Auto-parse multi-unit string

[superroma]

Here is a recipe for Stone Pale Ale:

Stone Pale Ale Yield: 5 Gallons (about 54 12-ounce bottles or 30 22-ounce bottles)

• 10 pounds plus 7 ounces crushed North American two-row pale malt
• 1 pound plus 4.2 ounces crushed 60L crystal malt
• 4.8 ounces crushed 75L crystal malt
• About 9 gallons water
• 0.44 ounce Columbus hops (12.9% alpha acid)
• ½ tsp Irish moss
• 0.77 ounce Ahtanum hops (6.0% alpha acid)
• 1.19 ounces Ahtanum hops (6.0% alpha acid)
• 1 (35ml) package White Labs WLP007 Dry English Ale Yeast or WLP002 English Ale Yeast
• 1 cup plus 3 Tbsp light dried malt extract

As you can see, there are lot of stings like "10 pounds plus 7 ounces". I would like editors to be able to parse such string and auto convert them to the currently selected unit.