Process

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Getting Ready for the Year’s Harvest

1997 planning assumption: given both increased production and our being less picky (or more picky, depending on how you view it), our wild guess is four times as much grapes as last year, so we will make sure we can handle five times as much grapes. Since we 7.5 had gallons of must in 1996, we will plan for 37.5 gallons in 1997.

Wrong!! …

To do every year:
 

Plan harvest party. Need more pruning shears (and more grape crates?).

Make sure we have fresh chemicals.

Review supply lists for what we need and identify who is responsible.

Reread steps in wine books.

Check batteries in all instruments.

To do:
 
Take three-day winemaking intensive course at UC Davis.
To get:
 
Demptos Cooperage – D
 
medium grain, medium toast Naverre 15 gal. and 7.5 gal oak barrels

silicon barrel bungs
 

Deciding When to Pick (Strategy)

Based on discussions with Brian, we decided that we would follow his practice and pick based solely on sugar content, adjusting acidity later as needed. In contrast, FVtW has both sugar and acidity desired ranges. Deciding based on sugar alone makes deciding when to pick simpler, but is a strong assumption about the well-formedness of the grapes.

Brian targets around 24° Brix. Divine targets 23.5° Brix. (In contrast, FVtW targets 22° Brix for all reds. MTWaH had no sugar target we could find.)

The Cabernets that we both like are complex and rich in fruit, acid, and tannin, that is, a reasonably big wine. To get such a wine, in 1996 we decided to pick in the range 23.5-24° Brix (or as close as we could get that let us pick on a weekend). This year we are targeting at least 24° Brix.
 

Measuring Sugar in the Grapes (Tactics)

We measure sugar every week or two until the grapes get to roughly 22° Brix and then we measure more often. The last measurement or two we sample more grapes.  

Dates	1996	1997
8/25/96 early evening	19°
9/2/96 early evening	20.4°
9/8/96 early evening	22°
9/10/96 8:30 a.m.	22°
9/14/96 morning	21.8°
9/18/96 8:00 a.m.	22.8°
9/21/96 6:00 p.m.	23.1°
9/26/96 a.m.	23.6°
9/28/96 6:00 p.m.  -- must measured	23°
8/31/97 5:00 p.m.		18.7°
9/15/97 8:30 a.m.		20.7°
9/21/97 6:00 p.m.		22.5°
9/26/97 8:30 a.m.		23.2°
10/3/97 8:30 a.m.		25.0°
10/4   -- must measured

 

The "curve" seems a bit arbitrary. Our best theory is that sugar increases more with something like degree-hours than with days, but that this slows down toward the end as the grapes get bigger. A very hot day increases the sugar much more, especially late in the maturing. 1996 had some very hot days in the second half of September. To examine the effect of temperature, we would capture the maximum temperature for each day. (Does Foothill College’s radio station log this?)
 

Pick Day

Prep:
 
Walk through all the steps.

Mark any new primary fermentation containers every two gallons.

Make fresh citric acid and bleach solutions.

Clean well grape picking boxes, crusher, fermentation containers, and puncher.
 

Note: As with many things, the time is in the prep work, especially the cleaning, not in the picking itself.
Make potassium metabisulfite solution. This year we will add 40 ppm at pick.
 
.08 g./gallon x 40 ppm/10 ppm x 37.5 gallons = 12 g.

.32g/gallon

Mop the floor.
Pick grapes, removing most of the bad grapes as you go.
 
We were brutal in ’96, throwing away anything but the most perfect. We will include more bunches in 1997.
Destem and crush grapes into primary fermentation container, filling no more than ¾ full to allow for frothing. Filling ¾ full rather than 2/3 full requires punching down more often during active fermentation to release the energy (twice a day seems to work).

Record Brix with both refractometer and hydrometer (MTWaH, p. 28).
 

pH.

Temperature.

TA.

Taste must.

and add to the must.

Make plastic tarp for PFC, cover PFC, and use clip to tighten string to make fairly airtight.

Calculate and record available alcohol^TK.

Record all measurements and additions to the wine.

Wait 6 hours to let SO₂ settle into the must, killing the bad bacteria.

Punch down must.

Add yeast and yeast food to the must, stir, and re-cover fermenter.

Measure temperature.
 
 

Each Day between Pick and Press

1. A quiescent period of 12 to 24 hours, during which yeast cells grow and increase.
2. Vigorous activity of 2 to 3 days, during which the yeast rapidly ferments two thirds of the sugar to alcohol and carbon dioxide. The CO₂ causes frothing. The skins rise to the top, become compact, and form a cap.
3. Relatively slow fermentation for 3 to 4 days.

Measure and record Brix, temperature, TA, pH, and time.

Measure sugar with:

Pressing

MTWaH says press the must after 2/3 of the sugar is fermented. Is that Brian’s practice?

Prep:
 

Attach press to pallet.

Clean press well. (WBWCW)

Clean tubing, containers well (WBWCW)

Calibrate pH meter.

Go over steps for pressing.

Concern with the press we have: it breaks the seeds, imparting some bitterness to the wine.
 

Fermentation

Prep:
 
Go though steps of measuring TA, Brix with hydrometer, and weight.

Figure out how to adjust TA.

Oak

Store barrels filled with water with 100 ppm SO2. This will cost some of the oak on the water, but will prevent barrel from problems such as volatile acidity.

Brian stores in neutral oak. We are very conservative about possibly inheriting someone else’s problems.
 

Throughout

Send samples of the wine to Michael Murtaugh at The Wine Lab every four months to be tested.
 

Bottling