Ξ October 29th, 2008 | → 2 Comments | ∇ A Day at a Time, Interviews, Technology, Wine News |
In part 2 Andrew Yap, Director of Oenology and Industry Marketing at Cavitus, passes through a modest series of more technical and commercial matters. Especially interesting is Mr. Yap’s discussion of the potential use of ultrasonics to purge TCA from corks and to increase the extraction of color and flavor from certain grape varieties grown in challenging warm-climates.
Part 3 will focus on the nuts and bolts of the HPU unit itself. Mr. Yap will walk us through each step of the sonication process.
Admin Could you say a few words about Darren Bates?
Andrew Yap Sometime after 2002 I came upon Darren Bates who is our Director of Technology and CTO [Chief Technical Officer]. He is the world-wide expert on ultrasonics. In fact, if your winemaker friend wants to know more about ultrasonics he should contact him, as may any winemaker. He is knowledgeable about all aspects of ultrasonics, whereas I am an oenologist applying the technology to barrel cleaning, to color and flavor extraction, defoaming, fermentation management, and a range of applications in the wine industry.
Your experimental trials used 225L barrels. Can you tell us something of the water use required, and is this technology scalable, can it be used to clean larger barrels?
AY It is scalable. The Beta Prototype that we have designed is contained within an eight foot by ten foot container for a very good reason: we have to move it from winery to winery and from country to country. So, all the components of the system are within this [container]. Now, if you already have got a system in place and you don’t really want this container, you want some of the components because you already have your hot water system, you’ve got your filtration system, you can utilize all these and retrofit the ultrasonic equipment into your system. And this is what many of the big wineries plan to do.
But if you don’t have a cleaning system, or have one of those mobile, hand-held high pressure hot water cleaning systems, then our system might be the one you want to employ. The other advantage of this system is that you can drag it around from winery to winery and provide a mobile service to small wineries.
Do you plan a rental service?
AY We’re looking to appoint service providers here. We haven’t come to any arrangements yet. The service provider may not be the distributor but some organization which is already doing this sort of mobile service, like bottling, dealcing, whoever they are. We plan to have such services in the different states. In fact, during the Unified Symposium in February this year there were people from Washington state, from New York state and other places interested in using this facility but yet too small to justify buying big equipment like this. So, one way to use this application is to get a mobile provider to come around to your winery on a Sunday and clean x number of barrels for a fee, just like what is now being charged for cleaning services provided by other people.
Now, coming back to the barrels, the barrel size for this unit is for 225L and 228L, those are barriques in the Burgundy style and Bordeaux style. One is longer and slightly larger than the other. So this unit will accommodate those two. Once you take away these outer parts [pointing to the front face of the unit] then you can use it for any barrel size up to hogsheads and puncheons.
Is the toasting level of the barrel an issue when you apply high power ultrasonics?
AY No, no, that shouldn’t affect it. Now, if your barrel is very heavily tartrated, of course you’ll remove the tartrates and expose the sub-surface layers to the ultrasound, the ultrasound to the brett to remove any residues in the pores and from the grain.
Has there been any analysis of the effect of HPU on the oak flavor?
AY We exacted the wash water after sonication and we couldn’t detect that any oak flavor compounds had been removed. That is a very positive thing. Now, having said that, we presently have a trial at a winery in the Barrosa Valley where they’ve cleaned barrels of different ages with high powered sound and at the same time cleaned them with high pressure hot water. As a base line we used clean and new barrels, so we have a big range. Then we put wine into these barrels and we’re looking at the extraction of the oak flavor compounds over twelve months. So, it’s very early yet, we started in August, I think, so only about three months worth of data. Whereas with the new barrels we could see a very rapid extraction of oak flavor compounds, with the barrels cleaned by high pressure hot water and high powered sound, there is extraction though not at the rate of a new barrel, of course. But what we are mainly interested in is whether with HPU, the sonicated barrels, we get more oak flavor extraction, faster extraction.
