Investors interested in Beverages - Alcohol stocks are likely familiar with Heineken NV (HEINY) and The Duckhorn Portfolio, Inc. (NAPA). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The Zacks Rank favors stocks with strong earnings estimate revision trends, and our Style Scores highlight companies with specific traits.Currently, both Heineken NV and The Duckhorn Portfolio, Inc. are holding a Zacks Rank of # 2 (Buy). This system places an emphasis on companies that have seen positive earnings estimate revisions, so investors should feel comfortable knowing that these stocks have improving earnings outlooks. However, value investors will care about much more than just this.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.HEINY currently has a forward P/E ratio of 19.28, while NAPA has a forward P/E of 31.59. We also note that HEINY has a PEG ratio of 1.35. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. NAPA currently has a PEG ratio of 2.58.Another notable valuation metric for HEINY is its P/B ratio of 2.34. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, NAPA has a P/B of 2.63.These metrics, and several others, help HEINY earn a Value grade of B, while NAPA has been given a Value grade of D.Both HEINY and NAPA are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that HEINY is the superior value option right now. Special Report: The Top 5 IPOs for Your Portfolio Today, you have a chance to get in on the ground floor of one of the best investment opportunities of the year. As the world continues to benefit from an ever-evolving internet, a handful of innovative tech companies are on the brink of reaping immense rewards - and you can put yourself in a position to cash in. One is set to disrupt the online communication industry. Brilliantly designed for creating online communities, this stock is poised to explode when made public. With the strength of our economy and record amounts of cash flooding into IPOs, you don’t want to miss this opportunity.>>See Zacks’ Hottest IPOs NowWant the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Heineken NV (HEINY): Free Stock Analysis Report The Duckhorn Portfolio, Inc. (NAPA): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research