pH, TA, and Malolactic info

Red wine pH should be between 3.4 and 3.6. TA should be around 7 g/L. Malolactic Fermentation (which converts malic acid into lactic and makes red wines smoother and more awesome) has the following effects on acidity (according to this site:

* a pH increase of between 0.1 and 0.45 units (more typically 0.1-0.25)
* a chemical deacidification usually reducing titratable acidity by about 1-4.6 g/l (as tartaric)

So, our wine currently has the following stats:

pH 3.5
TA 8.5 g/L

After ML, it could potentially have the following stats:

pH 3.6 – 3.75
TA 3.9 – 7.5

I’m not ok with the risk of the pH being over 3.6, which makes me think I should adjust pH to 3.4. However, I’m also not ok with a TA over 7, which makes me think I shouldn’t adjust.

After some more reading, it sounds like what we’ve got is a higher concentration of Malic (a weaker acid) than of Tartaric (a stronger acid). This explains why the pH (which measures the effect or strength of the acid in the wine) is high (less acid strength) and the TA is high (more acid).

So, if I adjust with Tartaric acid, I think it will decrease the pH and increase the TA, but the Malolactic fermentation will have a larger effect because we have a relatively high concentration of Malic.

If you’re a chemist, please let me know if I’m on the right track here!

If you’re not familiar with TA and pH, here’s some reading.


We picked up our Zinfandel grapes from Fair Play Farms in El Dorado County this morning. Fair Play Farms is where Perry Creek gets their grapes for their premium high altitude (2401) wines. They taste great, and the numbers are pretty much right where I want them to be. A crowd of people showed up at the winery to help crush them, and we had it knocked out in just a couple hours. Thanks everyone! Once everything was crushed and the equipment cleaned up, I pulled off 6 gallons of juice to make into a Zin Rosé.

The sugar fluctuated from between 23 and 25 brix. I’ll take another reading tomorrow before adding yeast and see if it’s settled on something.

pH was at 3.5. This is maybe slightly less acid than I want. However, TA was .85%, which indicates slightly more acid than I want…so what do I do? My current thinking is to do some research tonight and test again tomorrow before making any adjustments at all.

Come have some fun and drink some wine!

The Bad Astronauts Winery, in cooperation with the Sacramento Institute of Fun (of which I’m a co-founder) will be holding a wine appreciation class this Friday evening at Revolution Wines. Teaching the class will be Corti Bros’ Wine Merchant Donal Smith. The fee for this fun and wine-tacular event is just $40. Contact me for more information.

This is the first public Bad Astronauts event, and we’re limiting participation to around 30 people. We still have about 8 spots left, so if you’re interested or if you have questions, give me a holler!

Merlot Update

Here’s the latest from our Merlot vineyard:

It’s been a strange week weather-wise. After triple digit temps last week we now have cold, damp fog that lingers. Brix is at 23 plus or minus and I’m guessing harvest in about two weeks.

Barbera – the story

Sam and I drove to Drytown Cellars (near plymouth, in Amador county) today to pick up the club project red wine (Barbera). We got there at about 12:20, and there was mass confusion. We somehow got our 250 lbs into the truck, paid, and got out of there…I’m still not real sure what was going on. We added 50 ppm SO2 before leaving.

When we measured the sugar at the winery, it was 26 Brix. We stopped at American Ice Company on Del Paso on the way back and bought 30 lbs of dry ice. We through 10 lbs into the macrobin. We left the other 20 lbs (2 10lb blocks) in the cooler and drove back to the winery.

I should have taken a picture of the dry ice in the must. It looked very cool with all the smoking. We bailed the smoking must and dry ice into a primary fermenter and wheeled it back to the winery.

The temperature of the must was about 75 degrees when we got back (around 2:30), and it dropped to about 65 degrees by 4:00.

I tested the must and got these numbers:

26.8 Brix
.7 TA (not real sure about this)
pH 3.31

We stirred it up a little and then put a lid on it. The goal with this must is to keep it cold and prevent fermentation for 24-48 hours in order to extract more color from the skins.

UPDATE: We took some of the must to Revolution Wines and had them test with their (far superior) equipment. Here are they numbers they got:

pH 3.23
TA 1.095

Chenin Blanc – the story to date

We picked the Chenin Blank in Clarksburg yesterday. Here’s how it all went down.

We drove down there with Maya and Sam’s gang. The son of the vineyard owner (Steve) showed us where the vines were that we could pick. The field had been mechanically picked the morning before, and we were allowed to come in and pick the ends of the rows for free. The grapes were right next to Bogle’s Chardonnay vines.

We took a field test of a few grapes and decided the sugar was at 23 brix. We got to work at about 10ish, and we had picked somewhere around 750-900 lbs by noon.

When we got back to the winery, we set up the crusher/destemmer and the press next to each other and set up a production line. One person (me) stood in the truck and bailed out grapes. The next person (Kathy) brought the grapes back to the crusher. The rest of the folks took turns crushing, dumping into the press, pressing, and dumping into the primary fermenter.

When we were done, we had about 56 gallons of must. I ran some tests and got the following results:

22 Brix
TA .95%
pH 3.31

I took 6 gallons and Ian took 5 gallons. Sam and Jim split the rest between 2 primary fermenters.

I added about 75ppm SO2 to my carboy and then put it on ice in the winery at 3:00. At 3:30, the temperature of the must was 75 degrees. At 7:00 it was 56 degrees.

This morning (8:00), the Chenin Blanc was at 60 degrees and I added more ice to the tub it’s in. At 5:00, it was 64 degrees.

At 7:00, I pulled the carboy out of the tub and saw that there was about 2 inches of sediment on the bottom. I decided to rack it.

I added 3tsp pectic enzyme and 5.3 grams Fermaid K to a smaller carboy (5 gallons) and racked.

Then, I rehydrated the yeast (EC1118) and added it.

UPDATE: here are the numbers we got when Revolution tested it with their equipment:

pH 3.28
TA .84