Short answer: the Preserves Jar accepts 36 crops. Measured by extra gold per machine per day, the best are Starfruit (568g), Ancient Fruit (424g) and Pumpkin (258g). The list changes a lot if you have only a few machines, because a machine that is always busy earns more from a fast, valuable crop than a slow, cheap one.
How to read the table
"Extra gold per machine per day" is the price of the product minus what the crop would have sold for raw, spread over the days the machine takes, assuming it is never idle and the Artisan profession is on. It is the number to use when you own fewer machines than you have crops. If you have more machines than crops, rank by total gold instead, which is what the Keg vs Preserves Jar tool does with your real harvest. Times use 1,600 game minutes per day, as the wiki states.
| # | Crop | Makes | Price | Days | Extra gold per machine per day |
|---|---|---|---|---|---|
| 1 | Starfruit | Jelly | 2,170g | 2.5 | 568g |
| 2 | Ancient Fruit | Jelly | 1,610g | 2.5 | 424g |
| 3 | Pumpkin | Pickles | 966g | 2.5 | 258g |
| 4 | Pineapple | Jelly | 910g | 2.5 | 244g |
| 5 | Red Cabbage | Pickles | 798g | 2.5 | 215g |
| 6 | Melon | Jelly | 770g | 2.5 | 208g |
| 7 | Rhubarb | Jelly | 686g | 2.5 | 186g |
| 8 | Cauliflower | Pickles | 560g | 2.5 | 154g |
| 9 | Artichoke | Pickles | 518g | 2.5 | 143g |
| 10 | Yam | Pickles | 518g | 2.5 | 143g |
| 11 | Amaranth | Pickles | 490g | 2.5 | 136g |
| 12 | Strawberry | Jelly | 406g | 2.5 | 114g |
| 13 | Kale | Pickles | 378g | 2.5 | 107g |
| 14 | Beet | Pickles | 350g | 2.5 | 100g |
| 15 | Taro Root | Pickles | 350g | 2.5 | 100g |
| 16 | Radish | Pickles | 322g | 2.5 | 93g |
| 17 | Bok Choy | Pickles | 294g | 2.5 | 86g |
| 18 | Grape | Jelly | 294g | 2.5 | 86g |
| 19 | Potato | Pickles | 294g | 2.5 | 86g |
| 20 | Cactus Fruit | Jelly | 280g | 2.5 | 82g |
| 21 | Cranberries | Jelly | 280g | 2.5 | 82g |
| 22 | Broccoli | Pickles | 266g | 2.5 | 78g |
| 23 | Eggplant | Pickles | 238g | 2.5 | 71g |
| 24 | Garlic | Pickles | 238g | 2.5 | 71g |
| 25 | Powdermelon | Jelly | 238g | 2.5 | 71g |
| 26 | Tomato | Pickles | 238g | 2.5 | 71g |
| 27 | Blueberry | Jelly | 210g | 2.5 | 64g |
| 28 | Corn | Pickles | 210g | 2.5 | 64g |
| 29 | Summer Squash | Pickles | 196g | 2.5 | 60g |
| 30 | Green Bean | Pickles | 182g | 2.5 | 57g |
| 31 | Hot Pepper | Jelly | 182g | 2.5 | 57g |
| 32 | Carrot | Pickles | 168g | 2.5 | 53g |
| 33 | Parsnip | Pickles | 168g | 2.5 | 53g |
| 34 | Unmilled Rice | Pickles | 154g | 2.5 | 50g |
| 35 | Hops | Pickles | 140g | 2.5 | 46g |
| 36 | Wheat | Pickles | 140g | 2.5 | 46g |
Reading the top of the list
A Preserves Jar finishes every fruit and vegetable in 2.5 game days, much faster than the Keg's wine, so it earns well on cheap crops: it needs fewer machines to keep up. Its best crops are those with a high price after processing, and the list rewards value more than volume. Among the five best, Starfruit makes Jelly worth 2,170g.
Each crop has its own page with profit per tile, fertilizer and the other machine. See also How many kegs do I need? for how many machines one plant keeps busy, and Best Greenhouse Setup for Money for the keg count that decides the greenhouse crop.