User Rating:  / 1

Details

Last Updated on Wednesday, 16 November 2011 10:28

Pitching the Yeast, Discussion on Good Bacteria and Bad Bacteria and Getting the Pitching Temperature Right

The general process of pitching the yeast into the wort refers to the point where you have mixed everything up in the fermenter, topped it up to the required level with water and you are ready to add the brewers yeast.

Adding the yeast dry or dry yeasting is simply cutting open the packet of yeast and sprinkling it over the surface of the wort. This simple technique works just fine.

However, I prefer to re-hydrate the brewers yeast first. What this means is dissolving the yeast in water so it goes into the wort in liquid form, not as dry powder.

So why would you do this? I do it because I think it gives the good bacteria contained in the yeast the best chance of establishing themselves in the wort and multiplying quickly. The yeast is more active when it goes in. In my mind it is the same as when you bake bread. Bakers always re-hydrate their yeast in luke warm water to 'activate it' before putting it into the mixture. So to me it makes sense to active the brewers yeast before pitching it into the wort as well.

But there is a more compelling reason to re-hydrate the yeast. When you sprinkle it on the surface dry, a fair bit of it floats out to the side and sticks there above the maximum level (due to foam at mixing) and dries. Pouring in hydrated yeast avoids this. So using the yeast rehydrated simply make clean-up easier.

To re-hydrate the brewers yeast, simply empty the packet into a sanitized cup and full with luke warm water. Make sure it is luke warm only as hot water will kill the yeast. Cold water would be better than using hot water but luke warm is best. Stir it and let it sit. Keep coming back to it and stir some more. Even though it can stick to the spoon, it will dissolve eventually. Allow about 10 minutes to hydrate or dissolve properly.

When to Pitch the Yeast

If you have ever read the instructions that come with your can of home brew mix, they will usually talk about the ideal temperature to pitch but will also say pitching the yeast as soon as possible is more important. Timing is more important than temperature.

The reason can be explained by discussing good bacteria and bad bacteria. I won't use the scientific names for the different strains of bacteria, but lets call the yeast the good bacteria and everything else the bad bacteria.

No matter how well you sanitize, there will always be bad bacteria present. Least not because none of us sanitize the water we use to top up the fermenter along with the many other sources for bad bacteria like particles in the air.

When you pitch the yeast, the good bacteria immediately start multiplying in their millions. If the bad bacteria haven't been allowed to take hold of the wort, then the good bacteria will soon vastly out number the bad bacteria and take dominate the brew. This is what you want because the good bacteria are what converts the sugars to alcohol.

Delaying the pitching of the yeast just gives the bad bacteria a chance to multiply to the point where they can dominate and kill the good bacteria.

So this is why it is important to pitch as as the wort is ready with no delays.

Getting the Temperature for Pitching Right

While it is most important to pitch the yeast as soon as possible, to get the best results you still need to control temperature as best you can.

In pretty much all cases the problem is getting the temperature low enough after you have finished dissolving and mixing the ingredients in boiling water. There a couple of techniques you can use.

The most common is sitting the fermenter in a vat or batch with ice blocks and water surrounding it. Also put some water into sanitised jugs a couple of hours before you brew. The cold water will help get the temp down.

It is not recommended to put ice cubes in the wort unless you know they are pure. I have done it and it does work, but it is asking for trouble. Just make sure the ice is pure and isn't housing a lot of bacteria.

• < Prev
• Next >