stable haze can also be created with over-use of a proteinaceous fining agent.


There are several proteinaceous fining agents in use and each has a slightly different influence on wine. The most common is gelatin, used mostly to tie up tannin during white wine production. It is also used occasionally to remove astringency or bitterness in red wines, but is not as effective as some other agents. The effectiveness of gelatin varies as its molecular weight. Low molecular weight gelatin is more effective at removing tannin, yellow tint, and bitterness in white wines. Isinglass is widely used in the beer industry, but some winemakers prefer it to gelatin, because it is more consistent in composition and activity. Isinglass is more


controllable when trying to fine-tune a treatment.


Other proteinaceous fining agents are potassium caseinate (from milk) and PVPP. Potassium caseinate is very effective at removing colour, especially in wines that have acquired excessive browning. PVPP is another agent widely used in the brewing industry and occasionally in wines for the removal of bitterness. Needless to say, don’t ever trust that just because you found the effective level during your bench tests, that the treated tank will be completely stable. There are lots of things that can go wrong between the bench and the tank.


If your bench test indicates that you require a heavy treatment of, say, 600 mg/L, you can be more confident of the effectiveness of the treatment by treating with two smaller doses and testing in between. You may require less for the second treatment. It’s a good idea to maintain the mind set that less is better. Even after having treated with the level that you think is correct, always test it again before bottling. There are other ways to fine, of course. There are cellulose derivatives, colloidal silicon dioxide, yeast hulls, egg whites, activated carbon, and various combinations of many of these. There are some methods that are no longer used and many that haven’t been tried yet. With modern winemaking methods I foresee that the practice of fining will decline. Partly, this is because it will eventually be displaced by cross-flow


filtration and partly because we are learning more about maturity assessment.


When you add tight quality control in winemaking to optimal berry


maturity, the resulting wine requires little, if any fining. That’s fine with me.


—Gary Strachan can be reached at gestrachan@alum.mit.edu .


Proud Distributors of Rack & Maintenance Source All Rack & Maintenance Source racks are made to handle Burgundy, Bordeaux and American Barrel shapes. All standard order racks have four crossbars to maximize strength and safety. The one exception to this is our two barrel half-rack or bottom rack.


GERARD’S EQUIPMENT LTD. 33684 Highway 97 South, Oliver, BC


(250) 498-2524 or (250) 498-6231 • Fax (250) 498-3288


CERTIFIED Lab Testing Above


State Requirements Top Notch Service...


Classic wines…and superior vines…don’tgrow overnight. They must be nurtured slowly and meticulously. It starts from the very beginning with Vintage Nurseries. Our seasoned professionals notonly create the perfect growing conditions, but eagerly dispense expert advice and tend to every detail. Whether in our nursery or your vineyard, we answer all of your questions and offer suggestions, so that you can feel confident with the selections you’ve made. At Vintage Nurseries those selections are, like our service, a cut above. The result? Vintage quality, year after year.


Wasco 661-758-4777


Paso Robles 805-237-8914


Modesto 209-523-8036


Santa Rosa 707-542-5510


800-499-9019 www.VintageNurseries.com


Serving the Wine, Table Grape and Raisin Industries British Columbia FRUIT GROWER • Spring 2011 33


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40