I’ve been using my starter named John Dough for over 1.5 years now and in the past 1-2 weeks I’ve noticed that it is very sluggish. This is either the second or third time that I have noticed this happening. The last time was early this summer, at that time I fed it rye for several days and then went back to my usual regimen of feeding it whole red fife once a week keeping it in the fridge between feeds. I would then make levains from it once or twice a week.
Now that this has happened twice I am starting to think that maybe whole red fife isn’t the ideal food for my starter. I do have a proofing box in case anyone wonders if the cooler weather is the cause of the sluggish behavior.
Rye seems to be one of the best flours to use to boost the growth of a starter and it worked so well the last time this happened so I’ve decided to switch my starter over. Over the past day and a half I’ve given it four feedings and with the third and fourth feedings the starter grew to 4 times. I’ve never had that with my old starter, at most I’d see a 3 times increase in volume. So I am thinking that switching to rye has already boosted my starter’s potency.
Now one very odd thing that I’ve always noticed with my old starter is that when I need to make an all white flour levain, it would never double. I would always have to add at least a small portion of some whole grain to it in order to get it to double, not ideal. So to test the new John Dough I decided to do a test levain feeding it 1:1:1 with white flour. Incredibly after 2 hours it doubled and after 3 hours it had peaked at 3 times increase in volume. I think that satisfies me that my starter is much improved at this point.
I have also been interested in the pH characteristics of my starter for some time and have been collecting data over the past few months. The reason I became interested in this is that I was concerned that my only weekly feedings were causing the starter to get too acidic. The concern with this is that if one transfers too high an acid load to the levain then the dough will be far too acidic. Not only can this affect the flavour but it can affect the crumb. As you may know, the proteolytic enzymes in the grain become more active once the pH is < 4. So if we transfer too much acid and the pH drops really early in the process of bulk or during final proof, the gluten network can be damaged and the structure of our bread and its ability to hold the gases will be harmed.
OK I’ll cut to the chase, by feeding weekly and keeping the starter in the fridge, the acid load did not build up over time, the pH did not get lower and lower each week. That was reassuring. So I wanted to see what the pH characteristics of the rye starter are.
When fed whole red fife I would see pH of about 3.6 one week after last feeding. Immediately after feeding pH would be around 5.2 then at peak after feeding pH around 4.2.
I’ve only measured on two cycles but after feeding rye immediately the pH would be around 4.65 and then at peak 3.6. I surmised that rye isn’t as good a buffer for the acid compared with red fife and that red fife has better buffering abilities than rye.
To test my hypothesis that red fife is a better buffer of acid than rye, which could explain the rye starter having lower pH than red fife starter I just did the following measurements.
Red fife 1:1 water pH 5.9
Rye 1:1 water pH 6.15
Our tap water pH 7.12
White vinegar pH 2.14
I diluted the vinegar 1:3 with tap water pH 2.39
Red fife pH 1:1 with diluted vinegar pH 3.63
Rye pH 1:1 with diluted vinegar pH 4.0
So I was quite wrong that red fife is a better buffer of acid than rye. The red fife starts at a lower pH than rye and the pH falls more than the rye when an equal acid load is added to it.
So why then does the starter being fed rye have a lower pH if it is actually a better buffer? The reason is this, because rye can buffer more acid, it allows the LAB to continue to produce more acid when fed rye and ultimately the pH drops more because the TTA (Total Titratable Acid) of the starter fed rye is higher. The LAB are actually more negatively affected by the acid in the starter/dough than the yeast are. So because the rye is able to buffer the acid produced by the LAB more effectively and longer, there ends up being more LAB in the rye starter and the total acid produced is higher eventually overcoming the rye’s ability to buffer the acid. With the lower buffering ability of red fife the LAB will be negatively affected by the acid sooner so their population will be less and the total acid produced will be less.
I think this is one of the reasons by I have always found that breads made with a portion of rye are more tangy than those without. Anyhow I hope some of you might find that interesting.
Benny