Value of "Kill Step"/"Microbial Control" without impacting flavor

[AJ Davis]

Hi All!

I am trying to approximate the value of a new kill step technology for the wine industry. Would winemakers value a cold, mechanical pasteurization tool (no chemicals, filtration, or heat) that kills microbes in wine without impacting flavor? It is highly effective against all spoilage microorganisms as well as yeast, so it could also be used for precision fermentation. If so, any idea how to quantify the value, for example, would commercial winemakers pay an additional $0.05 per liter for this capability? Thanks!

 

[BarrelMonkey]

One way to figure out the value of your proposed technology would be to look at the cost of what's currently used in the industry for this purpose.

Velcorin is used by some winemakers (and, incidentally, many soft drink makers) as a kill step prior to bottling. It's frowned on by some since in itself it's quite a toxic chemical, though it breaks down rapidly and is not present in the final product. The dosing apparatus is expensive, so unless you're a very big producer you'll probably contract with a mobile supplier. Typical costs are $0.12 to $0.18 per liter with some sort of set up fee/minimum charge.

Another option in current use is filtration. Lenticular filters cost a few $100 each as do sterile (0.45um) filters, and depending on your starting NTUs you'll likely need to do at least 1 lenticular step followed by sterile polishing. Again, some folks think that filtration detracts from the wine but it is widely used. You can probably get at least a few thousand liters through such a filter system (and some designs of lenticular filter can be backflushed to increase their useful life), so I imagine the per liter cost is in the same ballpark as above, maybe a bit less. However, you need to make the upfront investment in filter housings which will be another few thousand $$. Alteratively there are mobile filtration units that you can hire, (either full service or client operated) which may make sense from a cost point of view.

 

[Johnd]

And then there is a very significant number of wineries using only the very best fruit they can buy or grow, and conducting fermentation with the wild yeast that’s present on the fruit, frowning upon microbial elimination. This microbial elimination, I’m assuming, would also kill the malolactic bacteria found on the harvested grapes.

Some wineries wouldn’t use this technology much, if at all. I’d imagine that the mass producers may embrace such a step in the process, and that market is huge!!!

 

[BarrelMonkey]

And then there is a very significant number of wineries using only the very best fruit they can buy or grow, and conducting fermentation with the wild yeast that’s present on the fruit, frowning upon microbial elimination. This microbial elimination, I’m assuming, would also kill the malolactic bacteria found on the harvested grapes.

Some wineries wouldn’t use this technology much, if at all. I’d imagine that the mass producers may embrace such a step in the process, and that market is huge!!!

To clarify, we are talking about different steps in the winemaking process. There are winemakers who, as you say, rely on native yeast and malolactic bacteria to achieve fermentation and stylistic character - but who still want to bottle a sterile product. In particular, if you're producing, say, a white wine with some degree of residual sugar in the finished wine, a kill step prior to bottling might be considered important if you don't want to end up with cloudy and maybe fizzy wine. (Though there are some winemakers who still eschew any sort of processing - I know of one who consistently produces lovely whites with no filtering or fining and certainly no chemical treatment other than sulfites).

 

[Johnd]

To clarify, we are talking about different steps in the winemaking process. There are winemakers who, as you say, rely on native yeast and malolactic bacteria to achieve fermentation and stylistic character - but who still want to bottle a sterile product. In particular, if you're producing, say, a white wine with some degree of residual sugar in the finished wine, a kill step prior to bottling might be considered important if you don't want to end up with cloudy and maybe fizzy wine. (Though there are some winemakers who still eschew any sort of processing - I know of one who consistently produces lovely whites with no filtering or fining and certainly no chemical treatment other than sulfites).

Agreed, I was referring to treatment prior to fermentation, if this is only an “end of the winemaking process”, could be a different story. I was a little fuzzy on the OP’s “precision fermentation” term, if it’s meant to stop fermentation in its tracks at any particular time to preserve some residual sugar, I can also see some very beneficial uses. I’d expect that sulfites would still have a place, at least for oxidation protection.

 

[AJ Davis]

One way to figure out the value of your proposed technology would be to look at the cost of what's currently used in the industry for this purpose.

