry, math or wine making.