Showing posts with label lactic acid. Show all posts
Showing posts with label lactic acid. Show all posts

Sunday, October 23, 2016

First Crush

It was a breathtaking drive from Seattle to Snoqualmie that sun-soaked September afternoon. I was exhausted and a bit cranky, having to juggle work and taking care of a sick husband and an injured dog.

However, mother nature had chosen the harvest date, and then we were given but a few days notice to get ready for the crush. I left my invalid family members in the good hands of our house guest, packed the primary fermenter, towels, and rubber boots into the Forester, and headed out to the crush facility. My excitement grew as I approached the facility - my first crush!

Crush Day

Our Syrah grapes were picked earlier that day from Chandler Reach Vineyards, technically considered to be in the Yakima Valley, but within close proximity of the Red Mountain AVA. My partner-in-wine, Alisa, and I decided to share 100 lbs of grapes between us, which would make us about two cases of wine.

At the crush facility, the winemaking class instructor, Steve, showed us how to set up the crusher and de-stemmer. All equipment were rinsed appropriately before we proceeded. Working in a group, we gently dropped bunches of grapes into the machine, which quite efficiently removed the stems and lightly crushed the grapes into the primary fermenter. But just in case, there were two of us who manually picked out stems that were missed by the machine.

There was a certain rhythm to crushing grapes that relaxed me. It was almost therapeutic! This was the first crush for most of us, and we were eager to learn and to help. As we got the hang of it, we moved faster through the bins of grapes. Our sticky grape stains were evidence of our achievement that day.

Gently dropping grapes in
Crushed and de-stemmed

More stems manually removed
Must in primary fermenter
The freshly crushed grapes, also known as must, smelled terrific. Sulfite was added to remove any wild yeast and bacteria from the must. After crushing nearly a ton of grapes (literally) and cleaning up all the equipment, it was time to take some measurements before we took the must home.
  • Brix, which measures the sugar content of the must, was at 26 degrees. It was higher than the desired range of 22-25. A higher than desired Brix might lead to high alcohol content before fermentation could complete. This could result in a stuck fermentation.
  • pH, which measures acidity, was at 3.53 and was within the desired range of 3.5 and 3.8.
  • Titratable acidity (TA), which measures the amount of all the combined acids in the must, was at 7.125g/L and was slightly higher than the desired 4-6g/L.
The adjustment to the must needed was thankfully simple enough. To correct the Brix without adversely impacting the pH and TA, we diluted the must with water with precise measurements that Steve provided.


Alisa, my partner-in-wine, and I with our must
Primary Fermentation

A full day after the crush, we introduced re-hydrated yeast into the must and proceeded with the twice to thrice-daily punch downs. Punching down is a process to keep the juice and the crushed grapes, particularly the skins, in contact during primary fermentation. As must ferments, the crushed grapes tend to rise to the top forming what is known as the cap. Pushing the cap down into the juice allows for flavor extraction and also prevents unwanted bacterial activities.

A pack of nutrients were added to the must two days later to feed the yeast, and a second pack was added after another two days. The must was bubbling happily and got hot (around 75 to 80 deg F) with yeast activities. Unfortunately, I never got to the desired temperature range of 80 to 90 deg F. But the house smelled like a winery during primary fermentation so I took that as a good sign!

Yeast hydrated in must and warm water

Must bubbling during fermentation
In less than a week after the crush, the Brix had dropped to 6 degrees. Twice-daily punch downs continued, and four days later, the Brix measured at -1 degree. The must was then inoculated with malolactic (ML) bacteria as we prepared for the press the next day. The ML fermentation process allowed for a controlled conversion of the tart-tasting malic acids to softer lactic acids, which would hopefully enhance the body and flavor of the wine.

Press Day

To prepare for the press, all equipment needed to be sanitized. It was not the most interesting part of winemaking but very necessary to ensure that no wild strains of yeast or bacteria would enter the juice. ML bacteria was added a day before the press so that it could benefit from being evenly distributed in the juice during the pressing process.

Sanitizing 
There were three batches of must at Steve's house that day, ready to be pressed. Steve pulled out his beautiful press from the turn of the 20th century. It belonged to his grandfather and was quite the treat!

Our must had been in primary fermentation for about ten days at that time. We poured the must into the wine press and let the juice flow into a container at the bottom of the press. This is what is known as the free run. Following that, we placed heavy blocks of wood onto the crushed grapes and exerted pressure to press the remaining juice out. The unfinished wine went into the sanitized carboys and gallon jugs, that were then air-locked.

Beautiful wine press and free run
Pouring pressed wine into carboy

The day ended with a quick sampling of the three different juices. Within only ten days, you could already taste the difference among them. Some of us (not me) had clearly done a better job with punch downs and keeping the temperature at the higher and more desired range. Those juices showed a bit more tannins and structure. My juice, which was fermented cooler and with less intervention, was more fruit-forward. I can't wait to see how our wines will continue to evolve.

My Verdict: I was a skeptic when it came to winemaking. Given the abundance of great wines available, there is hardly any need to make my own wine. However, I've been having great fun so far. I've also learned a lot about what goes on in a wine. Stay tuned for my post on secondary fermentation and bulk aging.