Velcorin is used by some winemakers (and, incidentally, many soft drink makers) as a kill step prior to bottling. It's frowned on by some since in itself it's quite a toxic chemical, though it breaks down rapidly and is not present in the final product. The dosing apparatus is expensive, so unless you're a very big producer you'll probably contract with a mobile supplier. Typical costs are $0.12 to $0.18 per liter with some sort of set up fee/minimum charge.

Another option in current use is filtration. Lenticular filters cost a few $100 each as do sterile (0.45um) filters, and depending on your starting NTUs you'll likely need to do at least 1 lenticular step followed by sterile polishing. Again, some folks think that filtration detracts from the wine but it is widely used. You can probably get at least a few thousand liters through such a filter system (and some designs of lenticular filter can be backflushed to increase their useful life), so I imagine the per liter cost is in the same ballpark as above, maybe a bit less. However, you need to make the upfront investment in filter housings which will be another few thousand $$. Alteratively there are mobile filtration units that you can hire, (either full service or client operated) which may make sense from a cost point of view.

Thank you so much for your comprehensive reply! I currently have a pretty large spreadsheet attempting to model per liter costs for Velcorin and Sterile Filtration based on various capital and variable costs (e.g. from Scott and Pall). Depending on facility volume, estimates have been coming in between $0.09 - $0.19/liter. I had no idea about the mobile services! These examples (Velcorin, Filtration) seem to track with your estimates. This is all very helpful in trying to triangulate baseline market pricing.

Do you think commercial winemakers (and other beverage producers) generally find the usage-based pricing compelling? I am sure this varies by facility size, but I suppose given the mobile services there is some evidence of market acceptance. Definitely pros and cons of both capital expenditure and operating lease/pay-per-use schemes.

 

[AJ Davis]

Agreed, I was referring to treatment prior to fermentation, if this is only an “end of the winemaking process”, could be a different story. I was a little fuzzy on the OP’s “precision fermentation” term, if it’s meant to stop fermentation in its tracks at any particular time to preserve some residual sugar, I can also see some very beneficial uses. I’d expect that sulfites would still have a place, at least for oxidation protection.

Great insights! Based on initial testing and discussion with winemakers, we are hopeful it can be a tool that can be used at multiple stages in the production process. Both pre-packaging as additional insurance against spoilage and secondary fermentation as well as JohnD's note on "stopping fermentation in its tracks" ("precision fermentation" definitely seems a little fuzzy - that is helpful feedback).

So, if we can keep pricing at or below some of the estimates mentioned above, provide better microbial killing than existing methods like Velcorin/Sterile Filtration, without impacting flavor/color there might be a decent value proposition for commercial winemakers?

 

[BarrelMonkey]

Thank you so much for your comprehensive reply! I currently have a pretty large spreadsheet attempting to model per liter costs for Velcorin and Sterile Filtration based on various capital and variable costs (e.g. from Scott and Pall). Depending on facility volume, estimates have been coming in between $0.09 - $0.19/liter. I had no idea about the mobile services! These examples (Velcorin, Filtration) seem to track with your estimates. This is all very helpful in trying to triangulate baseline market pricing.

Do you think commercial winemakers (and other beverage producers) generally find the usage-based pricing compelling? I am sure this varies by facility size, but I suppose given the mobile services there is some evidence of market acceptance. Definitely pros and cons of both capital expenditure and operating lease/pay-per-use schemes.

I'm glad my estimates were in the same ballpark as yours!

I think that many (particularly smaller) winemakers rely on per-use pricing since the up-front costs are high for filtration and chemical sterilization. It's also convenient, particularly if you can get a provider to come onsite, they typically take care of all the setup and cleanup (of the filtering apparatus) as well as monitoring the filtration itself. Here are a couple of other (crossflow) filtration service providers: VA filtration, ATP.

A competitively priced method would of course be attractive, though I think most winemakers would want robust evidence that it (a) works and (b) does not negatively impact the wine before signing up. It might be worth thinking carefully about how to achieve this. For example, I think even the most ardent supporter of filtration would agree that it beats up the wine in the short term - but that the wine recovers afterwards. So, at least in the pre-bottling use case it might be necessary to go as far as bottling samples sterilized using your method vs, eg filtration, then waiting at least 3-6 months before analyzing and tasting them (in a randomized double blind manner of course!)