Now, if it’s faster extraction then instead of putting your wine in a barrel for 8 months or 12 months, as winemakers do, within 6 months you might be able to get the flavor compounds that you need for the wine. Now you’ve saved time. You can get your wines earlier to the market if you like. Even with two, three, or four year barrels you put your wines in you’ve got the style that you want earlier, so that’s a savings to the winery.
Of course, it’s important to point out that apart from brett/dekkera, HPU is effective on all spoilage bacteria and yeasts, at least according to your research.
AY Yes, that’s right. I should mention that all out trials have been on yeasts, although we’ve looked at the wine yeasts, Saccharomyces cerevisiae and one other yeast, so HPU has been effective against these three yeasts. But now the University of Adelaide people are looking at the efficacy of ultrasonics on all the other types of spoilage and wild yeasts, lactic acid bacteria, acetic acid bacteria, all the spoilage ones you find in barrels.
Have you taken an interest in TCA?
AY We came up with this idea when we first started. We told ourselves, “How can we make lots of money very quickly!” (laughs) TCA contamination is a huge problem with corks, now maybe we can suck all the TCA compounds out of the cork and then release the sonicated corks to the market. That’s still at the back of our mind. We haven’t gone down that track yet. But it’s a possibility.
The way in which ultrasound works, wherever there are pores, like you would find in corks, if you can get the water in there and with the acoustic streaming, the mass transfer, it’s possible that whatever is in the pores will be sucked out as well. That’s the theory, right? But you need to prove it. I mean, we’ve proved it in barrels, HPU does go through the pores, up to 14mm, which is way beyond what wine travels. If you can do that anything that’s in there gets sucked out, anything embedded in it, the barrel, will get killed.
Now, about water usage, hot water cleaning treatments require a constant stream of hot water. Does your system simply require that the barrel be filled? And is that water then recycled?
AY Firstly, in terms of water, what is required is reverse osmosis water, it’s easy to produce; most wineries have an RO system. In fact, when we take this around we actually take a RO system with us. Because water quality differs so much from region to region, winery to winery, and water quality affects the effectivity of ultrasound, so, if you use RO water that is degassed we can easily clean a one year-old barrel, that has just been used once, within five minutes. It will be back to its normal surface.
If you use water that hasn’t been degassed and has high solids, it may take six or seven minutes. That’s a difference.
[A more complete answer to this question will be given in part 3.]
You earlier mentioned using this technology also for the extraction of color and flavor.
AY Let me first say that the wine industry side is a small side for our company. Our big business is in food processing. We have arrangements with a dozen of the big food companies, Fortune 500 companies, using ultrasound for a range of processes. So the wine side is pretty small when you compare it to the food industry. For example, in the food industry we can treat food products at 100,000 gallons per minute. We have been doing trial here in California looking at extracting more color from the must at around 50 gallons per minute. Now, some wineries, most wineries, run their pumps at 100,000 to 200,000 gallons per minute. That’s already been done in the food industry. We’d have to up-scale if we want to use this process in the wine industry.
But what you apply in the food industry for a particular product, whether to change the viscosity, to pasteurize it, does not necessarily apply to the wine industry for affecting color and flavor. In extracting color and flavor we’re trying to break down the cell walls and release the flavor and color compounds. We’ve been very successful at it. That’s our new big thing!
As you probably know alot of wineries in the Central Valley and in the warmer regions have difficulty getting sufficiently color and flavor from certain grape varieties or even from the good grape varieties like Merlot and Cabernet Sauvignon. But also, say, in the North Coast, take Cabernet, for example, if you can extract color and flavor by skipping the cold maceration step, which takes two or three days, alot of energy cooling it down and then heating the must up later on, applying enzymes and all these sorts of things, you can skip all those processes by simply passing the must through a flow cell that sonicates the must to give you the color and flavor you want. You’d be saving mega bucks. Tank space, as well.
End of Pt. 2