Plastic Cap

This is a SINGLE Solid Cap for a Wide-Mouth Mason Jar. This Cap can be used in conjunction with a Wide-Mouth Mason Jar - for storing your crop after harvest.

These Tough Tops brand are made of bright white plastic. They are very durable. BPA-free. 12 sided for extra grip. There is a gasket inside for extra seal. These Caps are sold individually.


If you order 4 we will throw in the box! :)

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Print Instructions

Jar Sprouting Instructions

Specific Sprouting Instructions are found on the page devoted to the Seed or Mix you are growing. Below are the specifics of Jar Sprouting. All steps take for granted that you have a Screen Lid attached to your Jar.

Seed Prep

Not all seeds require this step. See the seed information page to see if you need to do this for the seed you are sprouting. Skip this step if you don't have a screen with mesh smaller than your seeds.

Fill the Jar with water. Twirl and twirl and twirl the water around in the Jar. Pour water out and repeat the fill and twirl and pour until the water runs clear.


Fill your Jar with cool (60 - 70°) water unless instructed otherwise by your seed supplier (us, we hope =;-) and leave to soak for 8 - 12 hours, or for the time noted for the specific seed/mix you are sprouting.


Fill your Jar with cool (60 - 70°) water. Twirl and twirl the Jar. Pour water off and repeat once or twice more. As a rule we do it 2-3 times every time we Rinse. We Rinse and Drain 2-3 times daily.


This is the hardest part of Jar sprouting. It is also the best reason to have screw on Screen Lids. When you are done Rinsing you need to get as much of the water out of the Jar as possible. With a Jar all you can really do is use gravity, so turn it Screen down and shake it up and down over and over and over again until no more water comes out through the Screen. When you are growing big seeds it is easy enough to get most of the water out, but when they are small seeds, there will always be some water left, so shake more than you think is necessary.


We always put our Jars face down - at an angle - jar sprouting,growing sprouts in a jarbetween Rinsing and Draining. We will use our dish rack in the rare event that it isn't full of dishes, or more often, we use high rimmed bowls which the Jar rests on, and which captures the excess water that inevitably drains out, even after our thorough Draining. You can get away with leaving the Jar upright if you are growing big seeds (see Perfect, above), but when you grow small seeds (those listed above as Good Matches) they end up sitting in water (that water which we can't believe is even there, because we drained so thoroughly after Rinsing). Actually it is only the very bottom seeds/sprouts that are sitting in water, but they don't much like it and they can spoil your whole crop. So, set the Jar - at an angle - face down between Rinsing and Draining! It can also improve air-circulation (not if you use a bowl as pictured, but certainly if you use the dish drainer or something open like that).

If you have our Screen Lid Set - or another set of Screens, of various mesh sizes - change your Screen as your sprouts grow, unless you started with the widest mesh Screen, of course. When growing seeds that shed their hulls, especially small seeds like Leafy Sprouts and Brassicas - which grow leaves; moving to a wider mesh screen allows hulls to escape when you Rinse and Drain. Always use the widest mesh screen you can - regardless of what crop you are growing. As long as your seeds/sprouts aren't escaping - you're using the right screen. The wider mesh also makes Draining easier, and slightly improves air-circulation.


We always suggest a low-light, 70° location for your sprouter, until it is time for Greening (if you are growing sprouts that green (anything that grows a leaf - like Leafy or Brassica sprouts). At that point we often say: Move your sprouter to a brighter location (or words to that affect), and though we always say to avoid direct sunlight, we will tell you strongly: Never put a Jar in direct sunlight - unless you wish to cook your sprouts! The lack of air-circulation built into Jars makes them the most vulnerable to heat build-up, so if you are Greening sprouts in a jar, don't move them to a too bright a location, but rather, concentrate on that other thing we say: You'll be amazed at how little light it takes to turn your sprouts green!

