One of the most frequent questions I get asked by customers is: How much culture do I use when making yoghurt?
Cultures come in packets that are labelled with how many litres of milk they will inoculate. Our yoghurt cultures come in a packet that will inoculate 100 litres of milk. How much is in the packet will vary from culture to culture and batch to batch of the same culture. Remember, it’s alive, so it will not be the same for every batch that is grown. Culture is not measured by weight or volume, but rather by its rate of activity.
The activity rate of a culture is most easily determined by measuring the acid production or decrease in pH of the milk it is added to. In order to have an easily understandable system, the growing conditions are standardised by having the same medium, temperature and time. For example, the use of a standard weight/volume percentage concentration (w/v) reconstituted skimmed milk, at 30oC for six hours.
So if you get a packet of yoghurt culture that does 100 litres and you want to make two litres of yoghurt, you would use 2/100 of the packet (1/50th), regardless of whether the weight has changed from batch to batch for that culture.
Bring the sachet to room temperature before opening it for the first time. This should only take a few minutes and reduces the effect of condensation causing some of the culture to stick to the inside of the sachet. Cut all the way across the top of the sachet and using a sharp, pointed knife empty the culture into one of the sterile jar supplied. Using a shard, pointed knife allows you to get right into the corners of the packet to get all of the culture out.
Once you have all of the culture out of the packet into the first sterile jar, take a look at it. This is enough for 100 litres and is your main ‘storage jar’. Now estimate 1/10th of the contents of the first sterile jar and place into the sterile second jar. This becomes your ‘working supply’, label both jars and store in the freezer.
Your ‘working supply’, being approximately 1/10th of the original supply of culture, will make approximately 10 litres of yoghurt. Now you are getting the idea of how small the amount of culture is that you need to use. Use the tip of a sharp, pointed knife to get the amount of culture you need to use for the size batch you are going to do. I usually do a two-litre batch, but you might be doing a one-litre batch.
The most common problem people have with this is using too much culture. If you do accidentally use not enough; no big problem. Remember the culture is alive and if kept at the correct temperature, it is going to double about every 30 minutes. The Green Living Australia yoghurt maker is designed to keep the temperature accurate over extended fermentation times, so wait half an hour longer and you have doubled your culture.
From time to time I am asked why we do not supply a simpler way to do this. Why don’t we have a one sachet system so you can just tear open a packet and add it; no measuring; no guessing. That would be great, but unfortunately, so would the cost. There is a product out there like that and we are compared to them all the time. How easy would it be if the Green Living Cultures could be packed in these convenient packets? Well, let’s have a look at what you are getting in regards to convenience and how much you are paying for it.
I did a Google search on yoghurt making cultures and I found the price to be $4.20 for a packet that makes one litre. It is mostly powdered milk and you just add water. So for 100 litres that is $420.00. Now compare that to $22.95 for 100 litres of the Green Living Australia culture. You do have to add the Green Living Australia culture to milk, so you are up for another $150.00 there. Overall saving to you is approximately $250.00. Is that worth a few minutes of your time?
How to store the culture and how much to use.
This system will help you get the best value out of our yoghurt cultures, kefir and probiotic veggie culture while helping protect the culture from moisture and contamination.