Investor beware: The mutual funds in which you invest may support companies that are working against your sustainable food system values. ‘Tis the season to dump those stocks, in the form of year-end donations to causes you do support. This is a strategy I learned last December, and it helped one of my favorite nonprofits attract an unexpected $20,000 gift.

It’s true. Take a closer look at your investment statements, and you may discover you own shares of companies that are connected to, for instance, factory farms, exploitation of farmworkers, or peddling junk food to the masses.

Even if you don’t directly own stock in companies that you would prefer to avoid, many people are surprised to find that their mutual funds hold those stocks. (The host of the Kathleen Show, for example, discovered she owned McDonalds and blogged about it last year.)

I have yet to discover a super-easy way to determine what exactly is in a mutual fund–there’s a future Food+Tech Hackathon project–but it’s not that hard to download a fund’s prospectus (you’ll find it somewhere in the managing company’s Web site) and scan the “holdings” section. It took me less than five minutes to discover that the top two holdings of a mutual fund that made up a significant portion of my portfolio were Nestlé and BP. Anheuser-Busch was in the top 10, as well.

Though it was very easy for me to decide that I had no interest whatsoever in keeping this fund, there was one small rub: I purchased my shares years ago, at a price much lower than what they are worth now. So if I were to sell them outright, I would owe capital gains taxes on the difference.

But I did want to clean up my portfolio. Furthermore, I needed to tap my investments to make several year-end donations. So here’s what I did:

About this time last year, my friend Eric Becker at Clean Yield Asset Management outlined a win-win solution for me, and anyone else in a similar situation: donate the mutual funds (or stocks, as the case may be) themselves, rather than giving cash. These gifts are as tax deductible as cash donations, and because I don’t have to pay capital gains taxes, I can give more. The nonprofits can immediately sell the offending stocks or funds, reaping their current value without incurring any penalties. Voila, we no longer own any of Nestlé’s stock.

Indeed, it turns out that this is not much more complicated than selling the stock or mutual fund if the organizations you wish to support already have brokerage accounts set up, allowing them to accept these types of donations. Simply ask the organization for their specific instructions. In the case that your chosen nonprofits do not already have brokerage accounts set up, you can give them an even greater gift by encouraging them to make this donation option available to would-be donors.

Last year, I called La Cocina, a nonprofit in San Francisco that helps low-income women, primarily immigrants or women from communities of color, break out of the cycle of poverty by forming their own sustainable, food-based businesses. It turns out they weren’t set up to accept stock or fund donations, but they moved quickly to make it happen. A week later, they sent an email to their entire list announcing this new way to make donations, with a hint that this might be a good time to make changes to an investment portfolio to bring it more in line with La Cocina’s values.

Almost immediately, someone made an unexpected $20,000 gift in the form of stock. Talk about leverage: My donations may be tiny in comparison, but I am thrilled that my inquiry opened up a whole new channel for charitable giving at La Cocina. Perhaps this story will inspire you to donate stocks or mutual funds that don’t quite fulfill your intentions? That would truly be a gift that keeps on giving.