Harvest and Crop Storage

Before Harvesting any crop, it is essential that you Drain it Very Thoroughly after your final Rinse. Storing crops that are dry to the touch, maximizes their shelf life. Draining, when growing in a Jar is always a bit more work, so pay especially close attention to this. Drain thoroughly! If you are growing Leafy or Brassica sprouts, you can use our De-Huller to remove any remaining hulls, and dry your crop at Harvest time.

If you want to Store Your Crop using a Jar, all you need is to screw a Solid Lid onto your Jar, before putting it in your refrigerator.

Seed Specific Sprouting Instructions

If you have a particular seed type in mind, read on to discover further details of Jar Sprouting that seed type. Refer to the seed's main information page for detailed instructions.


Follow instructions on this page for Jar specifics and on the seed/mix detail page for all bean specifics.

Maximum dry seed per Quart = 1.5 cups

Mung Bean

You can't grow big thick Mungs in a Jar unless you want to break the Jar when they're done - that's the only way you'll get the sprouts out. SO, grow the sweet and tiny Mungs when using a Jar!

Maximum dry seed per Quart = 1.5 cups


Broccoli, Radish, Cabbage, etc. need to move while sprouting or they will form a root mass (beginning around day 3) which is at least unpleasant and often lessens the sprouts' quality. Solution: Break Up/Loosen the mass. Fill the Jar with water, take a fork and use it to loosen the sprout mass. If the Jar is too full, transfer them to a bigger container for the loosening. Keep breaking up the mass at every Rinse after that too.

You will also get rid of hulls by changing your Screen Lid as your sprouts grow. Use the widest mesh you can. Always. As long as your sprouts aren't falling through the Screen, you're using the right Screen.

Do not try to grow mucilaginous seeds in a Jar!

Maximum dry seed per Quart = 3 Tablespoons

Leafy Sprouts

One issue folks have with these sprouts is that they expect them to be green. There are - almost always - regardless of the sprouting method - some sprouts which will not turn green. Those that grow in the center of the crop - their leaves will remain yellow. Our advice is: Live with it! Most will green if you don't over-crowd the sprouter (use 2 Tbs. or less of seed) - and those that don't are still plenty delicious, nutritious and they add beauty (yellow goes well with green and white!) too. Leafy sprouts will shed their hulls more readily if they are allowed to move freely, so break up the mass on day 4 and 5 and maybe 6. Fill the Jar with water and kinda pull the mass apart with a fork type implement. It isn't a critical issue with the Leafy Sprouts, but it doesn't hurt.

You will also get rid of hulls by changing your Screen Lid as your sprouts grow. Use the widest mesh you can. Always. As long as your sprouts aren't falling through the Screen, you're using the right Screen.

Maximum dry seed per Quart = 2 Tablespoons


Garlic, Onion , Fenugreek, etc. require no extra work - though they do take more time. Be sure to drain the Jar well after each Rinse so that the seeds/sprouts aren't sitting in water (not only will those that sit in water sprout poorly - they'll smell REALLY bad!) and remember - Alliums all take up to 2 weeks to finish sprouting so keep Rinsing and Draining if it's Alliums you be growing.

Maximum dry seed per Quart = See the detailed page for the Seed or Mix you are growing.


Follow Seed specific AND Jar specific instructions.

Maximum dry seed per Quart = 1.75 cups

Nuts and Seeds

Follow Seed specific and Jar specific instructions.

Maximum dry seed per Quart = 1.5 cups

Seeds and Pseudograins

Follow Seed specific and Jar specific instructions.

Maximum dry seed per Quart = 1.5 cups

Critter Sprouts

Follow Mix specific and Jar specific instructions.

Maximum dry seed per Quart = 1.5 cups

Grass and Greens

Pre-Sprouting Only! Fill your Jar all the way, with water, when Soaking Sunflower Greens. Use a Screen Lid too, to keep them under water.

Maximum dry seed per Quart = 1.5 cups


Pre-Sprouting only! Never mucilaginous seeds!

Maximum dry seed per Quart = See Seed Information page for the seed or mix you are Pre-Sprouting.

These are Solid BPA-Free Plastic Wide-Mouth Lids @:-)

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