Horseradish loses heat - how to keep it hot?

My fresh horseradish is so hot even seasoned wasabi eaters can't keep it in thier mouth.  But when I grate it and pack it in jars, either in water or in vinegar, it loses it's heat.  The flavor is great but no kick.

My husbands grandmother always grated hers and packed it in jars and months later it still packed a punch.  What am I doing wrong?

Anyone here grow and put up horseradish?

I grow it, but alas I haven't tried it yet.  I planned on experimenting with it this fall to see what I could do with it.

Could it be the type of horseradish?  I wonder, maybe some hold their heat better - just a thought.

Even the store-bought bottles do that...after a few weeks in the fridge, they get real mild.
While vinegar is the most common liquid for preserving horseradish, vinegar is also used to dilute the heat of it.  Keeping oxygen out of the bottle will prolong the heat/flavor...pack them full...NO air space.

Thanks for the tip.  I will have a great harvest this year and I do love horseradish - the hotter the better.

can you harvest horseradish as needed? I have started a patch this year for the first Time and Look forward to using it. Can you just dig it when ever...or does it have to be in the spring or fall?

Supposedly the best flavor is after the first, maybe even second killing frost; the cold is supposed to enhance the flavor.  Here in South Carolina I could be waiting until after Christmas.  I do wait until then to pull up the entire plant but I have been known to dig down under the plant and steal a few small side shoots.  The little side shoots sometimes seem even hotter than the bigger roots.

A tip if you haven’t processed horseradish before:  when they say it is best to grate it outside – it is.

OK Good to know!

If you do grate it indoors, do it in front of an open window with an exhaust fan!