The alternative to the punchdown technique I discussed last week is what we call the pumpover. If the cap is too thick to punchdown by hand or the winemaker thinks that the fermenting wine needs to be more thoroughly mixed, we use this method. We have a large hydraulic “foot” that attaches to our forklift that we can use to punchdown the large stainless steel tanks but for the most part we perform pumpovers on the tanks.

A cylindrical stainless steel strainer is inserted through the cap at the top of the container. This can be really difficult sometimes if the skins are too compacted. As soon as the strainer breaks through, the juice comes bubbling up to the top. Then one end of a hose is inserted into the strainer, which is long enough so that the hose can reach the liquid well below the cap. Using one of our powerful compressed air pumps we pump the juice over the top of the cap evenly for about 15 minutes – hence the name. This way the skins stay wet and the must at the bottom of the vat is able to come in contact with the skins. This adds enough oxygen to the must for the yeast to survive, stay happy, and do their job. Occasionally the juice gets sucked out of one area and the strainer needs to be moved around.

Pumpovers are much easier to do than punchdowns. The downside is that the pump must be cleaned between each pumpover. The foot that is used for punchdowns is easy to rinse and spray down with alcohol. But the pump must be taken apart, the remaining wine drained out of the machine and the hoses, then added back to the tank (only about half gallon, but it adds up after several weeks). Then the pump is reassembled and a proxy solution is circulated through it, then a citric acid solution and finally water. Once again it must be taken apart, and the hoses drained. Finally it is reassembled for use on the next tank. After doing this about a hundred times you get very fast at it but it still can take longer to clean the pump than it does to actually use it!

Personally I like doing pumpovers better than doing punchdowns just because the risk of falling in the bin and ruining the wine is stressful. So far we’ve covered sorting the fruit and one aspect of the primary fermentation process. The journey continues next week on DeerfieldCellarRat.com!



When I moved into my tent at the winery over a year ago I wondered why in the early morning I would hear what sounded like a fleet of helicopters landing in the vineyard. I now know that what I was hearing was the sound of vineyard owners battling the frost that threatened to destroy their grapes. If the temperature drops to below 32º F for more than 30 minutes there is a chance that ice crystals will form within the plants cells and destroy any green growth. During the spring when the buds are forming that will produce the fruit for harvest, the entire crop is vulnerable. In the fall early rains mixed with low temperatures can cause the grapes to shatter on the vine. Growers have developed a number of ways to combat this potentially disastrous scenario. Overhead sprinklers are one such technique. By covering the vines in water constantly the plant tissue will remain at 32º as long as the temperature is above 20º. The technique is effective but the systems are expensive, require maintenance and use about 55 gallons per acre per minute to be completely effective. That’s a lot of water. Heaters have also been used, though usually in conjunction with another method. Vineyard heaters for commercial use must comply with California emission standards but still can burn up to about a gallon of diesel fuel an hour per unit. Imagining the vast vineyards of California blanketed by these heaters makes the environmentalist in me cringe. The fans I mentioned earlier circulate the warmer air that is higher in the atmosphere. These can raise the temperature at the level of the grapes to 1/4^th the difference between the temperature at 4 feet off the ground and 40 feet. So if there is a 4º temperature difference the fans will effectively raise the temperature at the height of the vines by 1º. The Department Of Agriculture’s Natural Resource Conservation Service is working with vineyards owners to switch to this method to conserve water. Maintaining soil that radiates heat effectively is an important component that can be utilized to bolster any frost protection strategy. Soil that is clean, firm and moist is best. Research recently done at the University of California, Berkeley indicates that the ice crystals that form in plant tissue must have a nucleus on which to form. Bacteria is what provides such a nucleus so by reducing the amount of ambient bacteria present on the vines the risk of frost should theoretically be reduced, though this strategy has yet to be implemented commercially. Frost damage is not a threat everywhere in California but in the Valley of the Moon where Deerfield Ranch Winery is located it is a threat that we contend with every year. We made it through spring without too much issue, though we did use our dual purpose irrigation system which makes use of water that is recycled by our on-site water treatment bioreactor. Usually, in Sonoma county, fall frosts which damage crops are rare because typically the fruit has been harvested. We can't seem to catch a break this year: A frost warning was issued for Wednesday morning. It looks like this time that the threat didn't materialize though. Deerfield is planning to pick its entire Syrah vineyard by mid next week. I'll let you know how it goes!